Study of H-Zeolite Addition in The Esterification Step of ... - ITS
Study of H-Zeolite Addition in The Esterification Step of ... - ITS
Study of H-Zeolite Addition in The Esterification Step of ... - ITS
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<strong>The</strong> First International Sem<strong>in</strong>ar on Science and Technology<br />
January 24, 2009<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
<strong>Study</strong> <strong>of</strong> H-<strong>Zeolite</strong> <strong>Addition</strong> <strong>in</strong> <strong>The</strong> <strong>Esterification</strong> <strong>Step</strong> <strong>of</strong> Biodiesel Synthesis<br />
from used Cook<strong>in</strong>g Palm Oil<br />
Introduction<br />
Karna Wijaya, Triyono and Risqi And<strong>in</strong>i<br />
Laboratory <strong>of</strong> Physical Chemistry,<br />
Department <strong>of</strong> Chemistry, Gadjah Mada University<br />
Jl.Kaliurang, Km 5.5, Sekip Utara, Yogyakarta 55218<br />
Telp./Fax.: 0274-545188<br />
Correspondence author: karna_ugm@yahoo.com, Mobile phone: 08122692493<br />
Abstract<br />
It has been studied the effect <strong>of</strong> H-zeolite addition <strong>in</strong> esterifiction step <strong>of</strong> biodiesel synthesis from used<br />
cook<strong>in</strong>g palm oil us<strong>in</strong>g a ste<strong>in</strong>lessteel biodiesel reactor with capacity <strong>of</strong> 10 L and equipped with an automatic<br />
temperature control, a timer, and a stirrer.<br />
<strong>The</strong> study was <strong>in</strong>itiated with natural zeolite activation us<strong>in</strong>g technical sulfuric acid. After activation the<br />
zeolite was characterized its acidity by gravimetric method, its structure by X-ray diffractometry, and FT-IR.<br />
<strong>The</strong> H-zeolite then was used as solid acid catalyst <strong>in</strong> esterification step <strong>of</strong> biodiesel synthesis to decrease the<br />
free fatty acid concentration <strong>in</strong> used palm oil. <strong>The</strong> H-zeolite which was used <strong>in</strong> the process was varied its<br />
weight towards (oil + methanol) weight i.e. 1.50%; 3.50%; 5.50% and 6.50%. As a comparison, pretreatment<br />
<strong>of</strong> used cook<strong>in</strong>g palm oil also has been done over 1.50 % sulfuric acid. After pretreatment, the oil was<br />
separated from methanol and H-zeolite, the reaction was cont<strong>in</strong>ued by transesterify<strong>in</strong>g the oil with methanol<br />
us<strong>in</strong>g NaOH as catalyst. <strong>The</strong> transesterification product then was labeled as biodiesel. Both esterification and<br />
transesterification process were carried out <strong>in</strong> a ste<strong>in</strong>lessteel biodiesel reactor at temperature <strong>of</strong> 70 o C for 2<br />
hours. <strong>The</strong> composition <strong>of</strong> the biodiesel was analyzed us<strong>in</strong>g Gas chromatography–Mass Spectroscopy (GC-<br />
MS), 1 H-NMR and their physical properties were analyzed us<strong>in</strong>g ASTM analysis methods.<br />
<strong>The</strong> research results showed that activation resulted <strong>in</strong> no destruction <strong>of</strong> zeolite structure and <strong>in</strong>creased its<br />
acidity. Biodiesel reactor can used for biodiesel synthesis from used cook<strong>in</strong>g palm oil. <strong>Addition</strong> <strong>of</strong> H-zeolite<br />
<strong>in</strong> esterfication could decrease its free fatty acid content. Increas<strong>in</strong>g <strong>of</strong> H-zeolite would <strong>in</strong>crease the biodiesel<br />
conversion. <strong>The</strong> highest conversion <strong>of</strong> biodiesel was 98,41% achieved by addition <strong>of</strong> H-zeolite <strong>of</strong> 5.5%<br />
(w/w). <strong>The</strong> result <strong>of</strong> GC-MS analysis showed that ma<strong>in</strong> components <strong>of</strong> biodiesel were mixture <strong>of</strong> methyl<br />
esters with methyl oleic as the major compound (40.66%). Based on the ASTM analysis data, the obta<strong>in</strong>ed<br />
biodiesel specification was <strong>in</strong> agreement with diesel fuel specification for automotive.<br />
Key words: esterification,transesterifiction, biodiesel, used palm oil, H-zeolite,<br />
<strong>The</strong> <strong>in</strong>ternational demand for biodiesel and<br />
the promotion <strong>of</strong> the oil as sources <strong>of</strong> renewable<br />
energy which can decrease the greenhouse effect are<br />
<strong>in</strong>creas<strong>in</strong>g year after year. Biodiesel can be used <strong>in</strong><br />
almost diesel eng<strong>in</strong>e when mixed with fossil diesel<br />
oil. Biodiesel can provide benefits <strong>in</strong>clud<strong>in</strong>g:<br />
reduction <strong>of</strong> greenhouse gas emissions and fossil fuel<br />
use, <strong>in</strong>crease rural development and a susta<strong>in</strong>able fuel<br />
supply. However, biodiesel have some limitations<br />
such as the feedstocks for bi<strong>of</strong>uel production must be<br />
replaced rapidly [1-10]<br />
Biodiesel is consist<strong>in</strong>g <strong>of</strong> fatty-acid alkyl<br />
esters, known as FAME (fatty-acid methyl ester).<br />
Fatty-acid alkyl esters are long cha<strong>in</strong>s <strong>of</strong> carbon<br />
molecules with an alcohol molecule attached to one<br />
end <strong>of</strong> the cha<strong>in</strong>. In a process called<br />
transesterification, vegetable oils, animal fats or<br />
restaurant greases are comb<strong>in</strong>ed with alcohol and<br />
chemically altered to form fatty esters such as methyl<br />
ester [8-14]<br />
Beside fresh vegetables oil, used cook<strong>in</strong>g oil<br />
may be used as raw material for biodiesel syntheses.<br />
However, used cook<strong>in</strong>g oil which has been heated <strong>in</strong><br />
high temperature usually conta<strong>in</strong> high concentration<br />
<strong>of</strong> free fatty acids. Free fatty acids will create soap<br />
and h<strong>in</strong>der the formation <strong>of</strong> biodiesel <strong>in</strong><br />
transesterification reaction step. One <strong>of</strong> the method to<br />
deal with this is by giv<strong>in</strong>g a prelim<strong>in</strong>ary treatment on<br />
used cook<strong>in</strong>g oil <strong>in</strong> the form <strong>of</strong> an acid catalyst<br />
add<strong>in</strong>g before transesterification is conducted. <strong>The</strong><br />
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January 24, 2009<br />
purpose <strong>of</strong> the treatment is to reduce free fatty acids<br />
concentration <strong>in</strong> used palm cook<strong>in</strong>g oil through<br />
esterification reaction. In the esterification reaction<br />
step,usually a catalyst homogen such as sulfuric acid<br />
was used. <strong>The</strong> use <strong>of</strong> sulfuric acid as catalyst <strong>in</strong><br />
<strong>in</strong>dustry is not considered economical because<br />
sulfuric acid used is mixed with alcohol, so that it is<br />
difficult to separate them, moreover sulfuric acid<br />
which is conta<strong>in</strong><strong>in</strong>g sulfur can decrease the quality <strong>of</strong><br />
the biodiesel as fuel. As an alternative, a solid acid<br />
catalyst such as acidified zeolite is used [13-19].<br />
Materials And Methods<br />
Materials<br />
<strong>The</strong> natural zeolite was supplied by<br />
PT.An<strong>in</strong>dya Divisi Pertambangan, Yogyakarta.<br />
Technical grade Sodium hydroxide, methanol and<br />
sulfuric acid were used as received. Aquabidest as a<br />
dispersion media was purchased from Lab.<strong>of</strong> Physical<br />
Chemistry, Gadjah Mada University. Used cook<strong>in</strong>g<br />
palm oil was purchased from CV.Kembang<br />
Nusantara,Yogyakarta.<br />
Instrumentations<br />
<strong>The</strong> X-Ray diffraction (XRD) patterns were<br />
obta<strong>in</strong>ed on Shimadzu PW3710 BASED<br />
diffractometer equipped with Shimadzu X-ray<br />
generator, us<strong>in</strong>g CuKα radiation. <strong>The</strong> scann<strong>in</strong>g (2θ)<br />
range was from 2 to 40 o and the scann<strong>in</strong>g rate was<br />
5 o /m<strong>in</strong>. FTIR spectra was obta<strong>in</strong>ed from Shimadzu<br />
FTIR-8201 PC. Concentration <strong>of</strong> biodiesel was<br />
determ<strong>in</strong>ed us<strong>in</strong>g 1 H-NMR (60 MHz) and Gas<br />
Chromatography (HP 5890 Shimadzu), meanwhile<br />
components <strong>of</strong> biodiesel were determ<strong>in</strong>ed us<strong>in</strong>g Gas<br />
Chromatography–Mass Spectrometer (Shimadzu).<br />
Synthesis and Characterization <strong>of</strong> H-<strong>Zeolite</strong><br />
<strong>The</strong> study was <strong>in</strong>itiated with natural zeolite<br />
activation us<strong>in</strong>g technical sulfuric acid. One hundered<br />
gram natural zeolite with dimension <strong>of</strong> 250 mesh was<br />
dispersed <strong>in</strong>to 1,6M technical grade sulfuric acid. <strong>The</strong><br />
dispersion was stirred and then filtered. <strong>The</strong> solid<br />
phase was heated at 120 o C for 5 hours. <strong>The</strong> product<br />
was labeled as H-zeolite. After activation the Hzeolite<br />
was characterized its acidity by gravimetric<br />
method, its structure by X-ray diffractometry, and<br />
FT-IR. To calculate methyl esters content we used<br />
proton-NMR data and equation 1.<br />
C<br />
ME<br />
= 100%<br />
×<br />
5×<br />
I<br />
ME<br />
( 5×<br />
I ME ) + ( 9×<br />
ITAG<br />
)<br />
(1)<br />
Where<br />
CME<br />
IME<br />
ITAG<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
=conversion <strong>of</strong> methyl ester (%)<br />
=<strong>in</strong>tegrtion value <strong>of</strong> methyl ester peaks (%)<br />
=<strong>in</strong>tegration value <strong>of</strong> triasylglicerol (%)<br />
Synthesis <strong>of</strong> Biodiesel<br />
<strong>The</strong> H-zeolite which was used <strong>in</strong> the process<br />
was varied its weight towards (oil + methanol) weight<br />
i.e. 1.50%; 3.50%; 5.50% and 6.50%. As a<br />
comparison, pretreatment <strong>of</strong> used cook<strong>in</strong>g palm oil<br />
also has been done over 1.50 % sulfuric acid. After<br />
pretreatment, the oil was separated from methanol<br />
and H-zeolite, the reaction was cont<strong>in</strong>ued by<br />
transesterify<strong>in</strong>g the oil with methanol us<strong>in</strong>g NaOH as<br />
catalyst. <strong>The</strong> transesterification product then was<br />
labeled as biodiesel. Both esterification and<br />
transesterification process were carried out <strong>in</strong> a<br />
ste<strong>in</strong>lessteel biodiesel reactor at temperature <strong>of</strong> 70 o C<br />
for 2 hours (Fig.1). <strong>The</strong> composition <strong>of</strong> the biodiesel<br />
was analyzed us<strong>in</strong>g Gas chromatography–Mass<br />
Spectroscopy (GC-MS), 1 H-NMR and their physical<br />
properties were analyzed us<strong>in</strong>g ASTM analysis<br />
methods.<br />
Figure.1 Biodiesel reactor with capacity <strong>of</strong> 10 L to<br />
prepare biodiesel from used cook<strong>in</strong>g plm oil<br />
Results And Discuccion<br />
Preparation <strong>of</strong> H-<strong>Zeolite</strong><br />
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January 24, 2009<br />
<strong>The</strong> study was <strong>in</strong>itiated with natural zeolite<br />
activation us<strong>in</strong>g technical sulfuric acid. After<br />
activation the zeolite was characterized its acidity by<br />
gravimetric method, its structure by X-ray<br />
diffractometry, and FT-IR. From X-ray analysis result<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
could be concluded that the acid activation resulted <strong>in</strong><br />
no destruction <strong>of</strong> the natural zeolite structure<br />
significantly. It can be seen clearly from the reflexes<br />
<strong>of</strong> H-zeolite <strong>in</strong> its difractogram which almost all <strong>of</strong><br />
the reflexes still exist after acid activation (Fig.2)<br />
Figure. 2 Difractogram <strong>of</strong> natural zeolite (above) and H-zeolit (below)<br />
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January 24, 2009<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
Figure 3. FT-IR Spectra <strong>of</strong> H-zeolite (above) and natural zeolite (below)<br />
Infra red analysis result also supported the<br />
X-ray analysis data. <strong>The</strong>re was no <strong>in</strong>dication that acid<br />
activation caused a significant distruction <strong>of</strong> zeolite<br />
structure. After activation all importance vibrationts<br />
<strong>of</strong> the zeolite still appeared <strong>in</strong> H-zeolite spectra<br />
(Fig.3).<br />
Gravimetry analysis <strong>in</strong>dicated that acid<br />
activation can cause the <strong>in</strong>creas<strong>in</strong>g <strong>of</strong> total acidity <strong>of</strong><br />
the clay <strong>in</strong> some extent (from 0.02980 mmol<br />
NH3/gram to be 0.03125 mmol NH3/gram) . <strong>The</strong><br />
<strong>in</strong>crease <strong>of</strong> the acid uptake <strong>in</strong>dicated that the surface<br />
area and adsorption sites <strong>of</strong> the H-zeolite was higher<br />
than natural unmodified zeolite, <strong>The</strong>refore, it is<br />
expected that H-zeolite has catalytic properties higher<br />
than natural unmodified zeolite.<br />
Synthesis <strong>of</strong> Biodiesel<br />
Biodiesel reactor with capacity <strong>of</strong> 10 L can<br />
used for biodiesel synthesis from used cook<strong>in</strong>g palm<br />
oil. <strong>The</strong> product and the used cook<strong>in</strong>g palm oil are<br />
displayed <strong>in</strong> Fig.4. <strong>The</strong> color <strong>of</strong> obta<strong>in</strong>ed biodiesel<br />
was bright yellow meanwhile used cook<strong>in</strong>g palm oil<br />
was dark brown. <strong>The</strong> characterization result <strong>in</strong>dicated<br />
that addition <strong>of</strong> H-zeolite <strong>in</strong> esterfication could<br />
decrease its free fatty acid content from 4.166% to<br />
1.58% .<br />
Figure 4. Used cook<strong>in</strong>g palm oil (left) and biodiesel<br />
(right)<br />
To determ<strong>in</strong>e the methyl esters concentration<br />
<strong>in</strong> product we used proton-NMR analysis method.<br />
Analysis results (Fig.3, Fig.4.and Fig.5) exhibited that<br />
esterification and transesterification resulted <strong>in</strong> the<br />
formation <strong>of</strong> biodiesel which <strong>in</strong>dicated by appear<strong>in</strong>g a<br />
sharp peak around 3,7 ppm at its spectrogram (Fig.<br />
7). Calculation us<strong>in</strong>g equation 1 showed that the<br />
<strong>in</strong>creas<strong>in</strong>g <strong>of</strong> H-zeolite would <strong>in</strong>crease the biodiesel<br />
conversion. <strong>The</strong> highest conversion <strong>of</strong> biodiesel was<br />
98,41% achieved by addition <strong>of</strong> H-zeolite <strong>of</strong> 5.5%<br />
(w/w).<br />
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Figure. 5. Proton-NMR spectra <strong>of</strong> used cook<strong>in</strong>g palm oil<br />
Fig. 6. Proton-NMR spectra <strong>of</strong> esterification product<br />
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<strong>The</strong> result <strong>of</strong> GC and GC-MS analysis<br />
showed that ma<strong>in</strong> components <strong>of</strong> biodiesel were<br />
mixture <strong>of</strong> methyl esters with methyl oleic as the<br />
<strong>The</strong> existence <strong>of</strong> methyl palmitic was <strong>in</strong>dicated by the<br />
appearance <strong>of</strong> fragment with m/z= 270, 239 and 74<br />
(Fig.9). <strong>The</strong> appearance <strong>of</strong> fragments with m/z = 294,<br />
263, 81,55 and 41 was considered due to methyl<br />
l<strong>in</strong>oleaic (Fig. 10). Fragments with m/z = 296, 266,<br />
Fig. 7. Proton-NMR spectra <strong>of</strong> biodiesel<br />
Figure.8 Chromatogram <strong>of</strong> mixed methyl esters<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
major compound ca. 40.66% (Fig. 8-12). Other<br />
componets were methyl palmitic (34,37%), l<strong>in</strong>oleic<br />
(13,12%) and stearic (6,84%) (Fig. 9-12).<br />
264, 74, 69, 55 and 41 was caused by methyl oleic<br />
(Fig.11). F<strong>in</strong>ally, the methyl stearic appeared with<br />
m/z = 87, 101, 115, 129, 143, 157, 171, 185, 199,<br />
213, 227, 241, and 225 (Fig.12).<br />
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C 3H 6O 2<br />
m/z = 74 O<br />
C 16H 31O<br />
m/z = 239<br />
Figure 9. Mass spectra and structure <strong>of</strong> methyl palmitic<br />
C 18H 30O<br />
m/z = 262<br />
Figure 10. Mass spectra and structure <strong>of</strong> methyl l<strong>in</strong>oleic<br />
C 18H 32O<br />
m/z = 264<br />
Figure 11. Mass spectra and structure <strong>of</strong> methyl oleic<br />
OCH 3<br />
OCH 3<br />
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O<br />
O<br />
OCH 3
<strong>The</strong> First International Sem<strong>in</strong>ar on Science and Technology<br />
January 24, 2009<br />
Biodiesel produced from the above metioned<br />
process are further tested their physicochemical<br />
properties us<strong>in</strong>g ASTM method and are compared<br />
with the specification <strong>of</strong> ASTM biodiesel (Table 1).<br />
Biodiesel resulted from esterification with H-zeolite<br />
and transesterification proved to fulfil 8 criteria<br />
stipulated for diesel oil, which <strong>in</strong>clude viscosity,<br />
density, flash po<strong>in</strong>t, water content, Conradson carbon<br />
residue, fuel value and specific density. Viscosity <strong>of</strong><br />
biodisel is related to specific density <strong>in</strong> which the<br />
higher the viscosity was, the greater the specific<br />
density would be. Biodiesel with high specific density<br />
will be difficult to flow so that it will slow down the<br />
ignition process. Biodiesel viscosity from used<br />
cook<strong>in</strong>g palm oil had lower viscosity than used oil,<br />
and if it is used as fuel for diesel eng<strong>in</strong>e, the result <strong>of</strong><br />
<strong>in</strong>jection <strong>in</strong> ignition chamber will easily form nebula<br />
which facilitate ignition.<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
C 3H 6O 2<br />
m/z = 74 O<br />
C 18H 35O<br />
m/z = 267<br />
Figure 12. Mass spectra and structure <strong>of</strong> methyl stearic<br />
OCH 3<br />
Flash po<strong>in</strong>t <strong>of</strong> biodiesel from used cook<strong>in</strong>g<br />
palm oil is relatively very high. <strong>The</strong> high flash po<strong>in</strong>t<br />
make biodiesel easy for stor<strong>in</strong>g. <strong>The</strong> biodiesel can be<br />
saved easily and safely <strong>in</strong> tropical areas. If flash po<strong>in</strong>t<br />
<strong>of</strong> the biodiesel was lower, the biodiesel will be easily<br />
flammable <strong>in</strong> stor<strong>in</strong>g. Biodiesel from used cook<strong>in</strong>g<br />
palm oil is considered to have high pour po<strong>in</strong>t. <strong>The</strong><br />
high pour po<strong>in</strong>t cause the diesel eng<strong>in</strong>e to stuck <strong>in</strong><br />
lower temperature so that it is not suitable for use <strong>in</strong><br />
sub tropical areas.<br />
<strong>The</strong> comparison between specification <strong>of</strong><br />
biodiesel produced <strong>in</strong> the research with specification<br />
<strong>of</strong> diesel oil for <strong>in</strong>dustry and automotive was shown<br />
<strong>in</strong> Table 1. Of the five criteria presented, our<br />
biodiesel fulfil the requirements for be<strong>in</strong>g alternative<br />
fuel for diesel oil for <strong>in</strong>dustry and auttomotive.<br />
Table 1. Comparison between physical characteristic <strong>of</strong> biodiesel with diesel oil for <strong>in</strong>dustry<br />
and automotive diesel oil.<br />
Parameter<br />
Used cook<strong>in</strong>g<br />
palm oil<br />
Automotive diesel<br />
oil *)<br />
Industry<br />
diesel oil *)<br />
Specific density 60/60 o F 0,9124 0,820-0,870 0,840-0,920<br />
Brutto fuel value (GHV),<br />
BTU/lb **) 19173,25 19031-19220 18842-19145<br />
Netto fuel value (NHV),BTU/lb **)<br />
17423,52 17856-17977 17735-17929<br />
K<strong>in</strong>ematic viscosity 40 o C 40,37 2,0-5,0 7,000<br />
Pour po<strong>in</strong>t, o F<br />
39,2 65,000 65,000<br />
Flash po<strong>in</strong>t, o F<br />
341,6 M<strong>in</strong> 150 M<strong>in</strong> 150<br />
Conradson carbon residue % 0,391 Max 0,100 Max 1,000<br />
Water content, % vol. 0,12 Max 0,05 Max 0,05<br />
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January 24, 2009<br />
Conclusions<br />
<strong>The</strong> research results showed that activation<br />
resulted <strong>in</strong> no destruction <strong>of</strong> zeolite structure and<br />
<strong>in</strong>creased its acidity. Biodiesel reactor can used for<br />
biodiesel synthesis from used cook<strong>in</strong>g palm oil.<br />
<strong>Addition</strong> <strong>of</strong> H-zeolite <strong>in</strong> esterfication could decrease<br />
its free fatty acid content. Increas<strong>in</strong>g <strong>of</strong> H-zeolite<br />
would <strong>in</strong>crease the biodiesel conversion. <strong>The</strong> highest<br />
conversion <strong>of</strong> biodiesel was 98,41% achieved by<br />
addition <strong>of</strong> H-zeolite <strong>of</strong> 5.5% (w/w). <strong>The</strong> result <strong>of</strong><br />
GC-MS analysis showed that ma<strong>in</strong> components <strong>of</strong><br />
biodiesel were mixture <strong>of</strong> methyl esters with methyl<br />
oleic as the major compound (40.66%). Based on the<br />
ASTM analysis data, the obta<strong>in</strong>ed biodiesel<br />
specification was <strong>in</strong> agreement with diesel fuel<br />
specification for automotive.<br />
References<br />
1. Arrowsmith, C.J., J. Ross, 1945, Treat<strong>in</strong>g<br />
Fatty Materials, US Patent , 2,383,580.<br />
2. Canakei, M., dan Van Gerpen, J., 2003, A<br />
Pilot Plant to Produce Biodiesel from High<br />
Free Fatty Acids Feedstocks, Am. Soc.<br />
Agric, Eng., 46, 945-954.<br />
3. Demirbas, A., 2003, Biodiesel Fuels from<br />
Vegetable Oils via Catalytic and Non-<br />
Catalytic Supercritical Alcohol<br />
Transesterifications and Other Methods: A<br />
Survey, J. Tur. Chem. Educ., 44, 2093-2109.<br />
4. Freedman, B., 1984, Variables Affect<strong>in</strong>g the<br />
Yield <strong>of</strong> Fatty Aster from Transesterified<br />
Vegetables Oil, J: Am. Oil Chem, 10,61.<br />
5. Hamdan, H., 1992, Introduction to <strong>Zeolite</strong>s:<br />
Synthesis, Characterization, and<br />
Modification, Universiti Teknologi<br />
Malaysia, Kuala Lumpur.<br />
6. Hanna, A.M., dan Ma, F., 1999, Biodiesel<br />
Production Areview, J., Agric & Natural, 70,<br />
1-15.<br />
7. Hardjono, A., 2001, Teknologi M<strong>in</strong>yak Bumi,<br />
Edisi pertama, Gadjah Mada University<br />
Press, Jogjakarta.<br />
8. Hidayat, D, 2008, Pengaruh katalis H-Zeolit<br />
pada Proses Pembuatan Biodiesel dari<br />
M<strong>in</strong>yak Jelantah kelapa Sawit Bekas<br />
Menggunakan Reaktor Biodiesel<br />
berkapasitas 10 L, Skripsi, Universitas<br />
Gadjah Mada, Jogjakarta.<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
9. Houas, A. Lachleb, H., Puzenut, E., Ksibi,<br />
M., Elaleui, E., Gullard, G., and Hermann,<br />
J.M., 2001, Photocatalytic Degradation<br />
Pathway <strong>of</strong> Methylene Blue <strong>in</strong> Water, Appl.<br />
Catal. B: Environmental 30. 145-157.<br />
10. Keim, G.I., 1945, Treat<strong>in</strong>g Fats and Fatty<br />
Oils U.S., Patent, 383.<br />
11. Knothe, G., 2000, Monitor<strong>in</strong>g a Progress<strong>in</strong>g<br />
Transesterification Reaction by Fiber-Optic<br />
Near Infrared Spectroscopy with correlation<br />
to H Nuclear Magnetic Resonance<br />
Spectroscopy, Jpn. Am. Oil. Chem. Soc., 77,<br />
J 9483, 489-493.<br />
12. Mastutik, D., 2006, Transesterifikasi M<strong>in</strong>yak<br />
Jelantah Kelapa Sawit menjadi Biodiesel<br />
Menggunakan Zeolit-Y Melalui Proses<br />
Esterifikasi, Tesis, Universitas Gadjah<br />
Mada, Jogjakarta.<br />
13. Nye, M.J., dan southwell, P.H., 1983, Esters<br />
from Repeseed Oil as Diesel Fuel In: Proc.<br />
Vegetable Oil as Fuel Sem<strong>in</strong>ar III, Pcoria:<br />
Northern Agricultural Energy Center, 78-83.<br />
14. Oudejans, J.C., 1984, <strong>Zeolite</strong> Catalysis <strong>in</strong><br />
Some Organic Reactions, Chemical<br />
Research (SON), Holland.<br />
15. Patzer, R., dan Norris, M., 2002, Evaluated<br />
Biodiesel Made from Waste Fats and Oils,<br />
F<strong>in</strong>al report, Agriculture Utilization<br />
Research Institute, University <strong>of</strong> M<strong>in</strong>nesota,<br />
M<strong>in</strong>nesota.<br />
16. Saefud<strong>in</strong>, A., 2005, S<strong>in</strong>tesis Biodiesel<br />
Melalui reaksi esterifikasi M<strong>in</strong>yak Jelantah<br />
Dengan Katalis Montmorillonit Teraktivasi<br />
Asam Sulfat Yang Dilanjutkan Dengan<br />
Reaksi Transesterifikasi Terkatalisis NaOH,<br />
Skripsi, Universitas Gadjah Mada,<br />
Jogjakarta.<br />
17. Setyawan, D.A., 2001, Pengaruh Waktu dan<br />
temperatur Hidrotermal terhadap<br />
Dealum<strong>in</strong>asi dan Keasaman Zeolit Alam<br />
Aktif, Skripsi, FMIPA UGM, Yogyakarta.<br />
18. Van, Gerpen, J., Shanks, B., Pruszko, R.,<br />
2004, Biodiesel Production Technology,<br />
National Renewable Energy Laboratory,<br />
Collorado.<br />
19. Zappi, M., Hernandez, M., Spark, D., Horne,<br />
J., Brough, M., 2003, A Review <strong>of</strong> the<br />
Eng<strong>in</strong>eer<strong>in</strong>g Aspects <strong>of</strong> the Biodiesel<br />
Industry, MSU Environmental Technology<br />
Research and Applications Laboratory Dave<br />
C. Swalm School <strong>of</strong> Chemical Eng<strong>in</strong>eer<strong>in</strong>g<br />
Mississippi State University, Mississippi.<br />
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Preparation <strong>of</strong> Solid Acid Catalysts from Bentonite and <strong>The</strong>ir Catalytic<br />
Activities for <strong>The</strong> <strong>Esterification</strong> <strong>of</strong> Jatropha curcas Seed Oil<br />
Novizar Nazir 1,3 , Djumali Mangunwidjaja 2 , Mohd. Ambar Yarmo 3 Jumat Salimon 3<br />
and Nazarudd<strong>in</strong> Ramli 3<br />
1 Faculty <strong>of</strong> Agricultural Technology, University <strong>of</strong> Andalas Padang, Indonesia<br />
Kampus Limau Manis. Padang 25163, Indonesia<br />
Telp. +62 751 72772- E-mail address: nazir_novizar@yahoo.com<br />
2 Department <strong>of</strong> Agro<strong>in</strong>dustrial Technology, Institut Pertanian Bogor<br />
Kampus IPB Darmaga, Bogor, Indonesia<br />
3 School <strong>of</strong> Chemical Science and Food Technology, FST UKM, Malaysia<br />
43600 UKM, Bangi, Selangor Darul Ehsan, Malaysia<br />
Abstract<br />
<strong>The</strong> esterification reaction <strong>of</strong> Jatropha curcas seed oil with methanol to remove free fatty acid (FFA)<br />
for biodiesel production was conducted us<strong>in</strong>g various bentonite catalysts. Solid acid catalysts from<br />
bentonite were prepared by aqueous impregnation technique. 5.3 M HCl and 40% by mass <strong>of</strong> H 2SO 4<br />
were supported on bentonite by aqueous impregnation, washed with deionized water till Cl -1 and SO 4 -<br />
2 ions were not detected, dried overnight and calc<strong>in</strong>ated at 500 o C for three hours. Catalysts was<br />
characterized by XRD, nitrogen adsorption-desorption, and pyrid<strong>in</strong>e adsorption FTIR. Five catalysts<br />
used <strong>in</strong> esterification reactions <strong>of</strong> Jatropha curcas seed oil with methanol were compared: (A) nonactivated<br />
bentonite; (B) HCl 5.3 M-activated bentonite; (C) HCl 5.3 M-activated bentonite and<br />
calc<strong>in</strong>ated at 500 o C (D) H 2SO 4 40%-activated bentonite; (E) H 2SO 4 40%-activated bentonite and<br />
calc<strong>in</strong>ated at 500 o C. <strong>The</strong> effects structure properties <strong>of</strong> bentonite catalysts were discussed relat<strong>in</strong>g<br />
to the conversion <strong>of</strong> the FFA.<br />
Keywords: Jatropha curcas, solid acid catalyst, esterification, acid-activated bentonite, FFA,<br />
biodiesel<br />
Introduction<br />
With the <strong>in</strong>creas<strong>in</strong>g price <strong>of</strong> petroleum and<br />
environmental concerns over pollution caused by the<br />
<strong>in</strong>ternal combustion gases, alternative fuels have been<br />
developed [1, 2]. Biodiesel is considered as one <strong>of</strong> the<br />
alternative fuels for diesel eng<strong>in</strong>es become<br />
<strong>in</strong>creas<strong>in</strong>gly important [3].<br />
Biodiesel is def<strong>in</strong>ed as the mono alkyl esters <strong>of</strong><br />
long cha<strong>in</strong> fatty acids derived from renewable<br />
feedstocks, such as vegetable oil or animal fats, use <strong>in</strong><br />
compression ignition eng<strong>in</strong>e [4]. It is a clean-burn<strong>in</strong>g<br />
fuel, biodegradable, nontoxic and has low emission<br />
pr<strong>of</strong>iles and so is environmentally beneficial. Use <strong>of</strong><br />
biodiesel has the potential to reduce the level <strong>of</strong><br />
pollutants and <strong>of</strong> potential carc<strong>in</strong>ogens [5,6,7].<br />
In biodiesel production, the use <strong>of</strong> edible oils will<br />
compete with the food product. Consequently, the<br />
use <strong>of</strong> non-edible oil as alternative source will be<br />
important. Among several non-edible oil seed species<br />
could be utilized as source for oil production, J.<br />
curcas which grows <strong>in</strong> tropical and sub-tropical<br />
climates accross develop<strong>in</strong>g world is a multipurpose<br />
species with many attributes and potentials [8,9]<br />
However, the relatively higher amounts <strong>of</strong> free fatty<br />
acids (FFA) and water <strong>in</strong> this feedstock results <strong>in</strong> the<br />
production <strong>of</strong> soap <strong>in</strong> the presence <strong>of</strong> alkali catalyst.<br />
Dur<strong>in</strong>g alkal<strong>in</strong>e-catalyzed transesterification, high<br />
content FFA will react with alkali catalysts to produce<br />
soaps which will <strong>in</strong>hibit the transesterification for<br />
biodiesel production. Furthermore, the large amount<br />
<strong>of</strong> soap can gel and also prevent the separation <strong>of</strong> the<br />
glycerol from the ester [5]. Acid-catalyzed<br />
transesterification, despite its <strong>in</strong>sensitivity to FFA <strong>in</strong><br />
the feedstock, has been largely ignored ma<strong>in</strong>ly<br />
because <strong>of</strong> its relatively slower reaction rate [6].<br />
<strong>The</strong>refore a process comb<strong>in</strong><strong>in</strong>g pretreatment with<br />
alkal<strong>in</strong>e-catalyzed transesterification for feedstocks<br />
hav<strong>in</strong>g high FFA content was <strong>in</strong>vestigated by many<br />
authors [10,11,12,3].<br />
Acid-catalyzed esterification <strong>of</strong> high FFA content<br />
vegetable oils is a typical method <strong>of</strong> biodiesel<br />
production due to high reaction speed and high yield<br />
[13]. Some raw feedstocks with high FFA such as<br />
yellow and brown grease [10], rubber seed oil [11]<br />
mahua oil [14], waste cook<strong>in</strong>g oil [15] and jatropha<br />
oil [11] have been used to produce biodiesel with<br />
homogeneous acid-catalyzed esterification followed<br />
by transesterification us<strong>in</strong>g alkal<strong>in</strong>e catalyst.<br />
Compared with conventional liquid acid catalysts,<br />
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solid acid catalyst is more environmentally friendly<br />
[15].<br />
<strong>The</strong> present work was undertaken to <strong>in</strong>vestigate<br />
the pretreatment process for reduc<strong>in</strong>g the FFA content<br />
<strong>of</strong> jatropha oil for biodiesel production us<strong>in</strong>g various<br />
bentonite as solid acid catalyst. This paper focuses on<br />
the reaction parameters that affect the conversion <strong>of</strong><br />
FFA <strong>in</strong> crude jatropha oil by means <strong>of</strong> acid-catalyzed<br />
esterification with methanol.<br />
Materials and Methods<br />
Materials<br />
Jatropha curcas oil was hydrolic press extracted <strong>of</strong><br />
jatropha seed from Lampung, South Sumatra,<br />
Indonesia. Anhydrous methanol (MeOH), 99.8%,<br />
potassium hydroxide (KOH), sulfuric acid (H2SO4),<br />
and Hydrochloric acid (HCl), 37-38% pure were<br />
purchased from ChemAR ® .<br />
A calcium-rich bentonite (CaB) sample was<br />
obta<strong>in</strong>ed as powder from PT. Super<strong>in</strong>tend<strong>in</strong>g<br />
Company <strong>of</strong> Indonesia used <strong>in</strong> the experiments. <strong>The</strong><br />
bulk chemical analysis <strong>of</strong> the bentonite (mass %) is<br />
SiO2, 64.15; TiO2, 0.47; CrO3, 0.003; Al2O3,.70;<br />
Fe2O3, 0.10; MgO, 0.70; CaO, 0.03; , Na2O, 0.20;<br />
K2O, 0.50 and loss on ignition (LOI), 22.61.<br />
Preparation <strong>of</strong> Catalyst [16,17]<br />
Acid-activated Bentonite were prepared by<br />
aqueous impregnation technique. 5.3 M HCl and<br />
40% by mass <strong>of</strong> H2SO4 were supported on bentonite<br />
by aqueous impregnation (at 80 o C and 4 h), washed<br />
with deionized water till Cl -1 and SO4 -2 ions were not<br />
detected, dried overnight and calc<strong>in</strong>ated at 500 o C for<br />
three hours. Five catalysts for esterification <strong>of</strong><br />
jatropha oil with methanol were compared: (A)<br />
“untreated” bentonite catalyst; (B) esterification with<br />
5.3 M HCl-activated bentonite catalyst; (C)<br />
esterification with 5.3 M HCl-activated bentonite and<br />
calc<strong>in</strong>ated at 500 o C catalyst (E) esterification with<br />
40% H2SO4-activated bentonite catalyst; (F)<br />
esterification with 40% H2SO4-activated bentonite<br />
and calc<strong>in</strong>ated at 500 o C catalyst.<br />
Characterization <strong>of</strong> Catalyst<br />
<strong>The</strong> X-ray diffraction (XRD) patterns <strong>of</strong> natural<br />
and acid activated samples were recorded from<br />
random mounts prepared by glass slide method us<strong>in</strong>g<br />
a Rikagu D-Max 2200 Powder Diffractometer,<br />
operat<strong>in</strong>g at 40 kV and 30 mA, us<strong>in</strong>g Ni-filtered<br />
CuKa radiation hav<strong>in</strong>g 0.15418 nm wavelength, at a<br />
scann<strong>in</strong>g speed <strong>of</strong> 2 o 2θ m<strong>in</strong> _1 . Surface area <strong>of</strong><br />
bentonite was measured with multipo<strong>in</strong>t Brunauer,<br />
Emmett and Teller (BET) method from the<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
Quantachrome Surface Analysis Instrument<br />
(Autosorb 1-C, Boynton Beach, Florida, USA). This<br />
was done us<strong>in</strong>g nitrogen adsorption/desorption<br />
isotherms at liquid nitrogen temperature and relative<br />
pressures (P/Po) rang<strong>in</strong>g from 0.04- 0.4 where a<br />
l<strong>in</strong>ear relationship was ma<strong>in</strong>ta<strong>in</strong>ed. For acidity study,<br />
about 10 mg <strong>of</strong> the sample was pressed at 2-5 tonnes<br />
for a m<strong>in</strong>ute to obta<strong>in</strong> a 13 mm disk. <strong>The</strong> sample was<br />
<strong>in</strong>troduced <strong>in</strong> <strong>in</strong>frared cell with calcium flourite.<br />
Each sample was degases for 16 hours under vacuum<br />
at 400 °C. <strong>The</strong> <strong>in</strong>frared spectra were collected at<br />
room temperature us<strong>in</strong>g Simadzu 2000 FTIR<br />
spectrometer at 2 cm- 1 resolution. <strong>The</strong> type <strong>of</strong> acid<br />
sites were exam<strong>in</strong>ed us<strong>in</strong>g pyrid<strong>in</strong>e as probe<br />
molecule. <strong>The</strong>n pyrid<strong>in</strong>e was absorbed for 30<br />
seconds at room temperature, cont<strong>in</strong>ued by desorption<br />
at 150 °C for 1 hour. F<strong>in</strong>ally, the sample was<br />
desorpted at 400 °C for 1 hour.<br />
<strong>Esterification</strong> process catalyzed by sulfuric acid<br />
<strong>Esterification</strong> was conducted <strong>in</strong> a 250 ml threeneck<br />
flask. <strong>The</strong> flask was equipped with a<br />
mechanical agitator and a reflux condenser, and<br />
heated with a water bath to control the reaction<br />
temperature (60 o C). In the experiments, flasks loaded<br />
with Jatropha oil samples were firstly heated to the<br />
designated temperature. This was followed by the<br />
addition <strong>of</strong> the methanol (methanol : oil ratio, 0.28<br />
v/v) and sulfuric acid (1.34%) mixture before turn<strong>in</strong>g<br />
on the agitator, mark<strong>in</strong>g the start <strong>of</strong> the esterification<br />
reaction.<br />
<strong>The</strong> application solid acid catalyst <strong>in</strong> esterification<br />
process<br />
<strong>Esterification</strong> was conducted <strong>in</strong> a 250 ml threeneck<br />
flask. In the experiments, flasks loaded with<br />
Jatropha oil samples were firstly heated to the<br />
designated temperature (60 o C). This was followed by<br />
the addition <strong>of</strong> the methanol (methanol : oil ratio, 0.30<br />
v/v) and solid acid catalyst (5% w/v oil) mixture<br />
before turn<strong>in</strong>g on the agitator, mark<strong>in</strong>g the start <strong>of</strong> the<br />
esterification reaction. <strong>The</strong> esterification products<br />
were separated <strong>in</strong> a tap funnel to obta<strong>in</strong> the upper oil<br />
layer. After methanol recovery under vacuum at<br />
50 o C, oil layer was then washed with water several<br />
times until the pH <strong>of</strong> wash<strong>in</strong>g water was close to 7.0.<br />
<strong>The</strong> resultant esterified oil was dried by anhydrous<br />
magnesium sulfate before acid value analysis.<strong>The</strong><br />
convertion <strong>of</strong> FFA was def<strong>in</strong>ed as the fraction <strong>of</strong> the<br />
FFA removed. <strong>The</strong> convertion <strong>of</strong> FFA (xFFA) was<br />
determ<strong>in</strong>ed from acid number ration us<strong>in</strong>g below<br />
equation [15]:<br />
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Where ai is the <strong>in</strong>itial acid number <strong>of</strong> the reactant<br />
and at is the acid number <strong>of</strong> product at ‘t’ time.<br />
Alkali catalysed transesterification <strong>of</strong> jatropha oil<br />
<strong>The</strong> collected oil layer was transferred to 250 ml<br />
round bottom, 0.1g v/v methanol and 3.5 w/v +acid<br />
number <strong>of</strong> KOH were added. <strong>The</strong> mixture was<br />
reacted for 24 m<strong>in</strong>utes at 65 o C. <strong>The</strong> mixture was left<br />
to settle to separate <strong>in</strong>to two layers. <strong>The</strong> upper layer<br />
was the FAME (crude biodiesel).<br />
Results and Discussion<br />
Characterization <strong>of</strong> Catalyst<br />
Fig. 1 shows changes <strong>in</strong> <strong>in</strong>tensity and width <strong>of</strong><br />
the 001 peak, which <strong>in</strong>dicate that the crystall<strong>in</strong>ity <strong>of</strong><br />
the bentonite is considerably affected by acid<br />
activation an calc<strong>in</strong>ation. <strong>The</strong> variation <strong>of</strong> relative<br />
<strong>in</strong>tensity (I / I0) and full width at half-maximum<br />
(FWHM) peak height <strong>of</strong> the XRD peak for bentonites<br />
represent the <strong>in</strong>tensities for the natural and acidactivated<br />
bentonite samples, respectively. <strong>The</strong><br />
decrease <strong>in</strong> I / I0 and <strong>in</strong>crease <strong>in</strong> FWHM on the 001<br />
XRD peak show that the crystall<strong>in</strong>ity <strong>of</strong> bentonite<br />
decreases by <strong>in</strong>creas<strong>in</strong>g <strong>in</strong> acid [17].<br />
2500<br />
2000<br />
1500<br />
1000<br />
500<br />
0<br />
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HCl 5.3. M non-calic<strong>in</strong>ated<br />
0<br />
0 5 10 15 20 25 30 35<br />
o2θ Fig. 1. <strong>The</strong> XRD patterns <strong>of</strong> the natural and some <strong>of</strong><br />
the acid-activated bentonite (S: smectite, I:<br />
illite, FWHM: full width at half maximum<br />
peak height).<br />
<strong>The</strong> total pore volume <strong>of</strong> samples is measured by<br />
condensation <strong>of</strong> N2 adsorbate at P/Po 0.95 <strong>in</strong> the pores<br />
<strong>of</strong> diameter
<strong>The</strong> First International Sem<strong>in</strong>ar on Science and Technology<br />
January 24, 2009<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
[a] [b]<br />
Fig. 2. FTIR spectra <strong>of</strong> samples (a) after pyrid<strong>in</strong>e adsorption at room temperature for 30 seconds, (b) after<br />
pyrid<strong>in</strong>e adsorption and desorption at 150 o C for 1 h.<br />
Effect <strong>of</strong> esterification reaction time and type <strong>of</strong><br />
bentonite to acid value<br />
<strong>The</strong> effect <strong>of</strong> esterification reaction time and<br />
type <strong>of</strong> bentonite to acid value is shown <strong>in</strong> Fig.3.<br />
<strong>The</strong> results show that the acid value decrease<br />
significantly after 6 hours esterification. <strong>The</strong> best<br />
catalyst is HCl-activated bentonite without<br />
calc<strong>in</strong>ation with 67.70% FFA convertion after six<br />
hours reaction time. This result is lower than<br />
heterogeneous catalyzed reaction <strong>of</strong> H2SO4<br />
(91.70% FFA convertion).<br />
Fig.3. Effect <strong>of</strong> esterification reaction time and type <strong>of</strong> bentonite to acid value <strong>of</strong> esterified oil<br />
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Effect <strong>of</strong> esterification reaction time to convertion<br />
<strong>of</strong> FFA and acid value<br />
Accord<strong>in</strong>g to Lu et al [18], FFA convertion<br />
will <strong>in</strong>crease with the <strong>in</strong>creas<strong>in</strong>g <strong>of</strong> time,<br />
temperature and ratio methanol to oil. In this<br />
experiment we <strong>in</strong>crease the reaction temperature<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
from 60 o C to 65 o C and methanol to oil ratio from<br />
0.30 (v/v) to 0.40 (v/v) us<strong>in</strong>g catalyst B. <strong>The</strong><br />
convertion <strong>of</strong> FFA and acid value <strong>of</strong> esterified oil is<br />
shown <strong>in</strong> Fig.4. <strong>The</strong> result shows that the<br />
convertion <strong>of</strong> FFA <strong>in</strong>crease from 67.70% to 81.7%<br />
Fig. 4. Effect <strong>of</strong> esterification reaction time to convertion <strong>of</strong> FFA and acid value <strong>of</strong> esterified oil<br />
Alkali catalysed transesterification <strong>of</strong> jatropha oil<br />
In this work, the lowest acid value <strong>of</strong> esterified<br />
jatropha oil was 2.32 mg KOH/g. In fact, the alkali<br />
catalyzed transesterification <strong>of</strong> jatropha oil could<br />
work, even if the FFA content was over 1% [19].<br />
<strong>The</strong> reaction <strong>of</strong> jatropha oil with methanol was easy<br />
to perform. <strong>The</strong> bottom layer <strong>of</strong> glycerol was<br />
obvious after 24 m<strong>in</strong>utes reaction time [12].<br />
Chemical properties <strong>of</strong> jatropha biodiesel obta<strong>in</strong>ed<br />
from the FFA removal by esterefication <strong>of</strong> FFA <strong>in</strong><br />
jatropha oil with H2SO4 (at 60 o C and 88 m<strong>in</strong>utes<br />
reaction time) and HCl-activated bentonite (at 70<br />
o C and 6 hours reaction time) is shown <strong>in</strong> Table 2.<br />
Table 2. Chemical properties <strong>of</strong> jatropha biodiesel obta<strong>in</strong>ed from the FFA removal by esterefication <strong>of</strong> FFA <strong>in</strong><br />
jatropha oil with H2SO4 (at 60 o C and 88 m<strong>in</strong>utes reaction time) and HCl-activated bentonite (at 70<br />
o C and 6 hours reaction time)<br />
Conclusion<br />
Property Product after the<br />
reaction on H2SO4<br />
Product after the<br />
reaction on HClactivated<br />
bentonite<br />
Density (kg/m 2 ) 0,87 0,87<br />
K<strong>in</strong>ematic viscosity (mm/s 2 ) 1,73 1,74<br />
Free Fatty Acid (mg KOH/g oil) 0,24 0,47<br />
Based on the result <strong>of</strong> this study, it can concluded<br />
that:<br />
1. Acid activation and calc<strong>in</strong>ation on bentonite<br />
affect the cristal<strong>in</strong>ity, surface area, pore<br />
volume and acidity properties <strong>of</strong> bentonite.<br />
2. HCl-activated bentonite without calc<strong>in</strong>ation has<br />
potential to be solid acid catalyst for<br />
esterification <strong>of</strong> jatropha oil. Convertion <strong>of</strong><br />
FFA reached 81.7% when parameters are as<br />
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follows: reaction time 6 h, amount <strong>of</strong> catalyst<br />
5%, ratio methanol oil 0.4 v/v and reaction<br />
time 65 o C.<br />
3. HCl-activated bentonite as act<strong>in</strong>g as<br />
heteregeneous acid catalyst shows good<br />
activity to catalyze the esterification <strong>of</strong><br />
jatropha oil and methanol. Compared with<br />
sulfuric acid, this catalyst is environmentally<br />
friendly, easy to separate from the system,<br />
reusable and does not need high cost<br />
equipment for anti-corrosion<br />
Acknowledgements<br />
<strong>The</strong> authors thank University Kebangsaan Malaysia<br />
for all facilities and support<strong>in</strong>g this study by the<br />
Research University Grant UKM-oup-nbt-29-<br />
151/2008.<br />
References<br />
[1] M. Fangrui, A.H. Milford (1999):<br />
Biodiesel production: a review. Bioresour.<br />
Technol. 70, 1–15.<br />
[2] J.M. Marchetti, V.U. Miguel, A.F. Errazu<br />
(2007). Possible methods for biodiesel<br />
production, J. Renew. Susta<strong>in</strong>. Energy Rev. ,<br />
11, 1300–1311.<br />
[3] H.J. Berchmans,., and S. Hirata (2008).<br />
Biodiesel production from Jatropha curcas<br />
L. Seed oil with a high content <strong>of</strong> free fatty<br />
acids. Bioresour. Technol. 99, 1716-1721.<br />
[4] L.C Meher, V.D. Sagar, S.N. Naik (2006)<br />
Technical aspects <strong>of</strong> biodiesel production by<br />
transesterification—a review, J.Renew.<br />
Susta<strong>in</strong>. Energy Rev. 10, 248–268.<br />
[5] A.Demirbaş (2002). Biodiesel from<br />
vegetable oils via transesterification <strong>in</strong><br />
supercritical methanol, Energy Conserv.<br />
Manage. 43, 2349–2356.<br />
[6] Y. Zhang, M.A. Dubè, D.D. McLean, M.<br />
Kates (2003). Biodiesel production from<br />
waste cook<strong>in</strong>g oil: 1. Process design and<br />
technological assessment. Bioresour. Techn.<br />
, 89, 1-16.<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
Proceed<strong>in</strong>g Book 447
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January 24, 2009<br />
Synthesis and Characterization <strong>of</strong> Al2O3/TS-1<br />
Rivone Septa Wijayanti, Didik Prasetyoko<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
Laboratorium <strong>of</strong> Inorganic Chemistry, Department <strong>of</strong> Chemistry, Faculty <strong>of</strong> Mathematic and Sciences, Institut<br />
Teknologi Sepuluh Nopember (<strong>ITS</strong>), Surabaya, Indonesia.<br />
1) Correspond<strong>in</strong>g author, Phone: +62-31-5943353<br />
email: didikp@chem.its.ac.id<br />
rivone_sw@yahoo.com<br />
Introduction<br />
Abstract<br />
TS-1 has good catalytic activity <strong>in</strong> reaction <strong>of</strong> selective oxidation <strong>of</strong> organic materials such as<br />
benzene and phenol us<strong>in</strong>g H 2O 2 as oxidiz<strong>in</strong>g agent. However, it has hydrophobic character that<br />
correlate with the slow rate <strong>of</strong> the reaction. Modification <strong>of</strong> catalyst us<strong>in</strong>g metal oxide result <strong>in</strong><br />
decreased <strong>of</strong> hydrophobic property, and as a sonsequence the rate <strong>of</strong> the reaction will be<br />
<strong>in</strong>creased. In this paper, TS-1 was modified by Al2O 3 us<strong>in</strong>g impregnation method. <strong>The</strong> solid<br />
were characterized by X-ray diffraction, <strong>in</strong>frared spectroscopy, and hydrophilicity techniques.<br />
Hydrophilicity test <strong>of</strong> Al2O 3/TS-1 was carried out us<strong>in</strong>g the mixture <strong>of</strong> xylene and water. <strong>The</strong><br />
impregnated catalysts Al 2O 3/TS-1 show partially hydrophilic property. Al 2O 3/TS-1 catalyst with<br />
4%wt load<strong>in</strong>g demonstrated fastest submerged time at water as compare to other samples. <strong>The</strong><br />
addition <strong>of</strong> Al2O 3 <strong>in</strong>creased hydrophilicity <strong>of</strong> TS-1 which is <strong>in</strong>dicated by the results <strong>of</strong><br />
hydrophilicity test.<br />
Key words: catalyst, Al2O 3/TS-1, hydrophilic<br />
<strong>The</strong> synthesis <strong>of</strong> titanium silicalite (TS-<br />
1) was first reported by Taramasso et al. [1] <strong>in</strong><br />
1983. Titanium silicalite-1 (TS-1), a MFI-type<br />
titanosilicate, has been used as a highly-efficient,<br />
heterogeneous catalyst for selective oxidation <strong>of</strong><br />
organic compounds us<strong>in</strong>g hydrogen peroxide as an<br />
oxidant. TS-1 can lessens tar product and side<br />
products which have potential as pollutant [2]. Over<br />
the last decade, the literature has reflected a high<br />
activity and selectivity <strong>of</strong> H2O2 on TS-1 as catalysts<br />
for mild oxidation reactions with H2O2 used as the<br />
oxidant, such as phenol hydroxylation, olef<strong>in</strong>s<br />
epoxidation, cyclohexanone ammoximation,<br />
alkane oxidation, oxidation <strong>of</strong> ammonia to<br />
hydroxylam<strong>in</strong>e, secondary am<strong>in</strong>es to<br />
dialkylhydroxylam<strong>in</strong>es [3].<br />
TS-1 has been commercialize <strong>in</strong><br />
hydroxylation reaction <strong>of</strong> phenol with high<br />
hydroqu<strong>in</strong>one selectivity and high H2O2 efficiency<br />
[4]. Hydroxylation reaction <strong>of</strong> phenol to produce<br />
diphenol had draws many attention s<strong>in</strong>ce 1970s,<br />
and some catalysts either homogen and also<br />
heterogeneous have been applied <strong>in</strong> this reaction<br />
[5].<br />
Reaction mechanism <strong>of</strong> phenol<br />
hydroxylation is as follows (1) TS-1 will<br />
decompose H2O2 (oxidation agent) which has<br />
hydrophilic character to form titanium-peroxo<br />
radical (<strong>in</strong>itiation step), then (2) propagation step <strong>in</strong><br />
solution [2]. This mechanism can be expla<strong>in</strong>ed via<br />
titanium-peroxo complex formation mechanism as<br />
<strong>in</strong>termediate from reaction between H2O2 and TS-1<br />
catalyst [6-10]. <strong>The</strong> rate <strong>of</strong> the form<strong>in</strong>g <strong>of</strong> titaniumperoxo<br />
depended on the rate <strong>of</strong> H2O2 reach to active<br />
site <strong>in</strong> TS-1. H2O2 is hydrophilic, that is quiet<br />
different from hydrophobic character <strong>of</strong> TS-1. [11],<br />
consequently the reaction rate <strong>of</strong> phenol<br />
hydroxylation reaction is tends to be slow [7].<br />
One <strong>of</strong> the way to <strong>in</strong>crease phenol<br />
hydroxylation reaction rate by modifieng <strong>of</strong> catalyst<br />
TS-1. Hence the existence <strong>of</strong> modified catalyst will<br />
<strong>in</strong>fluence its the character <strong>of</strong> chatalytic. <strong>The</strong><br />
property <strong>of</strong> TS-1 modified properties made become<br />
more hydrophilic character by <strong>in</strong>creas<strong>in</strong>g acidity.<br />
<strong>The</strong> addition <strong>of</strong> metal oxide is the way to <strong>in</strong>crease<br />
acidity, so the reaction rate <strong>of</strong> H2O2 with TS-1 to<br />
forms Ti-peroxo becomes more quicker. <strong>The</strong><br />
addition <strong>of</strong> acidity character may come from Lewis<br />
acidity site or Brønsted acidity site. In this research<br />
applied Al2O3/TS-1 hav<strong>in</strong>g acidity side <strong>of</strong> Lewis<br />
which is high as metal oxide added at TS-1. So that<br />
also can <strong>in</strong>crease reaction rate <strong>of</strong> H2O2 with TS-1 to<br />
forms Ti-Peroxo which <strong>in</strong> the end will yield<br />
product briefer. F<strong>in</strong>ally the reaction rate <strong>of</strong> phenol<br />
hydroxylation at Al2O3/TS-1 will be much faster<br />
and shows <strong>in</strong>creas<strong>in</strong>g <strong>of</strong> catalytic activity and<br />
selectivity higher than TS-1.<br />
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January 24, 2009<br />
Material and Methods<br />
For TS-1 (1 mol% <strong>of</strong> Ti), tetraethyl<br />
orthosilicates, TEOS (Merck, 98%) was placed <strong>in</strong>to<br />
a Teflon beaker and vigorously stirred, tetraethyl<br />
orthotitanate, TEOT (Merck, 95%) was carefully<br />
added dropwise <strong>in</strong>to this TEOS. <strong>The</strong> beaker was<br />
covered with parafilm to avoid hydrolysis. <strong>The</strong><br />
temperature <strong>of</strong> the mixture was raised to 35 o C and<br />
the reactants were mixed homogeneously for half<br />
an hour. <strong>The</strong>n the mixture was cooled to about 0 o C.<br />
<strong>The</strong> solution <strong>of</strong> TPAOH (Merck, 20% TPAOH <strong>in</strong><br />
water), which was used as template, was also<br />
cooled to 0 o C.<br />
After a few m<strong>in</strong>utes, TPAOH was added<br />
drop-wise slowly <strong>in</strong>to the mixture <strong>of</strong> TEOS and<br />
TEOT. At first, one should wait a few m<strong>in</strong>utes after<br />
addition <strong>of</strong> a few drops <strong>of</strong> TPAOH solution before<br />
more TPAOH solution is added, to avoid<br />
precipitation. Stirr<strong>in</strong>g and cool<strong>in</strong>g were cont<strong>in</strong>ued<br />
dur<strong>in</strong>g this process. After the addition <strong>of</strong> about 10<br />
mL the addition rate <strong>of</strong> TPAOH solution was<br />
<strong>in</strong>creased. When the addition <strong>of</strong> TPAOH was<br />
completed, the mixture was heated <strong>in</strong> the<br />
temperature range <strong>of</strong> 80-90 o C for about 4 h <strong>in</strong> order<br />
for the hydrolysis <strong>of</strong> TEOS and TEOT to take<br />
place. Distilled water was added to <strong>in</strong>crease the<br />
volume <strong>of</strong> the mixture, after which a clear gel was<br />
obta<strong>in</strong>ed. <strong>The</strong> gel was transferred <strong>in</strong>to autoclave<br />
and heated at 175 o C under static condition. <strong>The</strong><br />
material was recovered after 4 days <strong>of</strong><br />
hydrothermal crystallization by centrifugation and<br />
wash<strong>in</strong>g with excess distilled water. A white<br />
powder was obta<strong>in</strong>ed after dry<strong>in</strong>g <strong>in</strong> air at 100 o C<br />
overnight. <strong>The</strong> calc<strong>in</strong>ation <strong>of</strong> the sample to remove<br />
the template was carried out under static air at<br />
550 o C for 5 h with temperature rate at 1 o /m<strong>in</strong>.<br />
Samples <strong>of</strong> Al2O3/TS-1 catalyst<br />
conta<strong>in</strong><strong>in</strong>g 0,5%; 1%; 2%; and 4% were prepared<br />
by impregnation method, titanium silicalit (TS-1)<br />
was added to alumunium (III) nitrate solution<br />
which obta<strong>in</strong>ed by dissolv<strong>in</strong>g alumunium (III)<br />
nitrat. This mixture stirred at 80ºC for 3 h, dried at<br />
80-90ºC to elim<strong>in</strong>ate water, and calc<strong>in</strong>ed at 550ºC<br />
for 5 h. Catalyst TS-1 and Al2O3/TS-1 were<br />
characterized by X-ray diffraction (XRD) and<br />
<strong>in</strong>frared spectrum is recorded with Fourier-<br />
Transform Infrared (FT-IR) spectrophotometer,<br />
with KBr palette method. Hidrophilicity properties<br />
<strong>of</strong> samples was analyzed by catalyst sample powder<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
dispersion method at water phase and organic phase<br />
mixture (water and xylene). <strong>The</strong> movement <strong>of</strong><br />
catalyst sample at each phase was observed.<br />
Result and Discussion<br />
Structural and phase <strong>of</strong> samples were<br />
determ<strong>in</strong>ed by X-ray diffraction. <strong>The</strong> XRD patterns<br />
were showed <strong>in</strong> figure 1. Characteristic diffraction<br />
l<strong>in</strong>e <strong>of</strong> TS-1 is observed at 2θ = 7.88; 8.78; 23.14;<br />
23.9; 24.39; 2478°. <strong>The</strong> peak at 2θ around 24º is<br />
observed for the change <strong>of</strong> crystal symmetry from<br />
monocl<strong>in</strong>ic symmetry, which is symmetry <strong>of</strong><br />
silicalit-1, becomes orthorombic symmetry which is<br />
symmetry <strong>of</strong> TS-1. This Phenomenon <strong>in</strong>dicates that<br />
titanium atom is <strong>in</strong> the framework structure <strong>of</strong> TS-1<br />
[12].<br />
X-ray diffraktogram pattern <strong>of</strong><br />
Al2O3/TS-1 with various Al2O3 load<strong>in</strong>g variation at<br />
TS-1, showed similar pattern. XRD pattern <strong>of</strong><br />
Al2O3/TS-1 with various <strong>of</strong> Al2O3 load<strong>in</strong>g showed<br />
similar pattern with parent sample TS-1 shown <strong>in</strong><br />
figure 1. Ma<strong>in</strong> top <strong>of</strong> crystal TS-1 emerges at 2θ =<br />
7.88; 8.78; 23.14; 23.9; 24.39; 24.78°. <strong>The</strong> similar<br />
pattern <strong>of</strong> XRD Al2O3/TS-1 <strong>in</strong>dicates that Al2O3<br />
dispersed at surface <strong>of</strong> titanium silikalit-1.<br />
<strong>The</strong>refore, the low content <strong>of</strong> Fe2O3 (up to 4 %wt)<br />
on TS-1 catalyst surface doesn't change the <strong>in</strong>itial<br />
structure framework <strong>of</strong> TS-1.<br />
This f<strong>in</strong>d<strong>in</strong>g <strong>in</strong>dicated that the MFI<br />
structure <strong>of</strong> TS-1 is not collapsed after<br />
impregnation <strong>of</strong> Al2O3.<br />
Catalyst samples <strong>of</strong> TS-1 and Al2O3/TS-<br />
1 showed absorption band at around 1100, 800, and<br />
450 cm -1 , which is vibration mode <strong>of</strong> SiO4 or AlO4<br />
tetrahedral [13]. Absorption band at around 1100<br />
cm-1 is unsimmetrical vibration mode <strong>of</strong> Si-O-Si,<br />
and absorption band at around 800 cm-1 is its<br />
symmetrical vibration mode. Absorption band<br />
appeared at around 1230 and 547 cm -1 . It is<br />
characteristic <strong>of</strong> tetrahedral structure <strong>in</strong> framework<br />
zeolite MFI [14]. Absorption band appeared at<br />
around 970 cm-1 is characteristic <strong>of</strong> TS-1 which is<br />
vibration mode <strong>of</strong> stretch<strong>in</strong>g Si-O from unit [SiO4]<br />
which tied at atom Ti IV with tetrahedral<br />
coord<strong>in</strong>ation <strong>in</strong> TS-1 framework. Absorption band<br />
appear at this wavenumber is evidence that titanium<br />
atom has stayed <strong>in</strong> framework catalyst [15].<br />
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January 24, 2009<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
4 Al2O3/TS-1<br />
2 Al2O3/TS-1<br />
1 Al2O3/TS-1<br />
0,5 Al2O3/TS-<br />
TS-1<br />
Figure 1 X-ray powder patterns <strong>of</strong> samples TS-1 and Al2O3/TS-1 with various load<strong>in</strong>g<br />
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January 24, 2009<br />
1230 cm -1<br />
1100 cm -1<br />
970 cm -1<br />
800 cm -1<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
547 cm -1<br />
4Al2O3/TS-1<br />
2Al2O3/TS-1<br />
1Al2O3/TS-1<br />
450 cm -1<br />
0.5Al2O3/TS-1<br />
TS-1<br />
Figure 2 Framework IR Spectra <strong>of</strong> samples TS-1 and Al2O3/TS-1 with various load<strong>in</strong>g<br />
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January 24, 2009<br />
Hydrophilic<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
Table 1. Hydrophilicity Character Def<strong>in</strong>ition<br />
Sample pass submerged the <strong>in</strong>terfacial phase <strong>in</strong>to water as a whole and<br />
quickly<br />
Hydrophilic Sample pass submerged <strong>in</strong>terfacial phase <strong>in</strong>to water not fairly quickly<br />
but <strong>in</strong> the end all sample is submerged sample<br />
Hydrophilic Initially sample tantalum at <strong>in</strong>terfacial phase and then immerses <strong>in</strong><br />
water slowly and as a whole<br />
Initially sample tantalum at <strong>in</strong>terfacial phase, then some particle will<br />
Partially Hydrophilic submerged <strong>in</strong>to water slowly and some tantalum particles at <strong>in</strong>terfacial<br />
phase, after squealer, all sample is immerses <strong>in</strong> water<br />
Initially sample tantalum at <strong>in</strong>terfacial phase, after squealer, some<br />
Partially Hydrophobic particles there are still tantalum at <strong>in</strong>terfacial phase<br />
Sample will be tantalum permanently at <strong>in</strong>terfacial phase though after<br />
Perfect Hydrophobic squealer is done<br />
Tabel 2. Hydrophilicity Character <strong>of</strong> TS-1 dan Fe2O3/TS-1<br />
Sample Index Character Water sumerged time<br />
(seconds)<br />
TS-1 5 Partially Hydrophobic 1 m<strong>in</strong>utes 10 second<br />
0,5Al2O3/TS-1 5 Partially Hydrophilic 42 second<br />
1Al2O3/TS-1 5 Partially Hydrophilic 38 second<br />
2Al2O3/TS-1 5 Partially Hydrophilic 30 second<br />
4Al2O3/TS-1 5 Partially Hydrophilic 28 second<br />
Hydrophilic test <strong>of</strong> sample was carry<strong>in</strong>g<br />
out us<strong>in</strong>g mixture xylen and water [16]. <strong>The</strong> result<br />
<strong>of</strong> hydrophilic characterization test <strong>of</strong> sample is<br />
given at tables 2.<br />
Table 2 gives an <strong>in</strong>formation about<br />
hydrophilicity properties <strong>of</strong> catalyst samples. Ts-1<br />
sample has hydrophobic character. This result is<br />
similar with the research that had been carried out<br />
by Drago [14]. This phenomena is caused by the<br />
structure <strong>of</strong> TS-1 which active site Ti tetrahedral is<br />
isolated<br />
Presence metal oxide at TS-1, character<br />
<strong>of</strong> hydrophilic <strong>in</strong>creased. This th<strong>in</strong>g proves that<br />
with presence Al2O3 <strong>in</strong>creased hydrophilicity side<br />
<strong>of</strong> TS-1 which is <strong>in</strong>dicated from <strong>in</strong>creases Lewis<br />
side acid.<br />
Conclusion<br />
1. Catalyst TS-1, 0,5% Al2O3/TS-1, 1%<br />
Al2O3/TS-1, 2% Al2O3/TS-1, and 4%<br />
Al2O3/TS-1 has successfully synthesized.<br />
2. <strong>The</strong> addition <strong>of</strong> Al2O3 at TS-1 doesn't change<br />
crystal structure TS-1 with zeolite type MFI.<br />
3. Catalyst sample TS-1 and Al2O3/TS-1 shows<br />
absorption band at around 1100, 800, and 450<br />
cm -1 , which is vibration mode <strong>of</strong> SiO4 or AlO4<br />
tetrahedral. This spectra is characterization <strong>of</strong><br />
MFI.<br />
4. With existence <strong>of</strong> addition <strong>of</strong> Al2O3 at TS-1,<br />
character <strong>of</strong> hydrophilic <strong>in</strong>creased. Al2O3/TS-<br />
1 4% load<strong>in</strong>g gives submerged time at fastest<br />
water compare to other sample.<br />
Acknowledgements<br />
References<br />
[1] Taramasso, M., Perego, G. and Notari, B.<br />
(1983), “Preparation <strong>of</strong> Porous Crystall<strong>in</strong>e<br />
Synthetic Material Comprised <strong>of</strong> Silicon and<br />
Titanium Oxides”. (U. S. Patents No.<br />
4,410,501).<br />
[2] Kurian, M., Sugunan, S. (2006), “Wet Peroxide<br />
Oxidation <strong>of</strong> Phenol Over Mixed Pillared<br />
Montmorillonites”, Chemical Eng<strong>in</strong>eer<strong>in</strong>g<br />
Journal, Vol. 115, pp. 39-146.<br />
[3] Liu, X., Wang, X., Guo, X., Li, G. (2004),<br />
“Effect <strong>of</strong> Solvent on the Propylene<br />
Epoxidation over TS-1 Catalyst”, Catalysis<br />
Today, Vol. 93-95, pp. 505-509.<br />
[4] Choi, J., Yoon, S., Jang, S., Ahn, W. (2006),<br />
“Phenol Hydroxylation Us<strong>in</strong>g Fe-MCM-41<br />
Catalysts”, Catalysis Today, Vol. 111, pp. 280-<br />
287.<br />
[5] Tang, H., Ren, Y., Yue, B., Yan, S., He, H.<br />
(2006), “Cu-<strong>in</strong>corporated Mesoporous<br />
Materials : Synthesis, Characterization and<br />
Catalytic Activity <strong>in</strong> Phenol Hydroxylation”,<br />
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Journal <strong>of</strong> Molecular Catalysis A : Chemical,<br />
Vol. 260, pp. 121-127.<br />
[6] Vayssilov, G. N. dan van Santeny, R. A.<br />
(1998), “Catalytic Activity <strong>of</strong> Titanium<br />
Silicalites—a DFT <strong>Study</strong>”, Journal <strong>of</strong><br />
Catalysis, Vol. 175, pp. 170–174.<br />
[7] Sun, J., Meng, X., Shi, Y., Wang, R., Feng, S.,<br />
Jiang, D., Xu, R., Xiao (2000), “A Novel<br />
Catalyst <strong>of</strong> Cu–Bi–V–O Complex <strong>in</strong> Phenol<br />
Hydroxylation with Hydrogen Peroxide”,<br />
Journal <strong>of</strong> Catalysis, Vol. 193, pp. 199–206.<br />
[8] Wilkenhöner, U., Langhendries, G., van Laar,<br />
F., Baron, G. V., Gammon, D. W., Jacobs, P.<br />
A., dan van Steen, E. (2001), “Influence <strong>of</strong><br />
Pore and Crystall<strong>in</strong>e Titanosilicates on Phenol<br />
Hydroxylation <strong>in</strong> Different Solvents”, Journal<br />
<strong>of</strong> Catalysis, Vol. 203, pp. 201-212.<br />
[9] Bon<strong>in</strong>o, F., Dam<strong>in</strong>, A., Ricchiardi, G., Ricci,<br />
M., Spano`, G., D’Aloisio, R., Zecch<strong>in</strong>a, A.,<br />
Lamberti, C., Prestip<strong>in</strong>o, C., dan Bordiga, S.<br />
(2004), “Ti-Peroxo Species <strong>in</strong> <strong>The</strong> TS-<br />
1/H2O2/H2O System”, Journal <strong>of</strong> Physical<br />
Chemistry B, Vol. 108, pp. 3573-3583.<br />
[10] Liu, H., Lu, G., Yanglong Guo, Yun Guo, dan<br />
Wang, J. (2006), “Chemical K<strong>in</strong>etics <strong>of</strong><br />
Hydroxylation <strong>of</strong> Phenol Catalyzed by TS-<br />
1/Diatomite <strong>in</strong> Fixed-Bed Reactor”, Chemical<br />
Eng<strong>in</strong>eer<strong>in</strong>g Journal, Vol. 116, pp. 179–186.<br />
[11] Armaroli, T., Bevilacqua, M., Trombetta, M.,<br />
Milella, F., Alejandre, A. G., Ramirez, J.,<br />
Notari, B., Willey, R. J., dan Busca, G. (2001),<br />
“A <strong>Study</strong> <strong>of</strong> <strong>The</strong> External and Internal Sites <strong>of</strong><br />
MFI-Type Zeolitic Materials through <strong>The</strong><br />
FTIR Investigation <strong>of</strong> <strong>The</strong> Adsorption <strong>of</strong><br />
Nitriles”, Applied Catalysis A : General, Vol.<br />
216, pp. 59–71.<br />
[12] Li, Y.G., Lee, Y.M., Porter, J.F. (2002), “<strong>The</strong><br />
Synthesis and Caracterization <strong>of</strong> Titanium<br />
Silicalite-1”, Kluwer Academic Publishers, pp.<br />
0022-2461.<br />
[13] Flanigen. E. M. (1976). Structural analysis by<br />
<strong>in</strong>frared spectroscopy. In: Rabo, J. A. ed.<br />
<strong>Zeolite</strong> chemistry and catalysis. ACS<br />
Monograph Vol. 171; pp. 80-117.<br />
[14] Drago, R., Dias, S. C., McGilvray, J. M.,<br />
Mateus, A. L. M. L., 1997, “Acidity and<br />
Hidrophobicity <strong>of</strong> TS-1”, Journal Physic<br />
Chemistry B, vol. 102, pp. 1508-1514.<br />
[15] Li, G., Wang, X., Guo, X.,Liu, S., Zhao, Q.,<br />
Bao, X., L<strong>in</strong>, L. (2001), “Titanium Species <strong>in</strong><br />
Titanium Silicalite TS-1 Prepared By<br />
Hydrothermal Method”, Materials Chemistry<br />
and Physics, Vol. 71, pp. 195-201.<br />
[16] Wang, Z., Wang, T., Wang, Z., J<strong>in</strong>, Y. (2004),<br />
“Organic Modification <strong>of</strong> Ultraf<strong>in</strong>e Particles<br />
us<strong>in</strong>g Carbon-dioxide as the Solvent”, Journal<br />
<strong>of</strong> Powder Technology, Vol. 139, pp. 148-155.<br />
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Synthesis and Characterization <strong>of</strong> Fe2O3/TS-1 Catalyst<br />
Cholifah Endahroyani, Didik Prasetyoko<br />
Laboratorium <strong>of</strong> Inorganic Chemistry, Department <strong>of</strong> Chemistry, Faculty <strong>of</strong> Mathematic and Sciences, Institut<br />
Teknologi Sepuluh Nopember (<strong>ITS</strong>), Surabaya, Indonesia<br />
Correspond<strong>in</strong>g author, Phone: +62-31-5943353<br />
email: didikp@chem.its.ac.id<br />
Introduction<br />
Abstract<br />
Hydroxylation reaction <strong>of</strong> phenol <strong>in</strong>to diphenol, such as hydroqu<strong>in</strong>one and cathecol, has a great role<br />
<strong>in</strong> many <strong>in</strong>dustrial applications. Phenol hydroxylation reaction has been carried out by us<strong>in</strong>g Titanium<br />
Silicalite (TS-1) as catalyst and H2O 2 as an oxidant. TS-1 catalyst has high activity and selectivity for<br />
phenol hydroxylation reaction. However, its hydrophobic sites lead to slow H2O 2 adsorption toward<br />
the active site <strong>of</strong> TS-1. Consequently, the reaction rate <strong>of</strong> phenol hydroxylation reaction is tends to be<br />
low. <strong>Addition</strong> <strong>of</strong> metal oxide can enhanced hydrophilicity character <strong>of</strong> TS-1 catalyst. In this research,<br />
TS-1 catalyst was modified by addition <strong>of</strong> metal oxide Fe 2O 3 by impregnation method. Fe 2O 3/TS-1<br />
catalyst were characterized by X-ray diffraction, FT-IR spectroscopy and hydrophilicity analysis<br />
techniques. <strong>The</strong> new catalyst, Fe2O 3/ TS-1 showed higher hydrophilicity compared to TS-1, and it can<br />
be predicted that the reaction rate <strong>of</strong> phenol hydroxylation will be much faster and will be showed<br />
<strong>in</strong>creas<strong>in</strong>g <strong>of</strong> catalytic activity and selectivity than that <strong>of</strong> parent catalyst, TS-1.<br />
Key words: catalyst, TS-1, Fe2O 3/ TS-1, hydrophilic site, phenol hydroxylation<br />
Hydroxylation reaction <strong>of</strong> phenol to<br />
produce diphenol (catechol and hydroqu<strong>in</strong>one) and its<br />
isomers is one <strong>of</strong> important reaction because phenol<br />
has various important functions such as antioxidant,<br />
polymerization <strong>in</strong>hibitor, photography, rubber<br />
production, antiseptic, reduc<strong>in</strong>g agent, <strong>in</strong>termediate <strong>in</strong><br />
pharmacy, and many others. Hydroxylation reaction<br />
<strong>of</strong> phenol to produce diphenol had draws many<br />
attentions s<strong>in</strong>ce 1970s and some catalysts, both<br />
homogeneous and heterogeneous have been applied<br />
<strong>in</strong> this reaction. Hydroxylation reaction <strong>of</strong> phenol<br />
becomes environmentally friendly reaction when TS-<br />
1 (Titanium Silicalite-1) is applied as catalyst and<br />
aqueous H2O2 as oxidant [1]. TS-1 had draws many<br />
attention s<strong>in</strong>ce last decade because its unique catalytic<br />
characters to selective oxidation reaction <strong>of</strong> organic<br />
compounds like aromatic hydroxylation, epoxidation<br />
alkenes, ammoximation cyclohexanone and oxidation<br />
<strong>of</strong> alkene and alcohol with hydrogen peroxide as<br />
oxidant [2]. TS-1 has been commercialize <strong>in</strong><br />
hydroxylation reaction <strong>of</strong> phenol with high<br />
hydroqu<strong>in</strong>one selectivity (hydroqu<strong>in</strong>one/cathecol<br />
ratio = 1) and high H2O2 efficiency [3].<br />
Hydroxylation reaction <strong>of</strong> phenol with TS-1 catalyst<br />
shows high activity and selectivity, become clean<br />
reaction with low H2O2 non-productive<br />
decomposition, and high catalyst stability [4].<br />
TS-1 can lessens tar product and side<br />
products which have potential as pollutant. Reaction<br />
mechanism <strong>of</strong> phenol hydroxylation is as follows: (1)<br />
TS-1 will decompose H2O2 (oxidation agent) which<br />
has hydrophilic character to form titanium-peroxo<br />
radical (<strong>in</strong>itiation step), then (2) propagation step <strong>in</strong><br />
solution [5]. This mechanism can be expla<strong>in</strong>ed via<br />
titanium-peroxo complex formation mechanism as<br />
<strong>in</strong>termediate from reaction between H2O2 and TS-1<br />
catalyst [2, 6-9]. <strong>The</strong> rate <strong>of</strong> the formation <strong>of</strong><br />
titanium-peroxo depended on the rate <strong>of</strong> H2O2 reach<br />
to active site <strong>in</strong> TS-1. H2O2 is hydrophilic, that is<br />
quite different from hydrophobic character <strong>of</strong> TS-1<br />
[10], consequently the reaction rate <strong>of</strong> phenol<br />
hydroxylation reaction is tends to be low [7]. One <strong>of</strong><br />
the way to <strong>in</strong>crease phenol hydroxylation reaction<br />
rate with TS-1 catalyst is by mak<strong>in</strong>g TS-1 become<br />
more hydrophilic character, and the reaction rate <strong>of</strong><br />
phenol hydroxylation will be much faster and shows<br />
<strong>in</strong>creas<strong>in</strong>g <strong>of</strong> catalytic activity and selectivity higher<br />
than TS-1. Hydrophilic improvement <strong>of</strong> catalyst can<br />
be carried out by addition <strong>of</strong> metal oxide which leads<br />
to <strong>in</strong>creas<strong>in</strong>g <strong>of</strong> acidity properties. <strong>The</strong> existence <strong>of</strong><br />
metal oxide <strong>in</strong> TS-1 catalyst can gives acid site which<br />
capable to <strong>in</strong>crease catalyst hydrophilicity, so that<br />
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reactant adsorption <strong>in</strong> catalyst becomes faster [11,12].<br />
Heterogeneous catalytic process <strong>in</strong> phenol<br />
hydroxylation reaction can be carried out with pure<br />
metals oxide or supported oxide such as MoO3,<br />
CuO/SiO2, Fe2O3, Fe2O3/Al2O3, Co3O4, V2O5 and<br />
colloid particle <strong>of</strong> TiO2. However, this metal oxides<br />
show very low catalytic activity and selectivity [13].<br />
In previous research by Indrayani [14],<br />
synthesis and catalytic activity were carried out with<br />
low-load<strong>in</strong>g <strong>of</strong> MoO3/TS-1 catalyst <strong>in</strong> phenol<br />
hydroxylation reaction. MoO3/TS-1 catalysts have<br />
showed improvement <strong>of</strong> hydrophilicity along with the<br />
<strong>in</strong>creas<strong>in</strong>g <strong>of</strong> MoO3 content <strong>in</strong> MoO3/TS-1 catalyst.<br />
<strong>The</strong> improvement <strong>of</strong> hydrophilic character <strong>of</strong><br />
MoO3/TS-1 catalyst is also accompanied with the<br />
improvement <strong>of</strong> its catalytic activity <strong>in</strong> phenol<br />
hydroxylation reaction. In this research, TS-1 catalyst<br />
was modified by addition <strong>of</strong> metal oxide Fe2O3 on the<br />
surface <strong>of</strong> TS-1. <strong>The</strong> existence <strong>of</strong> Fe2O3 on the TS-1<br />
surface, is expected to br<strong>in</strong>g this new catalyst<br />
(Fe2O3/TS-1) become higher hydrophilic character<br />
compared to TS-1, and the rate <strong>of</strong> phenol<br />
hydroxylation reaction becomes faster than TS-1.<br />
Experimental<br />
Samples TS-1 were prepared accord<strong>in</strong>g to a<br />
procedure described earlier by Taramasso et al.<br />
(1983). Tetraethyl orthosilicates, TEOS (Merck,<br />
98%) conta<strong>in</strong><strong>in</strong>g 0.3145 mol <strong>of</strong> silicon was placed<br />
<strong>in</strong>to a Teflon beaker and vigorously stirred, tetraethyl<br />
orthotitanate, TEOT (Merck, 95%) conta<strong>in</strong><strong>in</strong>g 0.0032<br />
mol <strong>of</strong> titanium <strong>in</strong> isopropyl alcohol was carefully<br />
added dropwise <strong>in</strong>to this TEOS. <strong>The</strong> beaker was<br />
covered with parafilm to avoid hydrolysis. <strong>The</strong><br />
temperature <strong>of</strong> the mixture was raised to 35 o C and the<br />
reactants were mixed homogeneously for half an hour<br />
to obta<strong>in</strong> depolymerisation <strong>of</strong> the titanate oligomers<br />
that may be present <strong>in</strong> TEOT. <strong>The</strong>n the mixture was<br />
cooled to about 0 o C. <strong>The</strong> solution <strong>of</strong><br />
tetrapropylammonium hydroxide, TPAOH (Merck,<br />
20% TPAOH <strong>in</strong> water), which was used as template,<br />
was also cooled to 0 o C. After a few m<strong>in</strong>utes, TPAOH<br />
conta<strong>in</strong><strong>in</strong>g 0.1287 mol <strong>of</strong> TPAOH was added dropwise<br />
slowly <strong>in</strong>to the mixture <strong>of</strong> TEOS and TEOT. At<br />
first, one should wait a few m<strong>in</strong>utes after addition <strong>of</strong> a<br />
few drops <strong>of</strong> TPAOH solution before more TPAOH<br />
solution is added, to avoid precipitation. Stirr<strong>in</strong>g and<br />
cool<strong>in</strong>g were cont<strong>in</strong>ued dur<strong>in</strong>g this process. After the<br />
addition <strong>of</strong> about 10 mL the addition rate <strong>of</strong> TPAOH<br />
solution was <strong>in</strong>creased. When the addition <strong>of</strong> TPAOH<br />
was completed, the mixture was heated <strong>in</strong> the<br />
temperature range <strong>of</strong> 80-90 o C for about 4 h <strong>in</strong> order<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
for the hydrolysis <strong>of</strong> TEOS and TEOT to take place.<br />
Distilled water was added to <strong>in</strong>crease the volume <strong>of</strong><br />
the mixture to about 127 mL, after which a clear gel<br />
was obta<strong>in</strong>ed. <strong>The</strong> gel was transferred <strong>in</strong>to a 150 mL<br />
autoclave and heated at 175 o C under static condition.<br />
<strong>The</strong> material was recovered after 4 days <strong>of</strong><br />
hydrothermal crystallization by centrifugation and<br />
wash<strong>in</strong>g with excess distilled water. A white powder<br />
was obta<strong>in</strong>ed after dry<strong>in</strong>g <strong>in</strong> air at 100 o C overnight.<br />
Silicalite was synthesized by us<strong>in</strong>g the same<br />
procedure without the addition <strong>of</strong> TEOT. <strong>The</strong><br />
calc<strong>in</strong>ation <strong>of</strong> the sample to remove the template was<br />
carried out under static air at 550 o C for 5 h with<br />
temperature rate at 1 o /m<strong>in</strong> [15].<br />
Catalyst TS-1 and Fe2O3/TS-1 is<br />
characterized with X-ray diffraction (XRD)<br />
technique, X-ray powder diffraction (XRD) patterns<br />
were collected us<strong>in</strong>g the Ni-filtered Cu-Kα radiation<br />
(λ = 1.5406 Å), the <strong>in</strong>frared spectrum is used for IR<br />
absorption spectra analysis with KBr palette method.<br />
<strong>The</strong> <strong>in</strong>frared spectrum is recorded from wavenumber<br />
1400–400 cm −1 . Catalysts hydrophilicity is analyzed<br />
by catalyst sample powder dispersion method at water<br />
phase and organic phase mixture (water and xylene).<br />
A mixture <strong>of</strong> xylene and water, which do not mix<br />
with each other, is employed to test the hydrophobic<br />
characteristics <strong>of</strong> the samples. Xylene and water <strong>of</strong><br />
the same volume are added <strong>in</strong>to a test tube to form a<br />
stable phase <strong>in</strong>terface Unmodified and modified<br />
particles are, respectively, dispersed <strong>in</strong> the xylene–<br />
water system and stirred. After the mixture has<br />
stabilized, the hydrophobic characteristics can be<br />
qualitatively evaluated by <strong>in</strong>spect<strong>in</strong>g the state <strong>of</strong> the<br />
float<strong>in</strong>g/s<strong>in</strong>k<strong>in</strong>g <strong>of</strong> samples at the <strong>in</strong>terface. <strong>The</strong><br />
criterion <strong>of</strong> hydrophobic <strong>in</strong>dex is shown <strong>in</strong> table 2.<br />
Results and Discussion<br />
Fe2O3/TS-1 catalysts were characterized by<br />
X-ray diffraction technique. <strong>The</strong> XRD patterns were<br />
showed <strong>in</strong> Figure 1. Characteristic diffraction l<strong>in</strong>es <strong>of</strong><br />
TS-1 is observed at 2θ = 7,94; 8; 23.08; 23.62; 23.88;<br />
23.92°. <strong>The</strong> peak at 2θ around 24º is observed for the<br />
change <strong>of</strong> crystal symmetry from monocl<strong>in</strong>ic<br />
symmetry, which is symmetry <strong>of</strong> silicalite-1, becomes<br />
orthorombic symmetry which is symmetry <strong>of</strong> TS-1.<br />
This Phenomenon <strong>in</strong>dicates that titanium atom is<br />
already <strong>in</strong> the framework structure <strong>of</strong> TS-1 [18]. Xray<br />
diffraction pattern <strong>of</strong> Fe2O3/TS-1 with various <strong>of</strong><br />
Fe2O3 load<strong>in</strong>g showed similar pattern with parent TS-<br />
1 sample. This f<strong>in</strong>d<strong>in</strong>g <strong>in</strong>dicated that the MFI<br />
structure <strong>of</strong> TS-1 is not collapsed after impregnation<br />
<strong>of</strong> Fe2O3. <strong>The</strong>refore, the low content <strong>of</strong> Fe2O3 (up to<br />
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4% wt) on TS-1 catalyst surface doesn't change the <strong>in</strong>itial structure framework <strong>of</strong> TS-1.<br />
Figure 1. X-ray Diffractogram Pattern <strong>of</strong> TS-1 dan Fe2O3/TS-1<br />
<strong>The</strong> XRD peak <strong>in</strong>tensity <strong>of</strong> the samples at 2θ around<br />
23.00 o is decrease along with the <strong>in</strong>creas<strong>in</strong>g <strong>of</strong> Fe2O3<br />
load<strong>in</strong>g <strong>in</strong> TS-1 (table 1). This result <strong>in</strong>dicates that<br />
Fe2O3 were already located on the TS-1 surface.<br />
Table 1. Crystall<strong>in</strong>ity <strong>of</strong> Fe2O3/TS-1 and TS-1<br />
Intensity at<br />
Samples Code<br />
2θ = 23.00 o ,<br />
Cps<br />
TS-1 (2θ = 23.060 o )<br />
0,5Fe2O3/TS-1 (2θ = 23.167 o )<br />
1Fe2O3/TS-1 (2θ = 23.183 o )<br />
2Fe2O3/TS-1 (2θ = 23.138 o )<br />
4Fe2O3/TS-1 (2θ = 23.302 o 3288<br />
3030<br />
2964<br />
2349<br />
) 2332<br />
Infrared spectra <strong>of</strong> the samples are shown <strong>in</strong><br />
fig 2. Catalyst samples <strong>of</strong> TS-1 and Fe2O3/TS-1<br />
shows absorption band at wavenumber around 1100,<br />
800, and 450 cm -1 , which is vibration mode <strong>of</strong> SiO4 or<br />
AlO4 tetrahedral. Absorption band at wavenumber<br />
around 1100 cm -1 is unsymmetrical vibration mode <strong>of</strong><br />
Si-O-Si, and absorption band at wavenumber around<br />
800 cm -1 is its symmetrical vibration mode.<br />
Absorption band at wavenumber around 1230 and<br />
547 cm -1 is characteristic for tetrahedral structure <strong>in</strong><br />
framework zeolite MFI [19]. Absorption band at<br />
wavenumber around 970 cm -1 is characteristic <strong>of</strong> TS-<br />
1 which is vibration mode <strong>of</strong> stretch<strong>in</strong>g Si-O from<br />
unit [SiO4] which tied at atom Ti 4+ with tetrahedral<br />
coord<strong>in</strong>ation <strong>in</strong> TS-1 framework. Absorption band at<br />
this wavenumber is evidence that titanium atom has<br />
already stayed <strong>in</strong>side the structure <strong>of</strong> catalyst<br />
framework [20].<br />
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%T<br />
1230 cm -1<br />
1100 cm -1<br />
970 cm -1<br />
800 cm -1<br />
547 cm -1<br />
Figure 2. IR Spectra <strong>of</strong> TS-1 and Fe2O3/TS-1 samples with various load<strong>in</strong>g<br />
wavenumber, cm -1<br />
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450 cm -1<br />
1400 1300 1200 1100 1000 900 800 700 600 500 400<br />
4 Fe 2O3/TS-1<br />
2 Fe2O3/TS-1<br />
1 Fe 2O3/TS-1<br />
0.5 Fe2O3/TS-1<br />
TS1<br />
silicalite<br />
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Hydrophilic<br />
Table 2. Hydrophilicity Character Def<strong>in</strong>ition [21]<br />
Samples s<strong>in</strong>k <strong>in</strong>to water quickly and completely<br />
Hydrophilic Samples s<strong>in</strong>k <strong>in</strong>to water not so quickly, but completely<br />
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Hydrophilic Samples float at first and then s<strong>in</strong>k <strong>in</strong>to water slowly and completely<br />
Partially Hydrophilic Samples float at first and then s<strong>in</strong>k <strong>in</strong>to water slowly. Part <strong>of</strong> the powder<br />
floats on surface <strong>of</strong> water and, after agitation, s<strong>in</strong>ks <strong>in</strong>to water<br />
completely<br />
Partially Hydrophobic Samples float on the surface <strong>of</strong> water. After a long time agitation, part <strong>of</strong><br />
the powder still floats on the surface <strong>of</strong> water<br />
Completely Hydrophobic Samples float on the surface <strong>of</strong> water even with strong agitation for a<br />
long time<br />
Table 3. Hydrophobicity Character <strong>of</strong> TS-1 and Fe2O3/TS-1 Samples<br />
Sample Index Character Water s<strong>in</strong>ks time<br />
(seconds)<br />
TS-1 5 Partially Hydrophobic<br />
1 : 08.4<br />
0,5Fe2O3/TS-1<br />
1Fe2O3/TS-1<br />
2Fe2O3/TS-1<br />
4Fe2O3/TS-1<br />
Catalyst hydrophilicity character analysis is<br />
carried out by catalyst samples dispersion method <strong>in</strong><br />
the mixture <strong>of</strong> water and organic phase (xylene).<br />
<strong>The</strong> results <strong>of</strong> hydrophobic tests are shown<br />
<strong>in</strong> Table 3. All samples seem to show similar<br />
behavior dur<strong>in</strong>g the hydrophilicity test, this <strong>in</strong>dicates<br />
that the addition <strong>of</strong> metal oxide on TS-1 surface<br />
didn’t give too much effect <strong>in</strong> TS-1 catalyst<br />
properties, which is partially hydrophobic.<br />
Nevertheless, the addition <strong>of</strong> metal oxide on TS-1<br />
surface makes Fe2O3/TS-1 catalyst become much<br />
more hydrophilic than TS-1 catalyst. It can be seen <strong>in</strong><br />
table 3 that the higher Fe2O3 load<strong>in</strong>g <strong>in</strong> TS-1 catalyst<br />
resulted <strong>in</strong> the faster s<strong>in</strong>ks <strong>in</strong>to water. From Table 3,<br />
it can be concluded that there is the <strong>in</strong>creas<strong>in</strong>g <strong>of</strong> the<br />
catalyst hydrophilicity character along with the<br />
<strong>in</strong>creas<strong>in</strong>g <strong>of</strong> metal oxide Fe2O3 content at TS-1<br />
catalyst surface.<br />
5 Partially Hydrophobic<br />
5 Partially Hydrophobic<br />
1 : 02.4<br />
0 : 47.2<br />
5 Partially Hydrophobic 0 : 36.9<br />
5 Partially Hydrophobic 0 : 34.1<br />
Conclusion<br />
1. Catalyst TS-1, 0,5Fe2O3/TS-1, 1Fe2O3/TS-<br />
1, 2Fe2O3/TS-1, and 4Fe2O3/TS-1 has been<br />
successfully synthesized<br />
2. Catalyst 0,5Fe2O3/TS-1, 1Fe2O3/TS-1,<br />
2Fe2O3/TS-1, and 4Fe2O3/TS-1 still have<br />
orthorombic structure MFI type which is<br />
characteristic <strong>of</strong> TS-1 catalyst.<br />
3. Catalyst hydrophilicity character <strong>in</strong>creases<br />
successively from TS-1, 0.5Fe2O3/TS-1,<br />
1%Fe2O3/TS-1, 2Fe2O3/TS-1, and<br />
4Fe2O3/TS-1.<br />
Acknowledgement<br />
We gratefully acknowledge fund<strong>in</strong>g from the<br />
Directorate General <strong>of</strong> Higher Education, Indonesia,<br />
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References<br />
[1] Tang, H., Ren, Y., Yue, B., Yan, S., He, H.<br />
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[2] Liu, H., Lu, G., Yanglong Guo, Yun Guo, dan<br />
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[3] Choi, J., Yoon, S., Jang, S., Ahn, W. (2006),<br />
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280-287.<br />
[4] Liu, X., Wang, X., Guo, X., Li, G. (2004), “Effect<br />
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[5] Kurian, M., Sugunan, S. (2006), “Wet Peroxide<br />
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Journal, Vol. 115, hal. 39-146.<br />
[6] Vayssilov, G. N. dan van Santeny, R. A. (1998),<br />
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[7] Sun, J., Meng, X., Shi, Y., Wang, R., Feng, S.,<br />
Jiang, D., Xu, R., Xiao (2000), “A Novel<br />
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[9] Bon<strong>in</strong>o, F., Dam<strong>in</strong>, A., Ricchiardi, G., Ricci, M.,<br />
Spano`, G., D’Aloisio, R., Zecch<strong>in</strong>a, A.,<br />
Lamberti, C., Prestip<strong>in</strong>o, C., dan Bordiga, S.<br />
(2004), “Ti-Peroxo Species <strong>in</strong> <strong>The</strong> TS-<br />
1/H2O2/H2O System”, Journal <strong>of</strong> Physical<br />
Chemistry B, Vol. 108, hal. 3573-3583.<br />
[10] Armaroli, T., Bevilacqua, M., Trombetta, M.,<br />
Milella, F., Alejandre, A. G., Ramirez, J.,<br />
Notari, B., Willey, R. J., dan Busca, G.<br />
(2001), “A <strong>Study</strong> <strong>of</strong> <strong>The</strong> External and<br />
Internal Sites <strong>of</strong> MFI-Type Zeolitic<br />
Materials through <strong>The</strong> FTIR Investigation <strong>of</strong><br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
<strong>The</strong> Adsorption <strong>of</strong> Nitriles”, Applied<br />
Catalysis A : General, Vol. 216, hal. 59–71.<br />
[11] Nur, H., Prasetyoko, D., Ramli, Z., Endud, S.<br />
(2004), “Sulfation: A simple Method to<br />
enhance the Catalytic Activity <strong>of</strong> TS-1 <strong>in</strong><br />
Epoxidation <strong>of</strong> 1-octene with Aqueous<br />
Hydrogen Peroxide”, Catalysis<br />
Communications . Vol.5, hal. 725–728.<br />
[12] Prasetyoko, D., Ramli, Z., Endud, S., Nur, H.<br />
(2005), “Enhancement <strong>of</strong> Catalytic Activity<br />
<strong>of</strong> Titanosilicalite-1–Sulfated Zirconia<br />
Comb<strong>in</strong>ation Towards Epoxidation <strong>of</strong> 1-<br />
Octene With Aqueous Hydrogen Peroxide”,<br />
Reaction K<strong>in</strong>etics Catalysis Letter, Vol. 86,<br />
hal. 83-89.<br />
[13] Ray, S., Mapolie, S. F., Darkwa, J. (2007),<br />
“Catalytic Hydroxylation <strong>of</strong> Phenol us<strong>in</strong>g<br />
Immobilized Late Transition Metal<br />
Salicylaldim<strong>in</strong>e Complexes”, Journal <strong>of</strong><br />
Molecular Catalysis A : Chemical, Vol. 267,<br />
hal. 143-148.<br />
[14] Indrayani Suci, (2008), Aktivitas Katalitik<br />
MoO3/TS-1 pada Reaksi Hidroksilasi Fenol<br />
menggunakan H2O2, Tesis M.Si, Jurusan<br />
Kimia FMIPA Institut Teknologi Sepuluh<br />
Nopember, Surabaya.<br />
[15] Taramasso, M., Perego, G. and Notari, B.<br />
(1983), “Preparation <strong>of</strong> Porous Crystall<strong>in</strong>e<br />
Synthetic Material Comprised <strong>of</strong> Silicon and<br />
Titanium Oxides”. (U. S. Patents No.<br />
4,410,501).<br />
[16] Choudhary, V. R., Jana, S. K., Mamman, A. S.<br />
(2002), “Benzylation <strong>of</strong> Benzene by Benzyl<br />
Chloride over Fe-modified ZSM-5 and H-β<br />
<strong>Zeolite</strong>s and Fe2O3 or FeCl3 deposited on<br />
Micro-, Meso-, and Macro-porous<br />
Supports”, Microporous and Mesoporous<br />
Materials, Vol. 56, hal. 65-71.<br />
[17] Hattori, H., Ogawa, T., Jones, F., Knudson, C.,<br />
Willson, W., R<strong>in</strong>dt, J., Mitchell, M.,<br />
Stenberg, V., Radonovich, L., Janikowski, S.<br />
(1985), “Reduction Activities <strong>of</strong> Fe2O3/SiO2<br />
Catalysts with Hydrogen Sulphide and<br />
Hydrogen”, Fuel, Vol. 65, hal. 780-785.<br />
[18] Li, Y.G., Lee, Y.M., Porter, J.F. (2002), “<strong>The</strong><br />
Synthesis and Caracterization <strong>of</strong> Titanium<br />
Silicalite-1”, Kluwer Academic Publishers,<br />
hal. 0022-2461.<br />
[19] Drago, R. S., Dias, S. C., McGilvray, J. M.,<br />
Mateus, A. L. M. L. (1998), “Acidity and<br />
Hydrophobicity <strong>of</strong> TS-1”, Journal <strong>of</strong><br />
Physical Chemistry, Vol. 102, hal. 1508-<br />
1514.<br />
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[20] Li, G., Wang, X., Guo, X.,Liu, S., Zhao, Q., Bao,<br />
X., L<strong>in</strong>, L. (2001), “Titanium Species <strong>in</strong><br />
Titanium Silicalite TS-1 Prepared By<br />
Hydrothermal Method”, Materials<br />
Chemistry and Physics, Vol. 71, hal. 195-<br />
201.<br />
[21] Wang, Z., Wang, T., Wang, Z., J<strong>in</strong>, Y. (2004),<br />
“Organic Modification <strong>of</strong> Ultraf<strong>in</strong>e Particles<br />
us<strong>in</strong>g Carbon-dioxide as the Solvent”,<br />
Journal <strong>of</strong> Powder Technology, Vol. 139,<br />
hal. 148-155.<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
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January 24, 2009<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
New Mixed Ligands Complexes <strong>of</strong> Z<strong>in</strong>c(II), Cadmium(II) and Bismuth(III)<br />
With Dithiocarbamates and 2,2’-Bipyridyl<br />
Normah Awang 1 , Ibrahim Baba 2 and Bohari Mohd Yam<strong>in</strong> 2<br />
1 Environmental Health Programme, Faculty <strong>of</strong> Allied Health Sciences, Universiti Kebangsaan Malaysia, Jalan Raja<br />
Muda Abdul Aziz, 50300 Kuala Lumpur<br />
normahawang1969@yahoo.com<br />
+60326878034<br />
2 School <strong>of</strong> Chemical Sciences and Food Technology, Faculty Science and Technology, Universiti Kebangsaan<br />
Malaysia, 43600 Bangi, Selangor<br />
Abstract<br />
A new series <strong>of</strong> z<strong>in</strong>c(II), cadmium(II) and bismuth(III) complexes with mixed ligands, dithiocarbamate and 2,2’bipyridyl<br />
were successfully synthesized us<strong>in</strong>g “<strong>in</strong> situ” method. Microelemental analysis data <strong>of</strong> the complexes are<br />
<strong>in</strong> agreement with the general formula, M[S CNR’R”] 2 nbipy (M = Zn, Cd & Bi; R = s-butyl, R’ = propyl; R =<br />
benzyl, i-propyl; bipy = 2,2’-bipyridyl). Infrared spectra <strong>of</strong> the complexes showed that the thioureide ν(C N)<br />
band is <strong>in</strong> the regions 1438 – 1453 cm -1<br />
-1<br />
bidentate nature <strong>of</strong> the chelated dithiocarbamate ligands. <strong>The</strong><br />
. <strong>The</strong> unsplitt<strong>in</strong>g band <strong>of</strong> ν(C-S) <strong>in</strong> the region 930 – 1000 cm<br />
<strong>in</strong>dicates the<br />
13<br />
C NMR chemical shift <strong>of</strong> the carbon atom <strong>of</strong> the N-<br />
CS 2 group appeared <strong>in</strong> the range <strong>of</strong> 201.67 – 208.27 ppm. <strong>The</strong> crystal structure <strong>of</strong> z<strong>in</strong>c(II)<br />
benzylisopropyldithiocarbamate(2,2’-bipyridyl) supports the elemental and spectroscopic data <strong>in</strong> which two<br />
dithiocarbamates and one bipy ligands chelated to the central Zn atom <strong>in</strong> bidentate manner <strong>in</strong> a distorted<br />
octahedron environment.<br />
Keywords: dithiocarbamate; chlor<strong>of</strong>orm; IR spectra; biological activity<br />
Introduction<br />
For several years considerable attention has been paid<br />
to dithiocarbamate compounds. Firstly, their<br />
biological effects have been researched, <strong>in</strong>clud<strong>in</strong>g<br />
antialkylation, anti-HIV properties [1] and antitumor<br />
activity aga<strong>in</strong>st leucemic cells [2]. Some<br />
dithiocarbamate complexes also have some practical<br />
applications. For example, they are used <strong>in</strong><br />
agriculture as fungiside and pesticide [3].<br />
<strong>The</strong> 1:1 adducts <strong>of</strong> z<strong>in</strong>c and cadmium<br />
dialkyldithiocarbamates with 2,2’-bipyridyl have<br />
been reported and some <strong>of</strong> these complexes are very<br />
active accelerators for the vulcanization <strong>of</strong> rubber and<br />
low temperature vulcanization <strong>of</strong> latex [4]. <strong>The</strong><br />
crystal structure <strong>of</strong> Zn[S2CN(C2H5)2]2(2,2’-bipy) has<br />
been reported [5].<br />
In spite <strong>of</strong> the fact that many<br />
dithiocarbamate compounds with different transition<br />
metals are described <strong>in</strong> the chemical literature, we<br />
have only considered Zn(II), Cd(II) and Bi(III)<br />
coord<strong>in</strong>ation compounds with non-symmetrical<br />
dithiocarbamates with the general formula<br />
M[S 2 CNR’R”] nbipy. (M = Zn, Cd & Bi; R = s-butyl,<br />
R’ = propyl; R’ = benzyl, R”i-propyl; bipy = 2,2’bipyridyl).<br />
So far, no <strong>in</strong>formation on complexes <strong>of</strong><br />
this type with the sec-butylpropyl and<br />
benzylisopropyldithiocarbamate ligands were found<br />
<strong>in</strong> the literature.<br />
Materials and Methods<br />
Reagents<br />
All the reagents and solvents employed were<br />
commercially available analytical grade materials and<br />
were used as supplied, without further purification. Nbenzylisopropylam<strong>in</strong>e,<br />
2,2’-bipyridyl and ethanol<br />
(95%) were obta<strong>in</strong>ed from Fluka Chemicals. Carbon<br />
disulphide and methanol (99.5%) from Ajax<br />
Chemical Ltd. Bismuth(III) chloride was obta<strong>in</strong>ed<br />
from Hayashi Pure Chemical Indsutries Ltd.<br />
Cadmium(II) dichloride monohydrate, chlor<strong>of</strong>orm<br />
and z<strong>in</strong>c(II) chloride were purchased from Merck.<br />
Physical and spectroscopic measurement<br />
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Elemental analyses were performed on a Fision EA<br />
1108 CHN Elemental Analyser. Melt<strong>in</strong>g po<strong>in</strong>ts were<br />
determ<strong>in</strong>d on a Electrothermal IA 9100 apparatus. 1<br />
H<br />
and 13<br />
C NMR spectra were recorded <strong>in</strong> CDCl3<br />
solution on a Joel JNM – LA400 spectrometer with<br />
chemical shifts relative to tetrametylsilane. IR spectra<br />
were obta<strong>in</strong>ed as KBr pellets on a Perk<strong>in</strong> Elmer<br />
FTIR Model GX spectrophotometer <strong>in</strong> the frequency<br />
range 4000 – 500 cm -1<br />
and 500 cm -1<br />
- 200 cm -1 .<br />
Synthesis <strong>of</strong> dithiocarbamate complexes<br />
<strong>The</strong> mixed-ligand complexes were prepared by<br />
add<strong>in</strong>g equimolar <strong>of</strong> metal dithiocarbamate<br />
compound (z<strong>in</strong>c(II), cadmium(II) and bismuth(III))<br />
and 2,2’-bipyridyl <strong>in</strong> the mixture <strong>of</strong> ethanol and<br />
chlor<strong>of</strong>orm solutions. <strong>The</strong> method used to prepare the<br />
metal dithiocarbamate compounds were synthesized<br />
by a method reported earlier [6]. <strong>The</strong> result<strong>in</strong>g<br />
mixture was stirred for one hour and the solvent was<br />
allowed to evaporate at room temperature. After two<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
days, the crystals separated out and washed with cold<br />
ethanol.<br />
Results And Discussion<br />
<strong>The</strong> M n+ [S2CNR’R”]m(bipy) complexes (n = 2, m = 2;<br />
n = 3, m = 3; R’ = s-C4H9, R” = CH3; R’ = C7H7, i-<br />
C3H7; bipy = 2,2’-bipyridyl) were prepared via a<br />
straightforward process <strong>in</strong>volv<strong>in</strong>g only two steps. All<br />
the compounds were non-hgroscopic and stable <strong>in</strong> air.<br />
<strong>The</strong>y were <strong>in</strong>soluble or spar<strong>in</strong>gly soluble <strong>in</strong> most<br />
common organic solvents and very soluble <strong>in</strong><br />
chlor<strong>of</strong>orm. <strong>The</strong> results <strong>of</strong> elemental analyses (Table<br />
1) are <strong>in</strong> good agreement with those required by the<br />
proposed formulae. <strong>The</strong> formation <strong>of</strong> these complexes<br />
may proceed accord<strong>in</strong>g to the follow<strong>in</strong>g equation<br />
given below.<br />
M[S2CNR’R”]n + C10H8N2 →<br />
M[S2CNR’R”]n(C10H8N2)<br />
M = Bi(III), Cd(II), Zn(II); n = 2 or 3; R’ = C7H7, R”<br />
= i-C3H7; R’ = s-C4H9, R” = C3H7<br />
Table 1. Physical and elemental analysis data <strong>of</strong> mixed-ligand complexes<br />
Compound Colour Melt<strong>in</strong>g<br />
po<strong>in</strong>t<br />
(°C)<br />
Zn[S2CN(C7H7)(iC3H7)]2bipy Yellow 165.9-<br />
(compound 1)<br />
166.5<br />
Cd[S2CN(C7H7)(iC3H7)]2bipy Yellow 223.2-<br />
(compound 2)<br />
224.4<br />
Zn[S2CN(sC4H9)(C3H7)]2bipy Yellow 133.8-<br />
(compound 3)<br />
134.3<br />
Cd[S2CN(sC4H9)(C3H7)]2bipy Yellow 194.8-<br />
(compound 4)<br />
Bi[S2CN(sC4H9)(C3H7)]3bipy<br />
(compound 5)<br />
195.3<br />
Orange 115.8-<br />
116.5<br />
<strong>The</strong> <strong>in</strong>frared spectra <strong>of</strong> the title compounds<br />
and important characteristic absorption bands, along<br />
with their proposed assignments are summarized <strong>in</strong><br />
Table 2. <strong>The</strong> IR spectra <strong>of</strong> the compounds are very<br />
similat to each other, except some slight shifts and<br />
<strong>in</strong>tensity change <strong>of</strong> a few vibration bands caused by<br />
different metal ions, which <strong>in</strong>dicate that the<br />
compounds have similar structures. Coord<strong>in</strong>ation <strong>in</strong><br />
the mixed-ligand ma<strong>in</strong>ly affected the C-N and C-S<br />
stretch<strong>in</strong>g bands [7].<br />
% Found (calcd)<br />
C H N S M<br />
55.80<br />
(57.37)<br />
52.30<br />
(53.60)<br />
52.83<br />
(51.88)<br />
47.68<br />
(48.12)<br />
43.84<br />
(43.64)<br />
5.03<br />
(5.38)<br />
4.65<br />
(5.02)<br />
7.27<br />
(6.65)<br />
6.65<br />
(6.17)<br />
6.76<br />
(5.99)<br />
8.36<br />
(8.37)<br />
7.51<br />
(7.82)<br />
9.55<br />
(9.31)<br />
9.71<br />
(8.64)<br />
8.57<br />
(7.49)<br />
20.23<br />
(19.12)<br />
17.34<br />
(17.87)<br />
22.18<br />
(21.28)<br />
19.09<br />
(19.74)<br />
21.80<br />
(20.54)<br />
11.32<br />
(9.77)<br />
14.07<br />
(15.69)<br />
8.73<br />
(10.87)<br />
16.00<br />
(17.33)<br />
20.87<br />
(22.35)<br />
Table 2. <strong>The</strong> important <strong>in</strong>frared absorption bands <strong>of</strong><br />
compound 1-5 (cm -1 )<br />
Compound ν(C N) ν(N- ν(C S) ν(M-<br />
1 1440 1174 967 386<br />
2 1438 1171 970 387<br />
3 1441 1196 967 376<br />
4 1439 1194 957 386<br />
5 1453 1189 951 358<br />
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<strong>The</strong> selected 1 H NMR peaks for compounds<br />
1-5 are showned <strong>in</strong> Table 3. <strong>The</strong> aromatic proton<br />
signals for 2,2’-bipyridyl <strong>in</strong> compounds 1-5 were<br />
observed <strong>in</strong> the range 7.33 – 9.01 ppm. This signal<br />
was not observed <strong>in</strong> the 1 H NMR spectra for metal<br />
dithiocarbamate compounds. Two proton signals<br />
from 2,2’-bipyridyl <strong>in</strong> compounds 1-4 have shifted<br />
Table 3. <strong>The</strong> selected 1 H and 13 C NMR data (δ, ppm) for compounds 1-5<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
which one signal to downfield and the other one<br />
signal to upfield. <strong>The</strong>se shifts <strong>in</strong>dicate that 2,2’bipyridyl<br />
has been coord<strong>in</strong>ated to the metal atom. <strong>The</strong><br />
IR spectra data comb<strong>in</strong>ed with these data showed that<br />
the 2,2’-bipyridyl has coord<strong>in</strong>ated to the metal atom<br />
<strong>in</strong> all <strong>of</strong> these compounds.<br />
Compound Formula<br />
1<br />
H NMR<br />
(bipy)<br />
2,2’-bipyridyl (C10H8N2) 8.70 (d), 8.41 (d), 7.83 (t),<br />
7.33 (t)<br />
1 Zn[S2CN(C7H7)(iC3H7)]2bipy<br />
8.95 (d), 8.26 (d), 7.86 (t),<br />
7.33 (t)<br />
2 Cd[S2CN(C7H7)(iC3H7)]2bipy<br />
9.01 (d), 8.19 (d), 7.95 (t),<br />
7.48(t)<br />
3 Zn[S2CN(sC4H9)(C3H7)]2bipy<br />
8.82 (d), 8.35 (d), 7.85 (t),<br />
7.35 (t)<br />
4 Cd[S2CN(sC4H9)(C3H7)]2bipy<br />
8.95 (d), 8.26 (d), 7.86 (t),<br />
7.33 (t)<br />
5 Bi[S2CN(sC4H9)(C3H7)]3bipy<br />
8.70 (d), 8.40 (d), 7.84 (t),<br />
7.33 (t)<br />
<strong>The</strong> most important signal <strong>in</strong> the 13 C NMR<br />
spectra was the chemical shift for N 13 CS2 carbon. <strong>The</strong><br />
N 13 CS2 chemical shifts for compounds 1-5 were<br />
observed <strong>in</strong> the range 201.67-208.27 ppm which not<br />
observed <strong>in</strong> the 13 C NMR spectra for 2,2’-bipyridyl<br />
compund. <strong>The</strong> N 13 CS2 chemical shift for compounds<br />
1 and 2 dropped slightly to downfield compared to<br />
the parent compounds (205.08 and 205.77 ppm<br />
respectively). <strong>The</strong> high values <strong>of</strong> N 13 CS2 chemical<br />
shifts could be expla<strong>in</strong>ded by an <strong>in</strong>crease <strong>of</strong> π bond<br />
order <strong>in</strong> the whole NCS2 moiety [8] which means that<br />
the chelation <strong>of</strong> 2,2’-bipyridyl to the metal atoms has<br />
promoted the delocalization <strong>of</strong> the unshared electron<br />
pair <strong>in</strong> the nitrogen atoms <strong>in</strong> the dithiocarbamate<br />
groups.<br />
Suitable crystal for X-ray crystallographic<br />
studies <strong>of</strong> compound 2 were obta<strong>in</strong>ed by slow<br />
evaporation <strong>of</strong> a chlor<strong>of</strong>orm:ethanol mixture at room<br />
temperature. <strong>The</strong> dithiocarbamate ligands and 2,2’bipyridyl<br />
are bidentically chelated to the z<strong>in</strong>c atom<br />
and the coord<strong>in</strong>ation geometry around z<strong>in</strong>c was<br />
distorted octahedral.<br />
Conclusion<br />
<strong>The</strong> elemental, spectroscopic and crystallographic<br />
data showed that the new mixed-ligand complexes<br />
have been successfully synthesized. <strong>The</strong><br />
13<br />
C NMR<br />
(N 13 CS2)<br />
-<br />
206.62<br />
208.27<br />
203.88<br />
205.93<br />
201.67<br />
dithiocarbamate ligands and 2,2’-bipyridyl were<br />
chelated to the metal atom to form the<br />
hexacoord<strong>in</strong>ated mixed-ligand complexes. <strong>The</strong><br />
crystallographic study <strong>of</strong> compound 2 showed that<br />
both <strong>of</strong> the dithocarbamate ligands and 2,2’-bipyridyl<br />
were bidentically chelated to the z<strong>in</strong>c atom.<br />
Acknowledgement<br />
<strong>The</strong> authors gratefully acknowledge the research<br />
grant provided by <strong>The</strong> Malaysian Government (IRPA<br />
09-02-02-0048-EA144) and Universiti Kebangsaan<br />
Malaysia for f<strong>in</strong>ancial support. Technical support<br />
from laboratory assistants <strong>of</strong> Faculty Science and<br />
Technology, Universiti Kebangsaan Malaysia is<br />
gratefully acknowledged.<br />
References<br />
[1] Hersh, E.M., Brewton,G., Abrams,D., Bartlett,J.,<br />
Galp<strong>in</strong>,J., Gill,P., Gorter,R., Gottlieb,M.,<br />
Jonikas,J.J., Landesman,S., Lev<strong>in</strong>e,A.,<br />
Marcel,A., Petersen,E.A., Whiteside,M.,<br />
Zahradnik,J., Negron,C., Boutitie,F., Caraux,J.,<br />
Dupuy,J. & Salmi,R. 1991. Ditiocarb sodium<br />
(diethyldithiocarbamate) therapy <strong>in</strong> patients with<br />
symptomatic HIV <strong>in</strong>fection and AIDS: A<br />
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randomized, double-bl<strong>in</strong>d, placebo-controled,<br />
multicenter study. J. Am. Med. Assoc.,<br />
265:1538–1544.<br />
[2] Mital, R., Ja<strong>in</strong>, N. & Srivastava, T.S. 1989.<br />
Synthesis, characterization and cytotoxic studies<br />
<strong>of</strong> diam<strong>in</strong>e and diim<strong>in</strong>e palladium(II) complexes<br />
<strong>of</strong> diethyldithiocarbamate and b<strong>in</strong>d<strong>in</strong>g <strong>of</strong> these<br />
and analogous plat<strong>in</strong>um(II) complexes with<br />
DNA. Inorganica Chimica Acta, 166(1):135-140.<br />
[3] Montgomery, J.H. 1993. Agrochemical Desk<br />
Reference Environmental Data, Lewis Publisher,<br />
Michigan.<br />
[4] Bateman, L. 1963. <strong>The</strong> chemistry and physics <strong>of</strong><br />
rubber like substance, Maclaren, London.<br />
[5] Zemskova, S. M., Gl<strong>in</strong>skaya, L. A., Durasov, V.<br />
B., Klevtsova, R. F. & Larionov, S. V. 1994.<br />
Mixed-ligand complexes <strong>of</strong> z<strong>in</strong>c(II) and<br />
cadmium(II) diethyldithiocarbamates with 2, 2’-<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
bipyridyl and 4, 4’-bipyridyl: synthesis, structure<br />
and thermal properties. J. Struct. Chem. 34: 794-<br />
802.<br />
[6] Awang, N., Baba, I. & Yam<strong>in</strong>, B.M. 2004.<br />
Synthesis and characterization <strong>of</strong> secbutylpropyldithiocarbamate<br />
compounds: crystal<br />
structures <strong>of</strong> Zn(s-BuPrDtc)2 and Cd(s-<br />
BuPrDTC)2. AJSTD 21(4):309-318.<br />
[7] Airoldi, C. & Oliveira, S. F. D. 1990. Adducts <strong>of</strong><br />
cadmium diethyldithiocarbamate with bidentate<br />
nitrogen ligands. Inorg. Chim. Acta 174: 103-<br />
108.<br />
[8] Nomura, R., Fujii, S., Takabe, A. & Matsuda, H.<br />
1989. Preparation <strong>of</strong> novel metal dithiocarbamate<br />
complexes conta<strong>in</strong><strong>in</strong>g ω-OH group. Stabilization<br />
effect <strong>of</strong> the OH group on the HNCS-Mt l<strong>in</strong>kage.<br />
Polyhedron 8(15): 1891-1896.<br />
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Titanium Dioxide Th<strong>in</strong> Film as Solar Photocatalyst for A Chlor<strong>in</strong>ated<br />
Degradation <strong>of</strong> Organics Contam<strong>in</strong>ate<br />
Muneer. M.Baabbad 1 ,Abdul Amir H.Kadhum 1 ,Abu Bakar Mohamad 1 ,<br />
Mohd S.Takriff 1 ,Kamaruzzaman. Sopian 2 .<br />
1 Faculty <strong>of</strong> Eng<strong>in</strong>eer<strong>in</strong>g and Built Eng<strong>in</strong>eer<strong>in</strong>g, Universiti Kebangsaan Malaysia<br />
43600 UKM, Bangi, Selangor Darul Ehsan, Malaysia.<br />
2 Solar Energy Research Institute (SERI) Universiti Kebangsaan Malaysia<br />
43600 UKM, Bangi, Selangor Darul Ehsan, Malaysia.<br />
Abstract<br />
This paper is review<strong>in</strong>g a Titanium dioxide th<strong>in</strong> film used <strong>in</strong> solar photocatalytic process. Solar photocatalytic<br />
technology is one <strong>of</strong> the major applications <strong>in</strong> the degradation <strong>of</strong> organic pollutants <strong>in</strong> water. <strong>The</strong><br />
heterogeneous photocatalytic distractions <strong>of</strong> organic contam<strong>in</strong>ates on th<strong>in</strong> film fixed bed reactor (TFFBR) is<br />
<strong>in</strong>vestigated. <strong>The</strong> degradation is studied us<strong>in</strong>g TiO 2 and also with different doped such as Pd and Fe 3+<br />
photocatalysts under solar light illum<strong>in</strong>ation. <strong>The</strong> th<strong>in</strong> films were prepared with the dip-coat<strong>in</strong>g technique<br />
(Sol-Gel) us<strong>in</strong>g titanium tetra-iospropoxide as a raw material for synthesis <strong>of</strong> th<strong>in</strong> film, followed by thermal<br />
treatment at 400C o . <strong>The</strong> sample characterized by X-ray diffraction, UV-vis spectroscopy, scann<strong>in</strong>g electron<br />
microscopy and atomic force microscopy. <strong>The</strong> photoactivity <strong>of</strong> various films were tested us<strong>in</strong>g different<br />
organic pollutants such as phenol and 4-chlorophenol (one <strong>of</strong> the most common water pollutants).<strong>The</strong><br />
photoeffc<strong>in</strong>ency obta<strong>in</strong>ed is approximately similar to that obta<strong>in</strong>ed us<strong>in</strong>g suspension. This was done for<br />
avoid<strong>in</strong>g many operational complications such as separation <strong>of</strong> the catalyst and cont<strong>in</strong>uous <strong>of</strong> process.<br />
Keywords: Titanium dioxide th<strong>in</strong> film (TiO 2), solar photocatalysis, organics contam<strong>in</strong>ates.<br />
Introduction<br />
Photocatalysis is the generally accepted term for a<br />
process <strong>in</strong> which light and a catalyst br<strong>in</strong>g about or<br />
accelerate a chemical reaction. <strong>The</strong> IUPAC<br />
def<strong>in</strong>ition states photocatalysis as ‘a catalytic<br />
reaction <strong>in</strong>volv<strong>in</strong>g light absorption by a catalyst or<br />
by a substrate’. In semiconduct<strong>in</strong>g photocatalysis,<br />
no energy is stored; <strong>in</strong>stead there is an acceleration<br />
<strong>of</strong> a reaction by a photon-assisted process. Titanium<br />
dioxide has been the practical photocatalyst [1] <strong>of</strong><br />
choice for a variety <strong>of</strong> reactions due to its high<br />
stability and oxidis<strong>in</strong>g power. It functions by<br />
absorb<strong>in</strong>g sub band-gap radiation, this generates an<br />
electron and positive hole that can migrate to the<br />
surface <strong>of</strong> the titania and promote oxidation and<br />
reduction reactions. Powders and th<strong>in</strong> films <strong>of</strong><br />
titania will photodegrade a wide range <strong>of</strong> organic<br />
chemicals <strong>in</strong> water [2-3]. Dur<strong>in</strong>g the last decades<br />
several efforts have been focused on improv<strong>in</strong>g<br />
decontam<strong>in</strong>ation <strong>of</strong> water [4] one <strong>of</strong> the most<br />
attractive options is the treatment by oxidation<br />
us<strong>in</strong>g a semiconductor, typically titanium dioxide,<br />
<strong>in</strong> comb<strong>in</strong>ation with solar irradiation. This process<br />
can destroy organic matter, transform<strong>in</strong>g organic<br />
carbon to CO2 and H2O employ<strong>in</strong>g just solar energy<br />
and a low cost non-toxic catalyst.<br />
Th<strong>in</strong> films <strong>of</strong> TiO2 on glass can be do<strong>in</strong>g by a<br />
number <strong>of</strong> different methods. It has been <strong>of</strong>ten<br />
prepared by expensive methods as pulsed laser<br />
deposition [5], reactive evaporation [6] and<br />
chemical vapour deposition [7-9]. <strong>The</strong> simplest and<br />
Low cost preparation methods are the sol-gel<br />
processes [10-14] <strong>in</strong>clud<strong>in</strong>g dip or sp<strong>in</strong>-coat<strong>in</strong>g [14]<br />
as the f<strong>in</strong>al step <strong>of</strong> preparation. <strong>The</strong> latter, along<br />
with the source <strong>of</strong> titania, also determ<strong>in</strong>es the gra<strong>in</strong><br />
size, structure, phase and density <strong>of</strong> sol-gel derived<br />
films [15-17]. Although titania th<strong>in</strong>-films have been<br />
proven to be effective <strong>in</strong> photo-oxidis<strong>in</strong>g organic<br />
substances, they can only do so under sub<br />
approximately 350 nm radiation. Its band-gap <strong>of</strong><br />
3.2 eV means that titania can use less than<br />
approximately 1% <strong>of</strong> the solar spectrum. Gerischer<br />
and Heller [18] have proposed that the activity <strong>of</strong> a<br />
photocatalyst is limited by the rate <strong>of</strong> electron<br />
transfer to oxygen on the surface <strong>of</strong> the catalyst.<br />
<strong>The</strong>re has been some research that suggests the<br />
modification <strong>of</strong> the TiO2 surface by Noble metals<br />
<strong>in</strong>creases the efficiency <strong>of</strong> electron transfer to<br />
oxygen, which <strong>in</strong> turn <strong>in</strong>creases the photooxidation<br />
efficiency. Some metals such as Pd and Fe +3 have<br />
also been doped <strong>in</strong>to titania <strong>in</strong> order to improve its<br />
physical and optical properties.<br />
Materials and Methods<br />
Sol-Gel synthesis process<br />
<strong>The</strong> TiO2 film was prepared us<strong>in</strong>g water; alcohol as<br />
solvent and different salts <strong>of</strong> metal oxide. In this<br />
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case, used titanium tetra-isopropoxide (TTIP) as a<br />
titanium dioxide precursor became easily TiO2 type<br />
due to rapid hydrolysis, and then, the acquired f<strong>in</strong>al<br />
products were divided <strong>in</strong> two parts, powder and<br />
solution, which are necessary as centrifugation for<br />
the separation <strong>of</strong> these to get a colloidal solution for<br />
TiO2 film [19] and procedure <strong>in</strong>dicated <strong>in</strong> Fig 1 (a)<br />
[20] .An aqueous solution molar ratio different<br />
accord<strong>in</strong>g <strong>of</strong> the type material films, show <strong>in</strong> the<br />
Table 1.<br />
Dip-coat<strong>in</strong>g<br />
<strong>The</strong> glass substrates were dipped <strong>in</strong> the solution by<br />
a locally constructed clipp<strong>in</strong>g mach<strong>in</strong>e. <strong>The</strong><br />
withdrawal rate used for the s<strong>in</strong>gle coated films was<br />
different speed show <strong>in</strong> the Table 1 .After each<br />
coat, the film was allowed to dry at room<br />
temperature for 10 m<strong>in</strong>. <strong>The</strong> procedure was<br />
repeated to obta<strong>in</strong> multiple coat<strong>in</strong>gs, Samples were<br />
annealed <strong>in</strong> a furnace at 400-500 C o for 1-3 h <strong>in</strong> air<br />
to fully decompose the precursor and obta<strong>in</strong><br />
crystall<strong>in</strong>e samples. <strong>The</strong> rate <strong>of</strong> heat<strong>in</strong>g and cool<strong>in</strong>g<br />
was 5 C o / m<strong>in</strong> [21-22].<br />
TTIP H2O Acid<br />
Alchol<br />
(a)<br />
Mix<strong>in</strong>g and Stirr<strong>in</strong>g<br />
Titania Sol<br />
Dip Coat<strong>in</strong>g<br />
Dry<strong>in</strong>g<br />
Bak<strong>in</strong>g<br />
TiO2 Th<strong>in</strong> Film<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
Characterization <strong>of</strong> TiO2 films us<strong>in</strong>g the sol–gel<br />
process<br />
<strong>The</strong> use <strong>of</strong> sol–gel multistep process led to the<br />
production <strong>of</strong> transparent nanocrystall<strong>in</strong>e TiO2 th<strong>in</strong><br />
films with excellent reproducibility, scratch<br />
resistance and adherence on the glass substrates.<br />
Also the low cost one technique produced opaque<br />
and thicker films with good uniformity, and with<br />
properties closely related to the start<strong>in</strong>g powder<br />
material. [23]. Right now, the research for<br />
improv<strong>in</strong>g the photocatalytic activity <strong>of</strong> TiO2<br />
ma<strong>in</strong>ly focus on the aspects as follows: dop<strong>in</strong>g <strong>of</strong><br />
metal ions, surface deposit<strong>in</strong>g <strong>of</strong> noble metal,<br />
recomb<strong>in</strong>ation <strong>of</strong> semiconductor, surface<br />
photosensitization and so on. Dop<strong>in</strong>g <strong>of</strong> metal ions<br />
has been largely employed with the aim to enhance<br />
the photocatalytic activity <strong>of</strong> TiO2 [24].Scann<strong>in</strong>g<br />
electron microscopy was employed to perform at<br />
first the surface characterization <strong>of</strong> the<br />
manufactured films. Crystall<strong>in</strong>ity <strong>of</strong> the TiO2 th<strong>in</strong><br />
film was anatase determ<strong>in</strong>ed by X-ray diffraction<br />
(XRD) us<strong>in</strong>g a diffract-meter with Cu K radiation,<br />
consisted with the literature [25]. <strong>The</strong> transmittance<br />
and absorbency <strong>of</strong> th<strong>in</strong> film were measured by UV–<br />
visible spectrophotometer.<br />
Figure 1: (a) preparation <strong>of</strong> TiO2 film by sol-gel, (b) Stages <strong>of</strong> the dip coat<strong>in</strong>g process.<br />
(b)<br />
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Degradation <strong>of</strong> pollutants (4- chlorophenols as<br />
example )<br />
<strong>The</strong> photodegradation <strong>of</strong> chlorophenols <strong>in</strong> aqueous<br />
solution has received considerable attention<br />
because these compounds are important xenobiotic<br />
micropollutants <strong>of</strong> the aquatic environment<br />
orig<strong>in</strong>at<strong>in</strong>g, for example, from <strong>in</strong>dustrial chemical<br />
synthesis. More specifically, 4-chlorophenol (4-CP)<br />
is used for the production <strong>of</strong> qu<strong>in</strong>izar<strong>in</strong> (a dye),<br />
cl<strong>of</strong>ibrate (a drug), chlorphenes<strong>in</strong> and dichlorophen<br />
(fungicides) [26]. <strong>The</strong>refore, several <strong>in</strong>vestigations<br />
<strong>of</strong> the photocatalytic decomposition <strong>of</strong><br />
chlorophenols us<strong>in</strong>g metal oxide semiconductors<br />
either <strong>in</strong> aqueous heterogeneous suspensions [27-<br />
31] or <strong>in</strong> an immobilized form [32-34] have been<br />
published. <strong>The</strong> k<strong>in</strong>etics <strong>of</strong> the photocatalytic 4-CP<br />
<strong>The</strong> generation <strong>of</strong> the observed reaction<br />
<strong>in</strong>termediates can be readily expla<strong>in</strong>ed though<br />
reaction schemes which <strong>in</strong>volve OH . radical attack<br />
<strong>of</strong> 4-CP, <strong>in</strong>itially to give the 4-chlorodihydroxycyclodienyl<br />
radical, lead<strong>in</strong>g on to the<br />
generation <strong>of</strong> 4-CC, HQ and BQ as <strong>in</strong>termediates to<br />
the eventual m<strong>in</strong>er- alisation <strong>of</strong> 4-CP. <strong>The</strong> primary<br />
oxidant appears to be surface absorbed OH radicals<br />
generated through the reaction between a<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
degradation have commonly been <strong>in</strong>terpreted as<br />
be<strong>in</strong>g <strong>in</strong>dicative <strong>of</strong> a Langmuir–H<strong>in</strong>shelwood- type<br />
mechanism <strong>in</strong> which the limitation <strong>of</strong> the 4-CP<br />
decomposition rate at higher pollutant<br />
concentrations is related to the extent <strong>of</strong> adsorption<br />
<strong>of</strong> the pollutant molecule on the TiO2 surface<br />
[30,35]. However, Cunn<strong>in</strong>gham et al. showed [31]<br />
that the observed adsorption constants <strong>of</strong><br />
chlorophenols on TiO2 <strong>in</strong> the dark differ from<br />
equivalent data obta<strong>in</strong>ed from the k<strong>in</strong>etic analysis<br />
<strong>of</strong> their photocatalytic degradation employ<strong>in</strong>g the<br />
same TiO2 particles under UVirradiation.<br />
<strong>The</strong> photo-oxidative m<strong>in</strong>eralisation <strong>of</strong> 4chloropheno<br />
4-CP) by oxygen and sensitised by<br />
TiO2, can be summarised as follows [36]:<br />
photogenerated valence-band hole and a surfacebound<br />
OH - or H2O group. Other sources <strong>of</strong> oxidant,<br />
which may also make a significant contribution,<br />
<strong>in</strong>clude OH . radicals derived from the oxygen<br />
reduction side <strong>of</strong> the photom<strong>in</strong>eralisation process<br />
and direct attack <strong>of</strong> the substrate by the<br />
photogenerated hole [37]. Fig. 2 illustrates a typical<br />
degradation reaction scheme for Degussa P25 TiO2<br />
power dispersions <strong>in</strong> acidic solution.<br />
Figure.2. Reaction scheme illustrat<strong>in</strong>g the likely mechanistic pathways to the formation <strong>of</strong> the major<br />
<strong>in</strong>termediates, 4-chlorocatechol (4-CC), hydroqu<strong>in</strong>one (HQ) and benzoqu<strong>in</strong>one (BQ), generated dur<strong>in</strong>g<br />
the photom<strong>in</strong>eralisation <strong>of</strong> 4-CP.<br />
Results and Discussion<br />
Synthesis -TiO2 films<br />
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<strong>The</strong> films were formed on the glass substrate by<br />
dipp<strong>in</strong>g <strong>in</strong>to the aged sol and then with- draw<strong>in</strong>g at<br />
a constant rate to obta<strong>in</strong> a uniform coat<strong>in</strong>g. <strong>The</strong><br />
solution rema<strong>in</strong>ed clear with no white TiO2 micro-<br />
particles precipitat<strong>in</strong>g out. Hydrochloric acid acts as<br />
a catalyst to complete the hydrolysis. <strong>The</strong> probable<br />
mechanism for the process is shown <strong>in</strong> Scheme 1.<br />
<strong>The</strong> titanium alkoxide is protonated <strong>in</strong> a rapid first<br />
step. This makes the Ti atom more electro- philic<br />
and susceptible to attack form the water [39].<br />
Withdraw <strong>of</strong> the glass-slide from the fluid-sol<br />
Mechanism <strong>of</strong> degradation process on th<strong>in</strong> film<br />
<strong>The</strong> photocatalytic oxidation driven by a large band<br />
gap semiconductor starts with the promotion <strong>of</strong><br />
electrons from the valence to the conduction band,<br />
creat<strong>in</strong>g an electron-hole couple. <strong>The</strong> electrons are<br />
removed by reaction with oxygen dissolved <strong>in</strong><br />
water and the cationic holes react either with OH -<br />
and/or H2O adsorbed at the semiconductor surface<br />
to form OH . radicals. Greater amounts <strong>of</strong> adsorbed<br />
OH - and/or H2O generate a concomitant <strong>in</strong>crease <strong>in</strong><br />
the amount <strong>of</strong> hydroxyl radicals favor<strong>in</strong>g thus the<br />
photodegradation process. Tak<strong>in</strong>g <strong>in</strong>to account the<br />
heterogeneous photocatalytic mechanism <strong>of</strong> a th<strong>in</strong><br />
film TiO2 catalyst, the follow<strong>in</strong>g steps typically<br />
take place [38]: (i) light absorption on the<br />
photocatalytic surface (ii) chemical transformation<br />
<strong>of</strong> the molecule while several reaction surface sites<br />
are visited (iii) desorption to the liquid phase.<br />
Degradation <strong>of</strong> chlor<strong>in</strong>ated <strong>of</strong> organics<br />
contam<strong>in</strong>ate<br />
<strong>The</strong> use <strong>of</strong> sol–gel multistep process led to the<br />
production <strong>of</strong> transparent nanocrystall<strong>in</strong>e TiO2 th<strong>in</strong><br />
films with excellent reproducibility, scratch<br />
Scheme 1: illustrate the steps <strong>of</strong> Synthesis -TiO2 film<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
produces a transparent film due to the evaporation<br />
<strong>of</strong> the solvent and hydrolysis <strong>of</strong> [Ti-(Oi Pr)4].<br />
Dur<strong>in</strong>g dipp<strong>in</strong>g, aggregation, gelation and dry<strong>in</strong>g<br />
occurs <strong>in</strong> seconds to m<strong>in</strong>utes, rather than days as <strong>in</strong><br />
bulk sol-gel systems [40]. Anneal<strong>in</strong>g <strong>of</strong> the film<br />
removed any rema<strong>in</strong><strong>in</strong>g solvent and the structure is<br />
stiffened i.e. a Ti-O-Ti network formed by removal<br />
<strong>of</strong> the alkoxy and hydroxyl groups to produce an<br />
anatase th<strong>in</strong> film. It was noted that the most<br />
photocatalyically active films were formed by dip-<br />
coat<strong>in</strong>g 24 h after the <strong>in</strong>itial hydrolysis.<br />
resistance and adherence on the glass substrates.<br />
<strong>The</strong> photocatalytic activities <strong>of</strong> all <strong>of</strong> the films were<br />
determ<strong>in</strong>ed by photodegradation <strong>of</strong> th<strong>in</strong> dip-coated<br />
film <strong>of</strong> chlor<strong>in</strong>ated <strong>of</strong> organics contam<strong>in</strong>ates. <strong>The</strong><br />
most outstand<strong>in</strong>g feature with dip-cota<strong>in</strong>g method<br />
is that photocatalytic activity is higher when glass<br />
is used as support. Some typical results are reported<br />
<strong>in</strong> the Table 1.<br />
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Table 1 Illustrate Material <strong>of</strong> Sol-Gel method and Degradation <strong>of</strong> some Chlor<strong>in</strong>ated Organics contam<strong>in</strong>ate photocatalytic degradation <strong>of</strong> the 4-chlorophenol concentration as a<br />
function <strong>of</strong> exposure time to the solar irradiation and us<strong>in</strong>g TiO2 th<strong>in</strong> films as catalysts<br />
No Type <strong>of</strong><br />
Th<strong>in</strong><br />
TTIP*<br />
Mol<br />
Catalyst<br />
Mol<br />
Solvent<br />
Mol<br />
H2O<br />
Mol<br />
Acid<br />
Mol<br />
Film<br />
thickne<br />
Dipcoat<strong>in</strong>g<br />
Organic<br />
degradation<br />
Time <strong>of</strong><br />
degradation<br />
Organic<br />
degradation<br />
C/C0<br />
%<br />
Ref<br />
.<br />
Film<br />
ss speed<br />
m<strong>in</strong><br />
%<br />
nm cm/m<strong>in</strong><br />
1 TiO2 0.1 0.4 0.1 Hcl<br />
0.008<br />
600 10 4-chlorophenol 180 - 24 41<br />
2 TiO2 titanium<br />
<strong>in</strong>n-<br />
sulfonicacid 500- 2 3,5-dichlorophenol 1600 100 - 42<br />
butoxide<br />
1.72gm<br />
butanol<br />
600<br />
3<br />
4<br />
5-<br />
Fe +3 / 1 Fecl EtOH<br />
TiO2<br />
1 20<br />
Pd/ TiO2 1 Pd ethyl<br />
(NO3)2 alcohol<br />
0.15 7.6<br />
TiO2 0.1 isopropyl<br />
alcohol<br />
0.4<br />
20 acetic acid 4,<br />
0.1<br />
HNO3<br />
0.5<br />
HCl 1000-<br />
1600<br />
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490 6.9 Dichloroacetic acid 150 80 - 43<br />
180 2.4 Phenol 1440 83 - 44<br />
4 1,1_-dimethyl-<br />
4,4_-bipyidium<br />
dichloride<br />
900 95 - 46
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January 24, 2009<br />
After 3 h <strong>of</strong> concentrated solar irradiation, the f<strong>in</strong>al<br />
dissolved concentration <strong>of</strong> 4-chlorophenol is 24%<br />
<strong>of</strong> its <strong>in</strong>itial for the TiO2 immobilized catalysts. This<br />
means that TiO2 immobilized catalysts high<br />
photoefficiency [41]. A.Mills & J.Wang [36]<br />
reported the temporal variations <strong>in</strong>: [4-CP], [4-CC],<br />
[HQ], [CO2] and it appears likely that the reaction<br />
scheme illustrated <strong>in</strong> Fig. 3 is also applicable to<br />
TiO2 films <strong>of</strong> Degussa P25, that is, there is no<br />
major difference <strong>in</strong> the overall degradation reaction<br />
mechanism for films or dispersions <strong>of</strong> the same<br />
TiO2 source material (Degussa P25 <strong>in</strong> this case).<br />
Photocatalytic experiments took place to evaluate<br />
the films as a possible material for 3,5dichlorophenol<br />
(3,5-DCP) pollutant purification<br />
from water. Each experiment <strong>in</strong>cluded complete<br />
decomposition (100%) <strong>of</strong> the b 3, 5-DCP but at<br />
long time due to films are endowed with a higher<br />
real surface extension, which readily favors the<br />
photodecomposition process .In fact, such a surface<br />
not only permits the adsorption <strong>of</strong> a greater number<br />
<strong>of</strong> pollutant molecules, but also creates a rough<br />
environment where multiple light reflection can<br />
occur, thus considerable <strong>in</strong>creas<strong>in</strong>g the amount <strong>of</strong><br />
the adsorbed photons [42] .<strong>The</strong> titania films<br />
functionalized with iron cations used model <strong>of</strong><br />
Dichloroacetic acid (DCA) degradation. Fe/TiO2<br />
film <strong>in</strong> presence <strong>of</strong> DCA and oxygen lead to proton<br />
release due to degradation <strong>of</strong> the organic molecules<br />
[43]. <strong>The</strong> Fe/Ti films are more effective<br />
photocatalysts with s<strong>in</strong>gle coated and it give<br />
degradation efficiency 80 %. <strong>The</strong> photodegradation<br />
<strong>of</strong> phenol us<strong>in</strong>g the film modified with palladium<br />
was superior to that achieved with the pure titanium<br />
film [44]. However, <strong>in</strong> the case <strong>of</strong> a film, the<br />
particles are attached to the surface <strong>of</strong> a solid<br />
substrate, without the occurrence <strong>of</strong> aggregates, as<br />
<strong>in</strong> the case <strong>of</strong> a suspension. Probably, <strong>in</strong> the case <strong>of</strong><br />
th<strong>in</strong> films, the substrate–catalyst repulsion due to<br />
the dissociation <strong>of</strong> the −OH groups present on the<br />
titania surface is negligible, consider<strong>in</strong>g that the<br />
catalyst mass is small. Thus, the dom<strong>in</strong>ant factor <strong>in</strong><br />
the photocatalytic process <strong>in</strong>volv<strong>in</strong>g th<strong>in</strong> films is<br />
mass transport [45]. <strong>The</strong> photodegradations <strong>of</strong> 1,1dimethyl-4,4-bipyidium<br />
dichloride (Paraquat) with<br />
coat<strong>in</strong>g time are compared. First, <strong>in</strong> case <strong>of</strong> the film<br />
atta<strong>in</strong>ed from the sol–gel method the Paraquat<br />
decomposition slowly <strong>in</strong>creased with an <strong>in</strong>crease <strong>of</strong><br />
coat<strong>in</strong>g time. In particular, the conversion <strong>of</strong><br />
Paraquat was above 90% with four-time coat<strong>in</strong>g<br />
after 25 h[46].<br />
Conclusions<br />
<strong>The</strong> use <strong>of</strong> a sol–gel multistep process allowed<br />
produc<strong>in</strong>g th<strong>in</strong> TiO2 films with an excellent<br />
adherence onto glass substrates obta<strong>in</strong>ed by us<strong>in</strong>g<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
commercial titanium tetra-isopropoxide (TTIP).<br />
<strong>The</strong> results showed that the films possessed good<br />
photocatalytic activity for the degradation <strong>of</strong><br />
organics contam<strong>in</strong>ate as a typical photocatalytic<br />
reaction <strong>in</strong> liquid–solid systems. <strong>The</strong> modified<br />
films (Pd and Fe 3+ / TiO2) prepared by the sol–gel<br />
route and deposited <strong>in</strong> film form on the surface <strong>of</strong><br />
glass exhibited high photocatalytic activity and also<br />
TiO2 film. S<strong>in</strong>ce the use <strong>of</strong> the fixed catalyst avoids<br />
many operational complications for separation <strong>of</strong><br />
the powder catalyst, this represents a great<br />
advantage towards the application <strong>of</strong> this<br />
technology.<br />
Acknowledgements<br />
<strong>The</strong> authors greatly a acknowledge to Solar Energy<br />
Research Institute (SERI) Universiti Kebangsaan<br />
Malaysia for its f<strong>in</strong>ancial support (UKM-RS-02-<br />
FRGS0004-20007).<br />
References<br />
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35.<br />
[2] Hager, S., Bauer R.& Kudielka, G.<br />
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Chemosphere 41:1219–1225.<br />
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Preparation <strong>of</strong> epitaxial TiO2 films by pulsed<br />
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[12] Hattori, A. & Tada, H.2001. High<br />
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[13] Smirnova,N. , Eremenko, A, Gayvoronskij,<br />
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[19] Kang, M.2002. Preparation <strong>of</strong> TiO2<br />
photocatalyst film and its catalytic<br />
performance for 1,1-dimethyl-4,4-<br />
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bipyidiumdichloride decomposition. Applied<br />
Catalysis B: Environmental 37:187–196.<br />
[20] Jung, S.-C.2008.photocatalytic activites and<br />
specific surface area <strong>of</strong> TiO2 films prepared<br />
by CVD and sol-gel method .korean<br />
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[21] Rampaul, A., Park<strong>in</strong>, I.P., O’Neill, S. A.,<br />
DeSouza, J., Mills, A., Elliott<br />
,N.2003.Titania and tungsten doped titania<br />
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[22] Strawbridge, I. &. James, P. F.1986. Th<strong>in</strong><br />
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[23] Arabatzis, I.M., Antonaraki, S.,<br />
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Falaras, P. 2002.Preparation,<br />
characterization<br />
and photocatalytic activity <strong>of</strong><br />
nanocrystall<strong>in</strong>eth<strong>in</strong> film TiO2 catalysts<br />
towards 3,5-dichlorophenol. Journal <strong>of</strong><br />
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[24] Yua, H., Lia, X.J, Zhenga, S.J. & Xua, W.<br />
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film non-uniformly doped by Ni. Materials<br />
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[25] Yu, J.G., Zhao, X.J, Zhao,<br />
Q.N.2001.Photocatalytic activity <strong>of</strong><br />
nanometer TiO2 th<strong>in</strong> films prepared by the<br />
sol-gel method.Mater.Chem.Phys., 69:25-29.<br />
[26] Oudjehani, K., Boule, P.1992.<br />
Photoreactivity <strong>of</strong> 4-chlorophenol <strong>in</strong> aqueous<br />
solution. J. Photochem. Photobiol. A<br />
68:363–373.<br />
[27] Al-Sayyed, G., D-Oliveira, J.C., Pichat,<br />
P.1991. Semiconductorsensitized<br />
photodegradation <strong>of</strong> 4-chlorophenol <strong>in</strong><br />
water.J. Photochem. Photobiol. A 58: 99–<br />
114.<br />
[28] Sehili, T., Boule, P., Lemaire, J., 1989.<br />
Photocatalysed Transformation <strong>of</strong><br />
chloroaromatic derivatives on z<strong>in</strong>c oxide,<br />
III:chlorophenols. J. Photochem. Photobiol.<br />
A 50:117–127.<br />
[29] Barbeni, M., Pramauro, P., Pelizzetti, E.,<br />
Borgarello, E., Gra¨tzel, M., Serpone,<br />
N.1984. Photodegradation <strong>of</strong> 4-chlorophenol<br />
catalyzed by titanium dioxide particles.<br />
Nouv. J. Chim. 8:547–550.<br />
[30] Stafford, U., Gray, K.A., Kamat, P.V.1994.<br />
Radiolytic and TiO2-assisted photocatalytic<br />
degradation <strong>of</strong> 4-chlorophenol a comparative<br />
study. J. Phys. Chem. 98:6343–6351.<br />
[31] Cunn<strong>in</strong>gham, J., Sedlak, P.1994.<br />
Interrelationships between pollutant<br />
concentration, extent <strong>of</strong> adsorption, TiO2-<br />
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sensitized removal, photon flux and levels <strong>of</strong><br />
electron or hole trapp<strong>in</strong>g additives, 1.<br />
Aqueous monochlorphenol-TiO2 (P25)<br />
suspensions. J. Photochem. Photobiol. A 77:<br />
255–263.<br />
[32] Al-Ekabi, H., Serpone, N., Pelizzetti, E.,<br />
M<strong>in</strong>ero, C., Fox, R.B., Draper, R.B. 1989.<br />
K<strong>in</strong>etic studies <strong>in</strong> heterogeneous<br />
semiconductor particles. Prep. Am. Chem.<br />
Soc. Environ. Chem. 27:528–534.<br />
[33] H<strong>of</strong>stadler, K., Bauer, R., Novalic, S., Heisler,<br />
G.1994. New reactor design for<br />
photocatalytic waste-water treatment with<br />
TiO2 immobilized on fused-silica glassfibers<br />
photom<strong>in</strong>eralization <strong>of</strong> 4chlorophenol.<br />
Environ. Sci. Technol.<br />
28:670–674.<br />
[34] V<strong>in</strong>odgopal, K., Stafford, U., Gray, K.A.,<br />
Kamat, P.V.1994. Electrochemically assisted<br />
photocatalysis. 2. <strong>The</strong> role <strong>of</strong> oxygen and<br />
reaction <strong>in</strong>termediates <strong>in</strong> thr degradation <strong>of</strong><br />
4- chlorophenol on immobilized TiO2<br />
particulate films. J.Phys. Chem. 98: 6797–<br />
6803.<br />
[35] Al-Sayyed, G., D-Oliveira, J.C., Pichat,<br />
P.1991. Semiconductor sensitized<br />
photodegradation <strong>of</strong> 4-chlorophenol <strong>in</strong><br />
water.J. Photochem. Photobiol. A 58: 99–<br />
114.<br />
[36] Mills, A. & Wang,<br />
J.1998.Photom<strong>in</strong>eralisation <strong>of</strong> 4chlorophenol<br />
sensitised by TiO2 th<strong>in</strong> films. J.<br />
<strong>of</strong> Photochemistry and Photobiology A:<br />
Chemistry 118: 53-63.<br />
[37] H<strong>of</strong>fmann, M.R., Mart<strong>in</strong>, S.T., Choi, W.&<br />
Bahnemann, D.W.1995.Environmental<br />
Applications <strong>of</strong> Semiconductor<br />
Photocatalysis, Chem. Rev. 95:69-96.<br />
[38] Serpone, N., Sal<strong>in</strong>aro, A., Emel<strong>in</strong>e, A. &<br />
Ryabchuk, V.2000.Turnovers and<br />
photocatalysis: A mathematical description,<br />
Journal <strong>of</strong> Photochemistry and Photobiology<br />
A: Chemistry 130: 83-94.<br />
[39] Sopyan, I., Watanabe, M., Murasawa, S.,<br />
Hushimoto, K., Fujishima, A. 1996. Efficient<br />
TiO2 Powder and Film Photocatalysts with<br />
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Rutile Crystal Structure,Chem. Lett. 25: 69-<br />
71.<br />
[40] Br<strong>in</strong>ker C.J., Scherer G.W. 1990.<strong>The</strong> Physics<br />
and Chemistry <strong>of</strong> Sol-Gel Process<strong>in</strong>g,<br />
Academic Press, New York.<br />
[41] Gelover, S., Mondragón, P., Jiménez,<br />
A.2004. Titanium dioxide sol-gel deposited<br />
over glass and its applicationas a<br />
photocatalyst for water decontam<strong>in</strong>ation.<br />
Journal <strong>of</strong> Photochemistry and Photobiology<br />
A: Chemistry 165 (2004) 241–246.<br />
[42] Arabatzis, I.M., Antonaraki, S.,<br />
Stergiopoulos, T., Hiskia, A.,<br />
Papaconstant<strong>in</strong>ou E. , Bernard, M.C.,<br />
Falaras, P. 2002.Preparation,<br />
characterization<br />
and photocatalytic activity <strong>of</strong><br />
nanocrystall<strong>in</strong>eth<strong>in</strong> film TiO2 catalysts<br />
towards 3,5-dichlorophenol. Journal <strong>of</strong><br />
Photochemistry and Photobiology A:<br />
Chemistry 149: 237–245.<br />
[43] Smirnova, N., Eremenko, A. & Rus<strong>in</strong>a,<br />
O.2001.Synthesis and characterization <strong>of</strong><br />
photocatalytic porous Fe +3 /TiO2 Layers on<br />
glass. Journal Sol-Gel Science and<br />
Technology 21:109-113.<br />
[44] Cristante, V.M. , Jorge, S. M.A. , Valente,<br />
J. P.S., Saeki, M. J., Florent<strong>in</strong>o, A.O.,<br />
Padilha, P. M. 2007.TiO2 films<br />
organ<strong>of</strong>unctionalized with 2-am<strong>in</strong>othiazole<br />
ligand and adsorbed Pd (II) ions applied <strong>in</strong><br />
the photocatalytic degradation <strong>of</strong> phenol <strong>in</strong><br />
an aqueous medium. Th<strong>in</strong> Solid Films 515:<br />
5334–5340.<br />
[45] Ahmed, S., Jones, C. E., Kemp, T. J. &<br />
Unw<strong>in</strong>, P. R.1999.<strong>The</strong> Role <strong>of</strong> Mass<br />
Transport <strong>in</strong> Solution Photocatalysis at a<br />
Supported Titanium Dioxide Surface, Phys.<br />
Chem. Chem. Phys.1:5229 – 5233.<br />
[46] Kang, M.2002. Preparation <strong>of</strong> TiO2<br />
photocatalyst film and its catalytic<br />
performance for 1, 1-dimethyl-4, 4bipyidium<br />
dichloride decomposition.<br />
Applied Catalysis B: Environmental 37:187–<br />
196.<br />
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ISBN : 978 – 979 – 19201 – 0 – 0<br />
Biological Activity <strong>of</strong> New Schiff Bases Derived From Thiophene and <strong>The</strong>ir<br />
Transition Metal Complexes<br />
Md. Uwaisulqarni Osman 1* , M. Ibrahim M. Tahir 2 , Karen A. Crouse 2 , A.M. Ali 3<br />
1 Department <strong>of</strong> Chemical Sciences, Faculty <strong>of</strong> Science and Techology, Universiti Malaysia Terengganu, 21030<br />
Kuala Terengganu, Terengganu Darul Iman, Malaysia.<br />
2 Department <strong>of</strong> Chemistry, Faculty <strong>of</strong> Science,Universiti Putra Malaysia,<br />
43400 UPM Serdang, Malaysia<br />
3 Laboratory <strong>of</strong> Molecular and Cell Biology, Institute <strong>of</strong> Bioscience, Universiti Putra Malaysia, 43400 Serdang,<br />
Selangor, Malaysia<br />
*uwais@umt.edu.my<br />
Introduction<br />
Abstract<br />
A new Schiff base formed from S-benzyldithiocarbazate (SBDTC) with selected aldehyde conta<strong>in</strong><strong>in</strong>g a<br />
thiophene r<strong>in</strong>g namely, thiophene-2-carbaldehyde (NS’) <strong>in</strong> 95 % <strong>of</strong> ethanol have been synthesized.<br />
Complexes <strong>of</strong> Cobalt(III), Nickel(II), Copper(II), Z<strong>in</strong>c(II) and Cadmium(II) with this Schiff base was<br />
prepared. <strong>The</strong> Schiff base and their metal complexes were evaluated for their cytotoxic and<br />
antimicrobial activities. Cytotoxic screen<strong>in</strong>g was carried out aga<strong>in</strong>st Human ovarian cancer cells<br />
(CaOV-3), Human breast carc<strong>in</strong>oma cells with negative estrogen receptor (MDA-MB-231) and Human<br />
liver carc<strong>in</strong>oma cells (HEP-G2). Antimicrobial screen<strong>in</strong>g was carried out aga<strong>in</strong>st four bacteria and three<br />
fungi.<br />
Keywords: Schiff Base, metal complexes, S-benzyldithiocarbazate (SBDTC), Cytotoxic, Antimicrobial,<br />
thiophene-2-carbaldehyde<br />
Many researchers had been carried on Schiff<br />
bases and their complexes [1, 2, 3, 4, 5] where, Schiff<br />
bases are compounds with structure <strong>of</strong> –C=N-<br />
(azometh<strong>in</strong>e group) which can be synthesized<br />
through condensation reaction between primary<br />
am<strong>in</strong>es and active carbonyl groups. Usually,<br />
bidentate Schiff base can coord<strong>in</strong>ate with various<br />
transition metals through –C=N- (azometh<strong>in</strong>e group)<br />
and –C=S (mercaptide group) [6] and gives solid<br />
metal complexes together with various geometry<br />
depends on the nature <strong>of</strong> the metals. <strong>The</strong>ir flexibility<br />
<strong>in</strong> chelat<strong>in</strong>g with transition metals had emerged the<br />
knowledge on relationship between coord<strong>in</strong>ation<br />
chemistry and their <strong>in</strong>terest<strong>in</strong>g and important<br />
properties e.g antimicrobial, antifungal and<br />
anticancer [6,7, 8, 9, 10].<br />
<strong>The</strong> present study was under taken to<br />
<strong>in</strong>vestigate more on biological activity <strong>of</strong> the Schiff<br />
base derived from the S-benzyldithiocarbazate<br />
(SBDTC) with thiophene-2-carbaldehyde (NS’).<br />
However, all physico-chemical analyses to confirm<br />
the structures had been done us<strong>in</strong>g IR, magnetic, 1 H<br />
and 12 C NMR measurements, thermogravimetric<br />
analysis, CHNS analyses and X-Ray Crystallography.<br />
Furthermore, all the results are not <strong>in</strong>cluded <strong>in</strong> the<br />
present study.<br />
Materials and Methods<br />
Cytotoxic Assay<br />
All the Schiff base and metal complexes were tested<br />
to determ<strong>in</strong>e their cytotoxicity aga<strong>in</strong>st CaOV-3<br />
(Human Ovarian Cancer cells), MDA-MB-231<br />
(Human breast carc<strong>in</strong>oma cells with negative<br />
estrogen receptor) and HEP-G2 (Human Liver<br />
carc<strong>in</strong>oma cells) cell l<strong>in</strong>es at Faculty <strong>of</strong> Medic<strong>in</strong>e and<br />
Health Science, Universiti Putra Malaysia. <strong>The</strong> cell<br />
l<strong>in</strong>es were obta<strong>in</strong>ed from the National Cancer<br />
Institute, U.S.A. <strong>The</strong> cells were cultured <strong>in</strong> RPMI-<br />
1640 (Sigma) medium supplemented with 10% fetal<br />
calf serum. Generally, cells are separated <strong>in</strong>to s<strong>in</strong>glecell<br />
suspensions by a gentle pipett<strong>in</strong>g action, then<br />
counted us<strong>in</strong>g trypan-blue exclusion on a<br />
hemacytometer, After count<strong>in</strong>g, dilutions are made to<br />
give the appropriate cell densities for <strong>in</strong>oculation<br />
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onto the microtiter plates. A 100 µL aliquot <strong>of</strong><br />
complete medium is added to cell-free wells. Cells<br />
from all cell l<strong>in</strong>es are counted, diluted and <strong>in</strong>oculated<br />
onto microculture plates. <strong>The</strong> microtiter plates<br />
conta<strong>in</strong><strong>in</strong>g the cells are pre<strong>in</strong>cubated for<br />
approximately 24 hours at 37°C to allow stabilization<br />
prior to addition <strong>of</strong> drug. After that, for <strong>in</strong>itial<br />
screen<strong>in</strong>g <strong>of</strong> pure compounds, each agent is rout<strong>in</strong>ely<br />
tested at five 10 fold dilution, start<strong>in</strong>g from a<br />
maximum concentration <strong>of</strong> 10 -4 M and immediately<br />
100 µL aluquots <strong>of</strong> each dilution are added to the<br />
appropriate microtiter plates wells. Dur<strong>in</strong>g<br />
development <strong>of</strong> these procedures, drug <strong>in</strong>cubation<br />
time was 4 days at 37°C <strong>in</strong> an atmosphere <strong>of</strong> 5% CO2<br />
and 100% relative humidity. <strong>The</strong> plates were then<br />
assayed for cytotoxicity us<strong>in</strong>g the microtitration <strong>of</strong> 3-<br />
(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium<br />
bromide (MTT) assay (Sigma,) [11]. Controls that<br />
conta<strong>in</strong>ed only cells were <strong>in</strong>cluded for each sample.<br />
Cytotoxicity (CD50) was expressed as the<br />
concentration that reduced the absorbance <strong>of</strong> treated<br />
cells by 50% with reference to the control, untreated<br />
cells. Tamoxifen were used as the standard control.<br />
Qualitative Antimicrobial Assay<br />
Eight pathogenic microbials were used to test the<br />
biological properties <strong>of</strong> the Schiff bases and their<br />
complexes at Laboratory <strong>of</strong> Molecular and Cell<br />
Biology, Institute <strong>of</strong> Bioscience, Universiti Putra<br />
Malaysia. <strong>The</strong>y were Methicill<strong>in</strong> resistant<br />
staphylococcus (MRSA), Bacillus subtilis wild type<br />
(B29), Subtilis mutant (mutant defective DNA repair,<br />
B28), Pseudomonas aerug<strong>in</strong>osa (60690), Candida<br />
albicans (C.A.), Aspergillus ochraceous (398),<br />
Saccharomyces cerevisiae ( 20341) and Candida<br />
lypolytica (2075). Antimicrobial activity <strong>of</strong> each<br />
sample was qualitatively determ<strong>in</strong>ed by a modified<br />
disc diffusion method [12]. A lawn <strong>of</strong><br />
microorganisms was prepared by pipett<strong>in</strong>g and<br />
evenly spread<strong>in</strong>g <strong>in</strong>oculum (10 -4 cm 3 , adjusted<br />
turbidometrically to 10 5 – 10 6 cfu/cm 3 (cfu: colony<br />
form<strong>in</strong>g units) on to agar set <strong>in</strong> Petri dishes, us<strong>in</strong>g<br />
Nutrient agar (NA) for the bacteria and potato<br />
dextrose agar (PDA) for fungi. Whatman No. 1 filter<br />
paper discs <strong>of</strong> 6mm diameter were impregnated with<br />
stock solution <strong>of</strong> the compound (100mg/cm 3 ) and<br />
dried under sterile conditions. <strong>The</strong> dried discs were<br />
then placed on the previously <strong>in</strong>oculated agar surface.<br />
<strong>The</strong> plates were <strong>in</strong>verted and <strong>in</strong>cubated for 24 hours<br />
at 30°C for bacteria and 37°C for fungi.<br />
Antimicrobial activity was <strong>in</strong>dicated by the presence<br />
<strong>of</strong> clear <strong>in</strong>hibition zones around the discs.<br />
Commercially available Streptomyc<strong>in</strong> (Sigma) was<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
used for the antibacterial control while Nystat<strong>in</strong><br />
(Sigma) was used as the antifungal control.<br />
Quantitative Antimicrobial Assay<br />
Compounds that showed positive (diameter >15 mm)<br />
anti-microbial <strong>in</strong>hibition with the disc diffusion assay<br />
were subjected to the broth dilution method for the<br />
quantitative measurement <strong>of</strong> microbiostatic<br />
(<strong>in</strong>hibitory) activity as described previously [13]. <strong>The</strong><br />
lowest concentration that completely <strong>in</strong>hibited visible<br />
microbial growth was recorded as the m<strong>in</strong>imum<br />
<strong>in</strong>hibitory concentration (MIC, µg/cm 3 ).<br />
Streptomyc<strong>in</strong> and Nystat<strong>in</strong> were used as controls<br />
standard<br />
Results and Discussion<br />
Cytotoxic Assay<br />
All the Schiff bases and complexes were evaluated<br />
<strong>in</strong>-vitro us<strong>in</strong>g CaOV-3 (Human ovarian cancer cells<br />
), MDA-MB-231 (Human breast carc<strong>in</strong>oma cells with<br />
negative estrogen receptor) and HEP-G2 (Human<br />
liver carc<strong>in</strong>oma cells) to see if they had potential use<br />
as anticancer agents. Measurement for cytotoxicity<br />
was <strong>in</strong> CD50, where CD50 refers to “cytotoxic dose at<br />
50%” i.e. the concentration required to reduce growth<br />
<strong>of</strong> cancer cells by 50%. Compounds hav<strong>in</strong>g CD50<br />
values <strong>of</strong> less than 5 µg cm -3 are considered highly<br />
active and 5-10 µg cm -3 are moderately active.<br />
Compounds with CD50 from 10-20 µg cm -3 are<br />
classified as hav<strong>in</strong>g weak cytotoxic activity while<br />
those compounds hav<strong>in</strong>g CD50 values <strong>of</strong> more than<br />
20 µg cm -3 are considered as <strong>in</strong>active. <strong>The</strong> results<br />
show that all screen<strong>in</strong>g results aga<strong>in</strong>st selected cancer<br />
cells are shown <strong>in</strong> Table 1. All the Schiff bases and<br />
complexes were not active aga<strong>in</strong>st all the cancer cell<br />
l<strong>in</strong>es tested.<br />
<strong>The</strong> cytotoxic potential <strong>of</strong> the compounds<br />
conta<strong>in</strong><strong>in</strong>g thiophene is well supported by other<br />
researchers [14-17]. An earlier study with the related<br />
compounds [18], SB2ATP, SB3ATP, Co(SB2ATP)2,<br />
Cu(SB2ATP)2, Cu(SB3ATP)2, Zn(SB2ATP)2 and<br />
Cd(SB2ATP)2 showed high activity toward human<br />
breast carc<strong>in</strong>oma with positive estrogen receptor<br />
(MCF-7). Unfortunately, comparison with human<br />
breast carc<strong>in</strong>oma with positive estrogen receptor<br />
(MCF-7) was unable to be done as cells were<br />
unavailable.<br />
<strong>The</strong> results showed that the Schiff bases<br />
synthesized by condensation <strong>of</strong> SBDTC with furyl<br />
groups (5-methyl-2-furyldehyde and 2-furyl-<br />
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methylketone) [6] were highly active aga<strong>in</strong>st CEM-<br />
SS (Human cell T-lymphoblastic leukemia) with a<br />
CD50 value <strong>of</strong> 2.0 mg cm -3 when chelated to Zn(II)<br />
[Zn(NS)2]. Furthermore, [Cd(NS)2] was moderately<br />
active with a CD50 value <strong>of</strong> 4.95 mg cm -3 but none <strong>of</strong><br />
the compounds were found to be active aga<strong>in</strong>st HT-<br />
29 (Human colon adenocarc<strong>in</strong>oma cells).<br />
Unfortunately, comparison with CEM-SS (Human<br />
cell T-lymphoblastic leukemia) and HT-29 (Human<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
colon adenocarc<strong>in</strong>oma cells) was unable to be done<br />
as those cells were unavailable also.<br />
It is clear that small changes <strong>in</strong> the backbone<br />
<strong>of</strong> the structure <strong>of</strong> a ligand, with benzyl r<strong>in</strong>g, were<br />
unable to br<strong>in</strong>g about great changes <strong>in</strong> the ability <strong>of</strong><br />
the complex to act as an anticancer agent aga<strong>in</strong>st<br />
different cell l<strong>in</strong>es. However, it is hoped that some<br />
series <strong>of</strong> complexes would show activity with cancer<br />
cell l<strong>in</strong>es that were not tested, i.e MCF-7, CEM-SS<br />
and HT-29.<br />
Table 1 Screen<strong>in</strong>g test aga<strong>in</strong>st CaOV-3 (Human Ovarian Cancer cells ), MDA-MB-231 (Human breast carc<strong>in</strong>oma<br />
cells with negative estrogen receptor) and HEP-G2 (Human Liver carc<strong>in</strong>oma cells)<br />
Antimicrobial Assay<br />
CD50 (µg/ml)<br />
Compounds<br />
MDA-<br />
CaOV-3 MB-231 HEP-G2<br />
NS' - - -<br />
Co(NS')3 - - -<br />
Ni(NS')2 - - -<br />
Cu(NS')2. H2O - - -<br />
Zn(NS')2 - - -<br />
Cd(NS')2<br />
Standard<br />
- - -<br />
Tamoxifen 1.0 2.3 3.5<br />
- <strong>in</strong>active<br />
<strong>The</strong> qualitative results are shown <strong>in</strong> Table 2. it was<br />
clearly seen that after chelation, the antimicrobial<br />
activity decreased for NS’ aga<strong>in</strong>st B29, where the<br />
activity was similar. Among all the metal complexes,<br />
only [Cu(NS’)2.H2O] complexes showed weak<br />
activities aga<strong>in</strong>st more than two types <strong>of</strong> microbes.<br />
None <strong>of</strong> the compounds showed any antimicrobial<br />
activity towards S.T and 60690. Ni(NS’)2 showed<br />
Table 2 Qualitative antimicrobial assay results a (diameter <strong>in</strong> mm)<br />
weak activity aga<strong>in</strong>st 398. F<strong>in</strong>ally B29 was less<br />
resistant with NS’ complexes. It can be deduced that<br />
the presence <strong>of</strong> a bulky group can enhance the<br />
activity. <strong>The</strong> same pattern has also been observed for<br />
amoebicidal activity <strong>of</strong> palladium(II) complexes<br />
derived from thiophene-2-carboxaldehyde<br />
thiosemicarbazones [26]. However, a series <strong>of</strong><br />
thiophene derived dithiocarbazate Schiff bases and its<br />
complexes can enhance the antimicrobial activity<br />
only after chelation with Cu 2+ .<br />
Bacterial stra<strong>in</strong>s Fungal Stra<strong>in</strong>s<br />
Sample MRSA B29 S.Typhimurium 60690 C.A 398 20341<br />
NS' - 9<br />
Co(NS')3 - - - - - - -<br />
Ni(NS')2 - - - - - 6 -<br />
Cu(NS')2. H2O 10 9 10 9 - - -<br />
Zn(NS')2 - - - - - - 6<br />
Cd(NS')2 - - - - - - 8<br />
Streptomyc<strong>in</strong><br />
(antimicrobial<br />
control) 25 15 17 20<br />
Nystat<strong>in</strong><br />
(antifungal control) 23 24 28<br />
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ISBN : 978 – 979 – 19201 – 0 – 0<br />
Methicill<strong>in</strong> resistant Staphylococcus (MRSA); Bacillus subtilis wild type (B29); S.typhimurium – Salmonella<br />
typhimurium; Pseudomonas aerug<strong>in</strong>osa (60690); Candida albicans (C.A); Aspergillus ochraceous (398);<br />
Saccharomyces cerivisiae (20341)<br />
a Diameter <strong>of</strong> 15 mm and above considered active; - <strong>in</strong>active<br />
Conclusion<br />
<strong>The</strong> biological activity results showed that the<br />
thiophene derivatives were not promis<strong>in</strong>g undergo<br />
aga<strong>in</strong>st the targeted pathogens/cell l<strong>in</strong>es. Small<br />
changes <strong>in</strong> the backbone <strong>of</strong> the structure <strong>of</strong> a ligand<br />
(with phenyl r<strong>in</strong>g) was unable to br<strong>in</strong>g about great<br />
changes <strong>in</strong> the potential bioactivity <strong>of</strong> the ligands or<br />
their complexes. Furthermore, the presence <strong>of</strong> the<br />
thiophene r<strong>in</strong>g <strong>in</strong> the compounds synthesized did not<br />
show any enhanced biological activity as compared<br />
to similar compounds with a furyl group. This was <strong>in</strong><br />
contrast to results found for acetylthiophene isomers<br />
(2-acetylthiophene and 3-acetylthiophene).<br />
Acknowledgements<br />
We thank the Department <strong>of</strong> Chemistry, Universiti<br />
Putra Malaysia for support and the provision <strong>of</strong><br />
laboratory facilities. Also to Cl<strong>in</strong>ical Genetics Unit,<br />
Department <strong>of</strong> Human Growth and Development,<br />
Faculty <strong>of</strong> Medic<strong>in</strong>e and Health Science and the<br />
Laboratory <strong>of</strong> Molecular and Cell Biology, Institute<br />
<strong>of</strong> BioSciences, Universiti Putra Malaysia for the<br />
Biological studies. This work has been carried out<br />
with the f<strong>in</strong>ancial support from M<strong>in</strong>istry <strong>of</strong> Science<br />
and Environment, Malaysia, under the Intensification<br />
<strong>of</strong> Research <strong>in</strong> Priority Area (IRPA) program (Grant<br />
no 09-02-04-0755-EA001)<br />
References<br />
[1] Das, M. and Liv<strong>in</strong>gstone, S. E. (1976). Metal<br />
Chelates <strong>of</strong> Dithiocarhazic Acid and Its Derivatives.<br />
IX. Metal Chelates <strong>of</strong> Ten New Schiff Bases derived<br />
from S-Methyldithiocarhazate. Inorganica Chimica<br />
Acta.19. 5-10.<br />
[2] Akbar Ali, M., Mirza, A. H., Nazimudd<strong>in</strong>, M.,<br />
Ahmed, R., Gahan, L. R. and Bernhardt, P. V. (2003)<br />
Synthesis and characterization <strong>of</strong> mono- and bisligand<br />
z<strong>in</strong>c(II) and cadmium(II) complexes <strong>of</strong> the di-<br />
2-pyridylketone Schiff base <strong>of</strong> S-benzyl<br />
dithiocarbazate (Hdpksbz) and the X-ray crystal<br />
structures <strong>of</strong> the [Zn(dpksbz)2] and<br />
[Cd(dpksbz)NCS]2 complexes. Polyhedron. 22 (11)<br />
1471-1479.<br />
[3] Akbar Ali, M., Mirza, A. H., Nazimudd<strong>in</strong>, M.,<br />
Rahman, H. and Butcher, R. J. (2001) Mono- and bis-<br />
chelated nickel(II) complexes <strong>of</strong> the di-2pyridylketone<br />
Schiff base <strong>of</strong> S-methyldithiocarbazate<br />
and the X-ray crystal structure <strong>of</strong> the bis[S-methyl-<br />
[beta]-N-(di-2-pyridyl)methylenedithiocarbazato]nickel(II)<br />
complex.<br />
Polyhedron. 20 (19) 2431-2437.<br />
[4] Akbar Ali, M., Mirza, A. H., Voo, C. W., Tan, A.<br />
L. and Bernhardt, P. V. (2003) <strong>The</strong> preparation <strong>of</strong><br />
z<strong>in</strong>c(II) and cadmium(II) complexes <strong>of</strong> the<br />
pentadentate N3S2 ligand formed from 2,6diacetylpyrid<strong>in</strong>e<br />
and S-benzyldithiocarbazate<br />
(H2SNNNS) and the X-ray crystal structure <strong>of</strong> the<br />
novel dimeric [Zn2(SNNNS)2] complex. Polyhedron.<br />
22 (27) 3433-3438<br />
[5] Ali, M.A., Mirza, A. H., Tan, A. L., Wei, L. K.<br />
and Bernhardt, P. V. (2004) <strong>The</strong> preparation and<br />
characterization <strong>of</strong> seven-coord<strong>in</strong>ate t<strong>in</strong>(IV)<br />
complexes <strong>of</strong> the 2,6-diacetylpyrid<strong>in</strong>e Schiff bases <strong>of</strong><br />
S-alkyl/aryl-dithiocarbazates and the X-ray crystal<br />
structure <strong>of</strong> the [Sn(dapsme)I2] complex<br />
(dapsme=doubly deprotonated form <strong>of</strong> the 2,6diacetylpyrid<strong>in</strong>e<br />
Schiff base <strong>of</strong> Smethyldithiocarbazate).<br />
Polyhedron. 23 (11) 2037-<br />
2043.<br />
[6] Tarafder, M. T. H., Khoo, T. J., Crouse, K. A.,<br />
Ali, A. M., Yam<strong>in</strong>, B. M. and Fun, H. K. (2002)<br />
Coord<strong>in</strong>ation chemistry and bioactivity <strong>of</strong> Ni 2+ , Cu 2+ ,<br />
Cd 2+ and Zn 2+ complexes conta<strong>in</strong><strong>in</strong>g bidentate Schiff<br />
bases derived from S-benzyldithiocarbazate and the<br />
X-ray crystal structure <strong>of</strong> bis[S-benzyl-[beta]-N-(5methyl-2-furylmethylene)dithiocarbazato]<br />
cadmium(II). Polyhedron. 21 (25-26) 2547-2554.<br />
[7] Tarafder, M.T.H., Chew, K. B., Crouse, K. A.,<br />
Ali, A. M., Yam<strong>in</strong>, B. M. and Fun, H. K. (2002)<br />
Synthesis and characterization <strong>of</strong> Cu(II), Ni(II) and<br />
Zn(II) metal complexes <strong>of</strong> bidentate NS isomeric<br />
Schiff bases derived from S-methyldi-thiocarbazate<br />
(SMDTC): bioactivity <strong>of</strong> the bidentate NS isomeric<br />
Schiff bases, some <strong>of</strong> their Cu(II), Ni(II) and Zn(II)<br />
complexes and the X-ray structure <strong>of</strong> the bis[Smethyl-[beta]-N-(2-furylmethyl)methylenedithiocarbazato]z<strong>in</strong>c(II)<br />
complex.<br />
Polyhedron. 21 (27-28) 2683-2690.<br />
[8] Tarafder, M. T. H., Khoo, T. J., Crouse, K. A.,<br />
Ali, A. M., Yam<strong>in</strong>, B. M. and Fun, H. K. (2002)<br />
Coord<strong>in</strong>ation chemistry and bioactivity <strong>of</strong> some<br />
metal complexes conta<strong>in</strong><strong>in</strong>g two isomeric bidentate<br />
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NS Schiff bases derived from Sbenzyldithiocarbazate<br />
and the X-ray crystal structures<br />
<strong>of</strong> S-benzyl-[beta]-N-(5-methyl-2-furylmethylene)<br />
dithiocarbazate and bis[S-benzyl-[beta]-N-(2furylmethylketone)dithiocarbazato]cadmium(II).<br />
Polyhedron. 21 (27-28) 2691-2698.<br />
[9] Chew, K. B., Tarafder, M. T. H., Crouse, K. A.,<br />
Ali, A. M., Yam<strong>in</strong>, B. M. and Fun, H. K. (2004)<br />
Synthesis, characterization and bio-activity <strong>of</strong> metal<br />
complexes <strong>of</strong> bidentate N-S isomeric Schiff bases<br />
derived from S-methyldithiocarbazate (SMDTC) and<br />
the X-ray structure <strong>of</strong> the bis[S-methyl-[beta]-N-(2furyl-methylketone)dithiocarbazato]cadmium<br />
(II)<br />
complex. Polyhedron. 23 (8) 1385-1392.<br />
[10] Tarafder, M. T. H., Kasbollah, A., Crouse, K.<br />
A., Ali, A. M., Yam<strong>in</strong>, B. M. and Fun, H. K. (2001)<br />
Synthesis and characterization <strong>of</strong> Zn(II) and Cd(II)<br />
complexes <strong>of</strong> S-benzyl-[beta]-N-(2pyridyl)methylenedithiocarbazate<br />
(HNNS):<br />
bioactivity <strong>of</strong> the HNNS Schiff base and its Zn(II),<br />
Cu(II) and Cd(II) complexes and the X-ray structure<br />
<strong>of</strong> the [Zn(NNS)2] complex. Polyhedron. 20 (18)<br />
2363-2370.<br />
[11] Mosmann, T. (1983) Rapid colorimetric assay<br />
for cellular growth and survival: Application to<br />
proliferation and cytotoxicity assays. Journal <strong>of</strong><br />
Immunological Methods. 65 (1-2) 55-63.<br />
[12] Bauer, A.W.,Kirny, M.D.K., Sherries, J.C., and<br />
Turck, M. (1996). Am. J. Cl<strong>in</strong>. Pathol. 45: 493.<br />
[13] Hufford, C.D., and Clark, A.M.(1988).<br />
Discovery and development <strong>in</strong> the new drug for<br />
systematic oppurtunitic <strong>in</strong>fections, studies <strong>in</strong> natural<br />
product chemistry. Elsevier 2: 421-452<br />
[14] S<strong>in</strong>gh, S., Bharti, N., Naqvi, F. and Azam, A.<br />
(2004) Synthesis, characterization and <strong>in</strong> vitro<br />
Antiamoebic Activity <strong>of</strong> 5-nitrothiophene-2carboxaldehyde<br />
thiosemicarbazones and their<br />
Palladium(II) and Ruthenium(II) Complexes.<br />
European Journal <strong>of</strong> Medic<strong>in</strong>al Chemistry. 39 (5)<br />
459-465.<br />
[15] Shailendra, Neelam Bharti, Fehmida Naqvi and<br />
Amir Azam (2003). Synthesis, Spectral Studies and<br />
Screen<strong>in</strong>g for Amoebicidal Activity <strong>of</strong> New<br />
Palladium(II) Complexes Derived from Thiophene-2carboxaldehyde<br />
Thiosemicarbazones, Bioorganic &<br />
Medic<strong>in</strong>al Chemistry Letters, 13: 689–692.<br />
[16] Shailendra, Bharti, N., Gonzalez Garza, M. T.,<br />
Cruz-Vega, D. E., Castro Garza, J., Saleem, K.,<br />
Naqvi, F. and Azam, A. (2001) Synthesis,<br />
characterisation and antiamoebic activity <strong>of</strong> new<br />
thiophene-2-carboxaldehyde thiosemicarbazone<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
derivatives and <strong>The</strong>ir cyclooctadiene Ru(II)<br />
complexes. Bioorganic & Medic<strong>in</strong>al Chemistry<br />
Letters. 11 (20) 2675-2678.<br />
[17] Chaviara, A. T., Cox, P. J., Repana, K. H.,<br />
Pantazaki, A. A., Papazisis, K. T., Kortsaris, A. H.,<br />
Kyriakidis, D. A., Nikolov, G. St. and Bolos, C.A.<br />
(2005) <strong>The</strong> unexpected formation <strong>of</strong> biologically<br />
active Cu(II) Schiff mono-base complexes with 2thiophene-carboxaldehyde<br />
and dipropylenetriam<strong>in</strong>e:<br />
crystal and molecular structure <strong>of</strong> CudptaSCl2.<br />
Journal <strong>of</strong> Inorganic Biochemistry. 99 (2) 467-476.<br />
[18] Mun-Hoe Eddy Chan (2005). Synthesis,<br />
Characterisation & Bioactivity <strong>of</strong> substituted<br />
Dithiocarbazate Schiff Bases <strong>of</strong> Acetylthiophenyl<br />
Isomer and <strong>The</strong>ir Metal Complexes, M. Sc. <strong>The</strong>sis,<br />
Universiti Putra Malaysia, Malaysia.<br />
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Introduction<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
Selectivity and Cation Exchange Capacity Determ<strong>in</strong>ation ff <strong>Zeolite</strong><br />
from Fly Ash<br />
Nungki Puspita Sari, Hamzah Fansuri, Lukman Atmaja<br />
Chemistry Department, Faculty <strong>of</strong> Mathematics and Natural Sciences<br />
Institut Teknologi Sepuluh November (<strong>ITS</strong>) Surabaya<br />
Keputih Sukolilo Surabaya, East Java, Indonesia<br />
Correspond<strong>in</strong>g Author: h.fansuri@chem.its.ac.id<br />
Abstract<br />
Cation exchange capacity <strong>of</strong> <strong>Zeolite</strong> A, synthesized from fly ash by us<strong>in</strong>g a two step process namely<br />
fusion and then followed by hydrothermal, was <strong>in</strong>vestigated by ammonium acetate and barium chloride<br />
methods. Ammonium acetate method is the common way to measure cation exchange capacity <strong>of</strong><br />
zeolites. However the Barium chloride was reported as hav<strong>in</strong>g an advantage than the ammonium acetate<br />
because the exchange process is not an equilibrium reaction s<strong>in</strong>ce the exchange product is a non water<br />
soluble salt. <strong>The</strong> experimental results give quite different exchange capacity. <strong>The</strong> Barium method found<br />
that the capacity is 1.15 meq/g while the ammonium method found 3.52 meq/g. <strong>The</strong> result disparity is<br />
due to the pore open<strong>in</strong>g <strong>of</strong> zeolite A which is not large enough to be accessed by large barium ions and<br />
therefore not all exchangeable cation can be exchanged by the barium ion. <strong>The</strong> selectivity, acquired<br />
from the ratio <strong>of</strong> selectivity coefficient <strong>of</strong> the cation, <strong>of</strong> s<strong>in</strong>gle component system follows the order Ca 2+<br />
> K + >NH 4 + > Mg 2+ . Meanwhile, <strong>in</strong> a multi-component exchanged cation is <strong>in</strong> the order <strong>of</strong> Ca 2+ > Mg 2+<br />
> NH4 + >K + . It was found that higher valence cations are more selective than the lower one.<br />
Keyword: cation exchange capacity, fly ash, selectivity, zeolite<br />
Fly ashes are ma<strong>in</strong>ly produced from coal<br />
combustion. <strong>The</strong>y conta<strong>in</strong>s silicates and alum<strong>in</strong>ates,<br />
which are the ma<strong>in</strong> components <strong>of</strong> zeolite. Many<br />
zeolites were successfully synthesized from fly ash<br />
such as zeolite X [1, 2], Na-P1 [3], zeolite A [1],<br />
zeolit K-H [4], Analcime, Chabazite, Cancr<strong>in</strong>ite,<br />
Gismod<strong>in</strong>e, and Gmel<strong>in</strong>ite [5].<br />
<strong>Zeolite</strong>s have capability to exchange their<br />
cation which is proportional to Al 3+ concentration <strong>in</strong><br />
their framework. Structure with lower Si/Al ratio has<br />
higher exchangeable cation. <strong>The</strong>ir framework stability<br />
<strong>in</strong>creases by the <strong>in</strong>crease <strong>of</strong> Si/Al ratio. <strong>Zeolite</strong> A is a<br />
synthetic zeolite that has high cation exchange<br />
capacity (CEC) due to its high Si/Al ratio. Cation<br />
exchange capacity is the most useful nature <strong>of</strong><br />
zeolites.<br />
García-Sosa and Solache-Ríos [6] reported<br />
that zeolite A with Si/Al ratio = 1 has theoretical and<br />
experimental CEC 5,3 and 4,06 meq/g, respectively.<br />
<strong>The</strong> authors determ<strong>in</strong>ed the CEC us<strong>in</strong>g ammonium<br />
acetate method. Lower CEC (3,5 meq/g) <strong>of</strong> zeolite A<br />
which was synthesized from fly ash was reported by<br />
Wang et al. [7].<br />
Several experiments have been reported <strong>in</strong><br />
relation to cation selectivity <strong>of</strong> zeolites. Langella et.al<br />
[8] found that NH4 + and Pb 2+ selectivities <strong>in</strong><br />
cl<strong>in</strong>optilolite are better than Cu 2+ , Zn 2+ and Cd 2+ . <strong>The</strong><br />
selectivity order is NH4 + > Pb 2+ > Na + > Cd 2+ > Cu 2+ ≈<br />
Zn 2+ . Whereas Inglezakis et.al [9] reported the cation<br />
selectivity <strong>of</strong> cl<strong>in</strong>optilolite at total concentration <strong>of</strong><br />
cation 0,01 N and acidity 2 <strong>in</strong> both s<strong>in</strong>gle- and<br />
multicomponent solution follow the order Pb 2+ ><br />
Fe 3+ > Cr 3+ ≥ Cu 2+ . On the other hand selectivity <strong>in</strong><br />
s<strong>in</strong>gle metal solutions where acidity is not adjusted<br />
follow the order <strong>of</strong> Pb 2+ >Cr 3+ >Fe 3+ ≈Cu 2+ . When the<br />
zeolite was analchime, the cation exchange selectivity<br />
follows the order Pb 2+ > Cu 2+ > Zn 2+ > Ni 2+ [10]. Thus,<br />
it was shown that different zeolites will have different<br />
cation exchange selectivity.<br />
This paper reports the experimental cation<br />
exchange capacity and cation selectivity toward Ca 2+ ,<br />
Mg 2+ , NH4 + , K + <strong>of</strong> the zeolites synthesized from fly<br />
ash.<br />
Materials And Methods<br />
Materials<br />
Chemicals that were used <strong>in</strong> this experimet are<br />
BaCl2.2H2O (Merck, pa), aqua DM, CH3COONH4<br />
(Merck, pa), KCl (Mall<strong>in</strong>crodt, pa), MgCl2.6H2O<br />
(pa), CaCl2.2H2O (pa), aquades, NaOH (Merck,pa),<br />
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NaAlO2 (Riedel-de Haën, Al2O3 50-56 %; Na2O 40-<br />
45%; Fe2O3 maksimum 0,05 %), tecnical ethanol.<br />
Methods<br />
<strong>The</strong> synthesis <strong>of</strong> <strong>Zeolite</strong> A<br />
<strong>The</strong> zeolite A used was syntesized from fly<br />
ash accord<strong>in</strong>g to a method which was reported by<br />
Sudarno [11]. Firstly, the fly ash was fused with<br />
NaOH at 2:3 mass ratio <strong>of</strong> fly ash to NaOH <strong>in</strong> a<br />
muffle furnace at 600 o C for 2 hours. <strong>The</strong>n, the fused<br />
mass was allowed to cool<strong>in</strong>g down to room<br />
temperature <strong>in</strong> a desiccator. When the mass reach<br />
room temperature, it was dissolved <strong>in</strong> 127.5 mL <strong>of</strong><br />
water and stirred for 12 hour. Un-dissolved solids<br />
were separated from the solution by filtration and the<br />
composition <strong>of</strong> the filtrate was adjusted so the molar<br />
ratios <strong>of</strong> SiO2/Al2O3, Na2O/SiO2, H2O/Na2O becomes<br />
1.64, 8.09 and 56.51, respectively. <strong>The</strong> adjusted<br />
solution then was crystallized <strong>in</strong> a hydrothermal<br />
reactor at 100 o C for 12 hours. <strong>The</strong> crystal products<br />
were filtered, washed with aqua DM until the pH <strong>of</strong><br />
the filtrate was 10 and then dried at 100 o C for 24<br />
hours. X-ray diffraction technique was used to<br />
characterize the product.<br />
A similar product <strong>of</strong> zeolite A, which was<br />
synthesized from TEOS (Tetra Ethyl Ortho Silicate)<br />
and NaAlO2, was also prepared as a reference.<br />
Cation Exchange Capacity (CEC) determ<strong>in</strong>ation<br />
<strong>The</strong> CEC <strong>of</strong> zeolites were determ<strong>in</strong>ed us<strong>in</strong>g<br />
Barium chloride and Ammonium acetate methods. In<br />
barium acholired method, half gram (0.50 g) <strong>of</strong><br />
zeolite sample were added <strong>in</strong>to a 5 mL barium<br />
chloride solution 0,5 N <strong>in</strong> a conical flask. <strong>The</strong> mixture<br />
was shaken for 24 hours. <strong>The</strong>n, the solution was<br />
sentrifuged at 1000 rpm for 15 m<strong>in</strong>utes to separate the<br />
supernatant from the zeolite. <strong>The</strong>n, 10 mL <strong>of</strong> barium<br />
chloride solution 1 N was added to the zeolite and<br />
shake for another 2 hours. <strong>The</strong> zeolite was separated<br />
and washed with 20 mL ethanol 96%. This procedure<br />
saturated the zeolite with Ba 2+ . <strong>The</strong> Ba 2+ saturated<br />
zeolite was then added <strong>in</strong>to 22,5 mL <strong>of</strong> ammonium<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
acetate 1 M and shaken for 24 hours. <strong>The</strong> supernatant<br />
was separated from the zeolite by centrifugation and<br />
then analyzed with ICP-AES [12] for Ba 2+ ion<br />
concentration. In the ammonium acetate procedure,<br />
the barium chloride was replaced by potassium<br />
chloride.<br />
<strong>The</strong> Cation Exchange Capacity (CEC) was<br />
determ<strong>in</strong>ed by calculat<strong>in</strong>g the number <strong>of</strong> equivalents<br />
<strong>of</strong> Ba 2+ or K + replaced by ammonium ion (NH4 + ).<br />
Cation Selectivity Determ<strong>in</strong>ation<br />
One and a half gram <strong>of</strong> zeolite was added to<br />
a conical flask conta<strong>in</strong><strong>in</strong>g 50 ml <strong>of</strong> s<strong>in</strong>gle and mixedmetal<br />
solutions at total concentration <strong>of</strong> 1 N and<br />
shook for 24 hours. <strong>The</strong> follow<strong>in</strong>g solutions were<br />
used <strong>in</strong> cation selectivity determ<strong>in</strong>ation:<br />
(a) Solutions <strong>of</strong> s<strong>in</strong>gle cation (KCl, CaCl2, MgCl2,<br />
NH4CH3COO) where the concentration <strong>of</strong> each<br />
cation was 1 N.<br />
(b) Four-component solution where the<br />
concentration <strong>of</strong> each cation was 0.25 N.<br />
Liquid samples were taken from the cont<strong>in</strong>uously<br />
shakes mixture at 1, 3, 6, 12, 24 hours where total<br />
volume <strong>of</strong> the samples were not exceed<strong>in</strong>g 4% <strong>of</strong> the<br />
total volume <strong>of</strong> <strong>in</strong>itial solution. <strong>The</strong> concentration <strong>of</strong><br />
metal cations <strong>in</strong> the liquid samples was measured<br />
with ICP AES and ammonium was determ<strong>in</strong>ed<br />
spectrophotometrically us<strong>in</strong>g Nessler reagent.<br />
Result and Discussion<br />
Cation Exchange Capacity (CEC)<br />
CEC is a calculated value that is an estimate<br />
<strong>of</strong> materials ability to attract, reta<strong>in</strong>, and exchange<br />
cation elements. In this experiment, CEC <strong>of</strong> zeolite<br />
products were determ<strong>in</strong>ed by Barium Chloride<br />
method [12]. A few modifications were used <strong>in</strong> this<br />
method. Barium that enter framework were<br />
exchanged with ammonium. Ammonium acetate<br />
method is used for comparator <strong>of</strong> barium chloride<br />
method. <strong>The</strong> CEC was calculated by Equation (3.1).<br />
Table 1 shows the CEC values <strong>of</strong> zeolite A.<br />
− 1 V ( L)<br />
100g<br />
CEC(<br />
meq / 100g)<br />
= ( mgL cation)<br />
× ×<br />
(3.1)<br />
MECation zeolite(<br />
g)<br />
Table 1 Cation Exchange Capacity <strong>of</strong> <strong>Zeolite</strong> from Fly Ash and TEOS<br />
Sample <strong>Zeolite</strong><br />
CEC<br />
(meq/ 100 g) a<br />
CEC<br />
(meq/ 100 g) b<br />
CEC calculated<br />
(meq/100 g) c<br />
<strong>Zeolite</strong> from TEOS 189,72 320,94<br />
530<br />
Zeolit from fly ash 115,83 352,27<br />
a. barium chlorida method, b. ammonium acetate method, c. García-Sosa and Solache-Ríos (2001)<br />
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Table 1 shows that CEC <strong>of</strong> zeolite from<br />
TEOS and fly ash us<strong>in</strong>g ammonium acetate method is<br />
higher than us<strong>in</strong>g barium chloride method. It<br />
happened because particle size <strong>of</strong> potassium ion is<br />
smaller (r(K + ) = 133 pm) than barium (r(Ba 2+ ) = 143<br />
pm) so the potassium ion can enter the cation site <strong>in</strong><br />
the pore the zeolite easier than the barium ion.<br />
<strong>The</strong> Table also shows that the CEC <strong>of</strong> zeolite<br />
from TEOS is higher than those from fly ash while it<br />
is lower for the zeolites synthesized from fly ash.<br />
<strong>Zeolite</strong> from TEOS conta<strong>in</strong>s higher purity zeolite A<br />
Figure 1 <strong>The</strong> X-ray diffractograms <strong>of</strong> zeolite A from: a) fly ash and b) TEOS<br />
<strong>The</strong> ma<strong>in</strong> impurities <strong>in</strong> the zeolite A<br />
synthesized from fly ash are amorphous phases.<br />
<strong>The</strong> phases are clearly shown as the basel<strong>in</strong>e <strong>of</strong><br />
zeolite A from fly ash is more curvature than those<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
while those from fly ash has lower zeolite A purity<br />
where the impurity might be other zeolites with<br />
smaller apertures to the site <strong>of</strong> exchangeable cation.<br />
Thus, only smaller cations have higher probability to<br />
enter the sites and replace the cations. <strong>The</strong> difference<br />
<strong>in</strong> zeolite A purity can be seen from the diffractogram<br />
<strong>of</strong> the zeolites <strong>in</strong> Figure 1.<br />
(a)<br />
(b)<br />
JCPDS-ICDD<br />
No PDF 39-0222<br />
from TEOS. <strong>The</strong>se phases may conta<strong>in</strong> very f<strong>in</strong>e<br />
crystal <strong>of</strong> other types <strong>of</strong> zeolites which can<br />
exchange their cations and thus added to the total<br />
exchangeable cations <strong>in</strong> the zeolite product.<br />
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<strong>The</strong> difference <strong>in</strong> the CEC might also been<br />
caused by the use <strong>of</strong> TEOS as a source material <strong>in</strong><br />
the zeolite synthesis. <strong>The</strong> hydrolysis <strong>of</strong> TEOS<br />
which was occurred dur<strong>in</strong>g the hydrothermal<br />
process produced ethanol that may be trapped <strong>in</strong> the<br />
cation exchange sites so that exchange cations<br />
cannot enter the site.<br />
Table 2 CEC Comparison us<strong>in</strong>g Ammonium Acetate and BaCl2 Method [12-14]<br />
KOH<br />
Reaction Condition<br />
Initial<br />
Hydrothermal<br />
time<br />
Initial<br />
Hydrothermal<br />
temperature<br />
CEC (a)<br />
(mek/100 g)<br />
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<strong>The</strong> same results were also found when the<br />
two CEC determ<strong>in</strong>ation methods were used for<br />
other zeolites from fly ash, prepared by Hidayati<br />
[13], Nafiah [14] and Muasyaroh [15]. All zeolite<br />
synthesized from fly ash shows higher CEC value<br />
when determ<strong>in</strong>ed us<strong>in</strong>g ammonium acetate than<br />
us<strong>in</strong>g barium chloride method as shown <strong>in</strong> Table 2.<br />
CEC (b)<br />
(mek/100 g)<br />
3 M 1 Hours 180C 325,81 6,80 K-F<br />
M<strong>in</strong>eral Phases<br />
3 M 3,5 Hours 180C 309,11 9,40 M,Q, K-F,K-P<br />
3 M 5 Hours 180C 397,80 7,20 K-F<br />
3 M 3,5 Hours 100C 230,39 6,04 M,Q, K-F, K-G,K-P<br />
3 M 3,5 Hours 120C 250,94 5,52 M,Q, K-F, K-G,K-P<br />
1 M 3,5 Hours 180C 261,00 6,95 K-M, M<br />
5 M 3,5 Hours 180C 134,10 4,03 K-D<br />
(a) Ammonium acetate method; (b) BaCl2 method<br />
M: Mullite; Q: Quartz; K-F: zeolite K-F (LTF) ;K-P: K-Phillipsite; K-G: K- Chabasite; K-M: zeolite K-M; K-D:<br />
Kaliophilite<br />
Cation Selectivity<br />
Cation exchange reaction <strong>in</strong> zeolites can<br />
be written as Equation 3.2. Initially the sodium ions<br />
are <strong>in</strong> the cation site <strong>of</strong> the zeolites. When they are<br />
replaced by the exchange cation <strong>in</strong> a solution, the<br />
sodium ion will be exiled from the zeolite and<br />
available <strong>in</strong> the exchange solution. <strong>The</strong>refore, the<br />
equilibrium state <strong>of</strong> the exchange reaction which<br />
shows the degree <strong>of</strong> exchange can be studied from<br />
the concentration <strong>of</strong> sodium ion <strong>in</strong> the exchange<br />
solution at the equilibrium state. Equation 3.3 and<br />
3.4 are examples <strong>of</strong> the reaction us<strong>in</strong>g cations with<br />
different oxidation states. <strong>The</strong>y show that cation<br />
with higher oxidation number can exchange more<br />
sodium ion than the lower ones.<br />
(nNa)-<strong>Zeolite</strong> + A n+ = A-zeolite + nNa + ................................................... (3.2)<br />
Na-zeolite + KCl = K-zeolite + NaCl ................................................. (3.3)<br />
(2Na)-zeolite + CaCl2 = Ca-<strong>Zeolite</strong> + 2NaCl ............................................. (3.4)<br />
Figure 2 shows sodium extracted by Mg 2+ ,<br />
Ca 2+ , K + , and NH4 + at the equilibrium state. <strong>The</strong><br />
extraction depends on the selectivity <strong>of</strong> the<br />
exchange reaction toward the <strong>in</strong>com<strong>in</strong>g cations and<br />
hence it means that the exchange selectivity follows<br />
the order Mg 2+ >NH4 + >K + ≈Ca 2+ .<br />
Interest<strong>in</strong>g result is shown by Mg 2+<br />
because the cation theoretically has higher<br />
capability to exchange the sodium ion than NH4 +<br />
and K + s<strong>in</strong>ce it has higher oxidation number. By<br />
virtue <strong>of</strong> the valence, magnesium should be capable<br />
to exchange with sodium <strong>in</strong> the same manner with<br />
calcium. Hence it is concluded that it may be<br />
precipitated dur<strong>in</strong>g the exchange reaction s<strong>in</strong>ce the<br />
pH <strong>of</strong> the zeolite is high. As aforementioned, the<br />
zeolite was washed until the pH was 10.<br />
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Sodium extracted (meq/L)<br />
180<br />
170<br />
160<br />
150<br />
140<br />
130<br />
0 5 10 15 20 25<br />
Time (hours)<br />
K +<br />
Ca 2+<br />
+<br />
NH4 Mg 2+<br />
Figure 2 Sodium extracted <strong>in</strong> s<strong>in</strong>gle component<br />
system<br />
Under alkali condition, magnesium<br />
precipitates to form Mg(OH)2. In comparison to<br />
calcium, the Mg(OH2) has smaller Ksp (7,1× 10 -12 )<br />
than Ca(OH)2 (Ksp= 6,5× 10 -6 ). <strong>The</strong>refore,<br />
although the condition <strong>of</strong> exchange is the same,<br />
Mg 2+ precipitates easier than Ca 2+ .<br />
Numerical value <strong>of</strong> cation selectivity dan<br />
be calculated us<strong>in</strong>g Equation 3.5. Table 3 shows the<br />
calculated selectivity based on experimental<br />
exchange data.<br />
[ ] [ ]<br />
A<br />
Z A ZC<br />
RC A<br />
K C / A = Z Z<br />
C RA<br />
(3.5)<br />
[ ] [ ] C<br />
Table 3 Selectivity coefficient <strong>in</strong> s<strong>in</strong>gle component<br />
system<br />
KK/Na KMg/Na KNH4/Na KCa/Na<br />
0.77 0.30 0.55 15.68<br />
<strong>The</strong> cation exchange raction <strong>in</strong> multicomponent<br />
system gives better <strong>in</strong>sight <strong>in</strong>to the real<br />
cation selectivity where each cation compete with<br />
others <strong>in</strong> the same system. As <strong>in</strong> a s<strong>in</strong>gle<br />
component system, the selectivity <strong>in</strong> multicomponent<br />
system was <strong>in</strong>vestigated based on the<br />
amount <strong>of</strong> extracted sodium from the zeolite as<br />
shown <strong>in</strong> Figure 3.3. <strong>The</strong> Figure shows that the<br />
equilibrium occurs at 3 hours<br />
Table 4 shows the selectivity coefficients<br />
<strong>of</strong> all cations used <strong>in</strong> this experiment. <strong>The</strong><br />
selectivity follows the order Ca 2+ > Mg 2+ ><br />
NH4 + >K + . Hence the order follows the rule that the<br />
ion exchange prefer higher valence cation.<br />
<strong>The</strong>refore, calcium and magnesium are more<br />
selective than ammonium and potassium as<br />
mentioned by Helferich [16].<br />
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Table 4 Selectivity Coefficient <strong>in</strong> multi-component<br />
system<br />
Sodium extracted (meq/L)<br />
210<br />
200<br />
190<br />
180<br />
170<br />
KK/Na KMg/Na KNH4/Na KCa/Na<br />
1.38 3.42 3.04 8.61<br />
0 5 10 15 20 25<br />
waktu (jam)<br />
Figure 3 Sodium extracted on multicomponent<br />
system<br />
Conclusions<br />
1. <strong>The</strong> CEC <strong>of</strong> zeolite from fly ash is 115,83<br />
meq/100g us<strong>in</strong>g barium chloride method and<br />
352,27 meq/100g us<strong>in</strong>g ammonium acetate<br />
method. <strong>The</strong> difference is due to different <strong>in</strong><br />
cation size <strong>of</strong> B 2+ <strong>in</strong> barium method and K +<br />
used <strong>in</strong> ammonium acetate method.<br />
2. Cation selectivity <strong>in</strong> s<strong>in</strong>gle component system is<br />
follow<strong>in</strong>g the order Ca 2+ >K + > Mg 2+ >NH4 + .<br />
Magnesium is the lowest because the zeolite is<br />
alkal<strong>in</strong>e that cause the formation <strong>of</strong><br />
magnesium hydroxide precipitate.<br />
3. Cation selectivity <strong>in</strong> multi-component system is<br />
follow<strong>in</strong>g the order Ca 2+ > Mg 2+ >K + > NH4 + .<br />
Cations with higher oxidation state have higher<br />
selectivity than the lower ones.<br />
Acknowledgment<br />
<strong>The</strong> authors acknowledge <strong>The</strong> M<strong>in</strong>istry <strong>of</strong><br />
Research and Technology for research grant under<br />
the scheme <strong>of</strong> Insentif Riset Terapan <strong>in</strong> 2007.<br />
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References<br />
1. Ojha, K., Pradhan, N.C. and Samanta, A.N.<br />
(2004), ”<strong>Zeolite</strong> from fly ash: synthesis<br />
and characterization”, Mater Sci B, Vol<br />
27, No 6, p. 555–64.<br />
2. Chang, H.L. and Shih, W.H. (2000), “Synthesis<br />
<strong>of</strong> <strong>Zeolite</strong>s A and X from Fly Ashes and<br />
<strong>The</strong>ir Ion-Exchange Behavior with Cobalt<br />
Ions”, Ind. Eng. Chem. Res., Vol 39, p.<br />
4185-4191<br />
3. Woolard, C.D., Petrus, K. and van der Horst, M.<br />
(2000), “<strong>The</strong> use <strong>of</strong> a modified fly ash as<br />
an adsorbent for lead”, Water SA , Vol 26<br />
(4), p. 531–536.<br />
4. Mimura, H.K, Yokota, K., Akiba, Y. and<br />
Onodera, Y. (2001), “Alkali hydrothermal<br />
synthesis <strong>of</strong> zeolites from coal fly ash and<br />
their uptake properties <strong>of</strong> cesium ion”, J<br />
Nucl Sci Technol; Vol 38(9), p. 766–772.<br />
5. Elliot, A.D and Zhang, D.K. (2005), “Controlled<br />
Release <strong>Zeolite</strong> Fertilizers: A Value Added<br />
Product Produced from Fly Ash”,<br />
www.flyash.<strong>in</strong>fo/2005, Perth.<br />
6. García-Sosa. I and Solache-Ríos. M. (2001),<br />
“Cation-exchange capacities <strong>of</strong> zeolites A,<br />
X, Y, ZSM-5 and Mexican erionite<br />
compared with the retention <strong>of</strong> cobalt and<br />
cadmium”, Journal <strong>of</strong> Radioanalytical and<br />
Nuclear Chemistry, Vol. 250, No. 1, p.<br />
205–206.<br />
7. Wang, C.F., Li, J.S., Wang, L.J. and Sun, X.Y.<br />
(2008), "Influences <strong>of</strong> NaOH<br />
Concentrations on Synthesis <strong>of</strong> Pure-Form<br />
<strong>Zeolite</strong> A from Fly Ash us<strong>in</strong>g Two-Stage<br />
Method", Journal <strong>of</strong> Hazardous Materials,<br />
Vol. 155, p. 58-64.<br />
8. Langella, A., Pans<strong>in</strong>i, M., Cappelletti, P., de<br />
Gennaro, B. and de Gennaro, .M. (2000),<br />
”NH4 + , Cu 2+ , Zn 2+ , Cd 2+ and Pb 2+ exchange<br />
for Na + <strong>in</strong> sedimentary cl<strong>in</strong>optilolite, North<br />
Sard<strong>in</strong>ia, Italy”, Microporous and<br />
Mesoporous Materials, Vol. 37, p. 337–<br />
343.<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
9. Inglezakis, V.J, Loizidou, M.D. and<br />
Grigoropoulou, H.P. (2003), “Ion<br />
exchange <strong>of</strong> Pb 2+ , Cu 2+ , Fe 3+ , and Cr 3+ on<br />
natural cl<strong>in</strong>optilolite: selectivity<br />
determ<strong>in</strong>ation and <strong>in</strong>fluence <strong>of</strong> acidity on<br />
metal uptake”, Journal <strong>of</strong> Colloid and<br />
Interface science, Vol. 261, p. 49-54.<br />
10. Tangkawanit, S., Rangsriwatananon, K. and<br />
Dyer, A. (2005), ”Ion exchange <strong>of</strong> Cu 2+ ,<br />
Ni 2+ , Pb 2+ and Zn 2+ <strong>in</strong> analcime (ANA)<br />
synthesized from Thai perlite”,<br />
Microporous and Mesoporous Materials,<br />
Vol. 79, p. 171 –175.<br />
11. Sudarno (2008), Pengaruh Komposisi NaOH<br />
Pada Konversi Abu Layang Batubara<br />
Paiton Menjadi Zeolit A, Skripsi Sarjana<br />
Kimia, <strong>ITS</strong>, Surabaya.<br />
12. Gillman, G.P. (1979), “A Proposed Method for<br />
the Measurement <strong>of</strong> Exchange Properties<br />
<strong>of</strong> Highly Weathered Soils”, Aust. J. Soil<br />
Res., Vol. 17, p. 129-139.<br />
13. Hidayati, R.E, (2008), S<strong>in</strong>tesis zeolit dari abu<br />
layang batubara: kajian pengaruh waktu<br />
hidrotermal awal terhadap pembentukan<br />
zeolit, Tesis Magister Kimia, <strong>ITS</strong>,<br />
Surabaya.<br />
14. Nafiah, C. (2008), Pengaruh Komposisi KOH<br />
pada S<strong>in</strong>tesis Zeollit dari Abu Layang<br />
Batubara, Tesis Magister Kimia, <strong>ITS</strong>,<br />
Surabaya.<br />
15. Muasyaroh, D. (2008), Pengaruh Suhu<br />
Hidrotermal Awal terhadap Pembentukan<br />
Zeolit dari abu Layang Batubara, Tesis<br />
Magister Kimia, <strong>ITS</strong>, Surabaya.<br />
16. Helferich, F. (1962), Ion Exchange, McGraw-<br />
Hill Book Company, Inc., New York.<br />
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January 24, 2009<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
Relationship Pattern Between SiO2/Na2O Ratio<br />
and Microstructure <strong>of</strong> Fly Ash Based Geopolymer<br />
Mochamad Zakki Fahmi, Lukman Atmaja*, Hamzah Fansuri<br />
MasterDegree <strong>Study</strong>Program, Chemistry Departemant, Faculty <strong>of</strong> Mathematics and Natural Sciences Sepuluh<br />
Nopember Institute <strong>of</strong> Technology Surabaya, Sukolilo – Surabaya 60111<br />
* Correspond<strong>in</strong>g author<br />
Email address : lukman.at@gmail.com<br />
Introduction<br />
Abstract<br />
Convert<strong>in</strong>g fly ash to geopolymers is one <strong>of</strong> the most important scheme to reduce its dengerous effect to<br />
environment. <strong>The</strong> <strong>in</strong>itial molar contents <strong>of</strong> SiO2, Na 2O and Al 2O 3 <strong>of</strong> geopolymer systems gave some<br />
<strong>in</strong>fluence to geopolymer matrices. This research studied that the Na 2O gave effect to physical properties<br />
<strong>of</strong> Cilacap and Asam-asam fly ash-based geopolymers, which <strong>in</strong>crease SiO2/Na 2O ratio made positive<br />
effect to compressive strength and caused the microstructure <strong>of</strong> geopolymers more compact and<br />
homogen. Although NaOH (ma<strong>in</strong> source for variation SiO2/Na 2O ratio <strong>in</strong> this research) is needed for<br />
disolve fly ash particles, high content <strong>of</strong> sodium cation can discont<strong>in</strong>u geopolymersation process. <strong>The</strong><br />
effect <strong>of</strong> sodium cation has been <strong>in</strong>vestigated by quantiative analysis FTIR as well as their<br />
microstructure by SEM<br />
Key word : fly ash, geopolymer, microstructur, SiO2/Na 2O ratio<br />
Geopolymers , a k<strong>in</strong>d <strong>of</strong> <strong>in</strong>organic<br />
polymer, are alumnosilicate materials which exhibit<br />
excellent physical and chemical properties. S<strong>in</strong>ce<br />
1979, when davidovits first <strong>in</strong>troduced the term<br />
“geopolymers” to designate a new class <strong>of</strong> three<br />
dimensional alum<strong>in</strong>o-silicate materials (Davidovits,<br />
1979), the <strong>in</strong>terest toward the implementation <strong>of</strong><br />
new technologies for manufacture <strong>of</strong> great<br />
potentialities geopolymers based products has<br />
steadily grown. Geopolymers also exihibit a diverse<br />
range <strong>of</strong> potential applications, <strong>in</strong>clud<strong>in</strong>g precast<br />
structures and non-structural elements, concrete<br />
pavements and products, conta<strong>in</strong>ment and<br />
immobilisation <strong>of</strong> toxic, hazardous and radioactive<br />
wastes, advanced structural tool<strong>in</strong>g and refractory<br />
ceramics, and fire resistant composites used <strong>in</strong><br />
build<strong>in</strong>gs, aeroplanes, shipbuild<strong>in</strong>g, race cars and<br />
nuclear power <strong>in</strong>dustry (Komnitsas and Zaharaki,<br />
2007).<br />
<strong>The</strong> synthesis <strong>of</strong> geopolymers takes place<br />
by polycondensation and can start from a variety <strong>of</strong><br />
raw materials. Davidovits (1994, 1995), Schmücker<br />
and Mackenzie (2005), Xu et al. (2001,2002), Van<br />
Jaarsveld and van Deventer (1999,2003) and<br />
Duxson et al. (2005) use metakaol<strong>in</strong>ite to obta<strong>in</strong><br />
geopolymers by reaction with alkal<strong>in</strong>e (Na or K)<br />
solution. Meanwhile, Swanepoel and Strydom<br />
(2002), Fernández-Jiménez and Palomo<br />
(2003,2005), And<strong>in</strong>i et al.(2007), Álvarez-ayuso et<br />
al (2007) and Criado (2007) have proven that<br />
geopolymers could be obta<strong>in</strong>ed start<strong>in</strong>g material<br />
from many raw alum<strong>in</strong>o-silicates, <strong>in</strong>clud<strong>in</strong>g coal fly<br />
ash as start<strong>in</strong>g material. Also <strong>in</strong> this case the<br />
polycondensation takes place by reaction with<br />
alkal<strong>in</strong>e solution.<br />
In material contruction, fly ash based<br />
geopolymers is prefered over Portland cement<br />
because can reduce the emission <strong>of</strong> greenhouse<br />
gases <strong>in</strong>to the atmosphere (essentially CO2 and NOx;<br />
the manufacture <strong>of</strong> one tonne <strong>of</strong> cement generates<br />
approximately one tonne <strong>of</strong> CO2) (Criado, 2007).<br />
Beside that, Rangan et al. (2005) was estimated that<br />
production <strong>of</strong> fly ash based geopolymer concrete<br />
may be 10-30% cheaper than that <strong>of</strong> Portland<br />
cement concrete.<br />
Fly ash based geopolymers products and its<br />
process depend on many aspects, the SiO2/Al2O3,<br />
SiO2/Na2O and H2O/ Na2O ratio was commonly<br />
chemical aspects to make geopolymers materials<br />
with excellent physical and chemical properties.<br />
Álvarez-ayuso (2007), Alfiyah (2008), Muslihah<br />
(2008) and Mulyanto (2008) expla<strong>in</strong> that the<br />
SiO2/Na2O ratio <strong>in</strong> alkal<strong>in</strong>e solution affects the<br />
degree <strong>of</strong> polymerisation <strong>of</strong> the dissolved species.<br />
<strong>The</strong> <strong>in</strong>crease <strong>of</strong> NaOH conta<strong>in</strong> lead to <strong>in</strong>creas<strong>in</strong>g the<br />
dissolution <strong>of</strong> alum<strong>in</strong>o-silicate materials and,<br />
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consequently, geopolymers product will have<br />
excellent mechanical strength. Fernández-Jiménez<br />
and Palomo (2005), Lodeiro dkk.(2006) and De<br />
Silva dkk.(2007) have shown that <strong>in</strong>creas<strong>in</strong>g<br />
SiO2/Na2O ratio affects the production <strong>of</strong><br />
geopolimer because it <strong>in</strong>creases porosity and<br />
heterogenity.<br />
<strong>The</strong> SiO2/Al2O3, SiO2/Na2O and H2O/<br />
Na2O ratio and other chemical aspects can also<br />
<strong>in</strong>fluence other physical properties, such as<br />
microstructure and compressive strength. <strong>The</strong><br />
present paper is studied the microstructures <strong>of</strong> fly<br />
ash based geopolymers derived from the activation<br />
<strong>of</strong> fly ash by concentrated alkal<strong>in</strong>e solution (made<br />
from mixed sodium hydroxide and sodium silicate).<br />
Variation effect <strong>of</strong> SiO2/Na2O ratio is expected to<br />
show different geopolymer morphology and could<br />
be related to its compressive strength.<br />
Materials and Methods<br />
Material<br />
Class C (accord<strong>in</strong>g to ASTM C 618-03) fly<br />
ash from the Cilacap steam power plant and class F<br />
Table 1.Chemical analysis <strong>of</strong> the orig<strong>in</strong>al fly ash <strong>in</strong> precentage<br />
Cilacap<br />
fly ash<br />
(%)<br />
Asamasam<br />
fly ash<br />
(%)<br />
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fly ash from the Asam-asam steam power plant <strong>in</strong><br />
Indonesia were used <strong>in</strong> the present study. <strong>The</strong> ashs<br />
chemical composition are given <strong>in</strong> table 1.<br />
<strong>The</strong> ash activated with a series <strong>of</strong> alkal<strong>in</strong>e<br />
solution that consist <strong>of</strong> 98% NaOH pellet supplied<br />
by Merck and sodium silicate us<strong>in</strong>g follow<strong>in</strong>g<br />
composition : 37.99% Na2O, 19.16% SiO2 and<br />
28.07% H2O. H2O that use <strong>in</strong> the present study was<br />
destilated water. Composition <strong>of</strong> the systems studied<br />
is shown <strong>in</strong> table 2. Sodium hidroxsida content <strong>in</strong><br />
the solution was varied to have different SiO2/Na2O<br />
ratio.<br />
Method<br />
<strong>The</strong> properties <strong>of</strong> geopolymer matrices<br />
normally depend on the consistency <strong>of</strong> geopolymer<br />
materials and the consistency itself is <strong>in</strong>fluenced by<br />
the amount <strong>of</strong> enhanced water. <strong>The</strong>refore, to make<br />
consistency factor can be disregarded, all<br />
geopolymer reactant should have similar<br />
consistency. In this study, method for consistency<br />
test was adopted from C<strong>in</strong>daprasirt (2006). With<br />
same concistency, Solid/Liquid ratio is constant for<br />
whole geopolymer reactant.<br />
SiO2 Al2O3 CaO Fe2O3 K2O MgO Na2O P2O5 SO3 TiO2 MnO BaO SrO LOI Total<br />
31.5 12.4 21.4 22.5 0.75 7.87 0.27 0.12 1.06 0.76 0.27 0.24 0.09 0.49 99.72<br />
43.7 21 4.85 22.5 0.88 2.55 0.44 0.07 0.58 0.95 0.44 0.21 0.06 1.66 99.89<br />
LOI = loss on ignition<br />
Table 1.Composition <strong>of</strong> geopolymer systems were studied<br />
Sample * Fly ash<br />
(g)<br />
Na2SiO3<br />
(g)<br />
NaOH(g) H2O (g)<br />
As 1 40,38 10 20,96 10,37<br />
As 1,5 40,38 10 12,26 9,13<br />
As 2 40,38 10 7,92 8,46<br />
As 2,5 40,38 10 5,31 8,13<br />
As 3 40,38 10 3,57 7,88<br />
Ci 1 35,39 10 12,42 9,38<br />
Ci 1,5 35,39 10 6,60 8,38<br />
Ci 2 35,39 10 3,40 7,97<br />
Ci 2,5 35,39 10 1,95 7,64<br />
Ci 3 35,39 10 0,70 7,47<br />
*<br />
As refers to Asam-asam and Ci refers to Cilacap<br />
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<strong>The</strong> water content <strong>of</strong> geopolymers system<br />
is the amount <strong>of</strong> water added to the mixture <strong>of</strong> fly<br />
ash, NaOH and Na2SiO3, so that, the paste has a<br />
flow rate <strong>of</strong> 33 seconds when the paste was<br />
<strong>in</strong>cl<strong>in</strong>ated at 6,13°.<br />
<strong>The</strong> pastes were made by mix<strong>in</strong>g the fly<br />
ash with alkal<strong>in</strong>e solution, then shaped <strong>in</strong> cyl<strong>in</strong>drical<br />
conta<strong>in</strong>er (1.5 cm and 3 cm diameter and long,<br />
respectively) and cured <strong>in</strong> an oven at 60°C for 24<br />
hours. Geopolymer pellets were then kept <strong>in</strong> room<br />
temperature for different cur<strong>in</strong>g times (7, 14, 21 and<br />
28). Mechanical test us<strong>in</strong>g universal test<strong>in</strong>g mach<strong>in</strong>e<br />
and morphology analysis us<strong>in</strong>g scann<strong>in</strong>g electron<br />
microscopy (SEM), which conducted with energy<br />
dispersive X-ray (EDX), were conducted to pellets<br />
geopolymer <strong>in</strong> each cur<strong>in</strong>g time. <strong>The</strong> highest and the<br />
lowest compressive strength <strong>of</strong> pellets from Cilacap<br />
(Ci) and Asam-asam (As) were analyzed with<br />
fourier transform <strong>in</strong>frared (FTIR) for<br />
geopolymerisation paste study<br />
Results and Discussion<br />
Compressive Strength Analysis<br />
Compressive strength analysis was carried<br />
out to <strong>in</strong>vestigation <strong>in</strong> which composition system<br />
that hav<strong>in</strong>g excellent performaces. Compressive<br />
strength results <strong>of</strong> vary<strong>in</strong>g geopolymer pellets were<br />
shown <strong>in</strong> Fig.1 and Fig.2 for Cilacap and Asamasam<br />
geopolymers, respectively.<br />
Compressive strength(MPa)<br />
90<br />
80<br />
70<br />
60<br />
50<br />
40<br />
30<br />
20<br />
10<br />
7 day<br />
14 day<br />
21 day<br />
28 day<br />
0<br />
0.5 1.0 1.5 2.0 2.5 3.0<br />
Rasio SiO 2 /Na 2 O<br />
Figure. 1. Compressive strength result for Cilacap<br />
geopolymers<br />
Both Cilacap and Asam-asam geoplymers<br />
show that the compressive strengths result <strong>in</strong>crease<br />
Compressive strength (MPa)<br />
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with the <strong>in</strong>crease <strong>of</strong> cur<strong>in</strong>g times, facts, this is<br />
<strong>in</strong>dicated that geopolymerisation process still<br />
happens dur<strong>in</strong>g cur<strong>in</strong>g time and gives positive effect<br />
to the compressive strengths.<br />
Fig. 1. show that the <strong>in</strong>crease on<br />
SiO2/Na2O ratio for Cilacap geopolymers will<br />
<strong>in</strong>crease its comperssive strength and reach a max at<br />
SiO2/Na2O ratio = 3, ie. 81,53 MPa. Fig. 2 was<br />
Shown that the <strong>in</strong>crease on SiO2/Na2O ratio not<br />
always <strong>in</strong>creace the compressive strength. In Fig 2.,<br />
the highest compressive strength is owned by<br />
geopolymers with SiO2/Na2O ratio about 2,5 (40.48<br />
MPa). Panias et al.(2006) expla<strong>in</strong>ed that the<br />
<strong>in</strong>creased sodium hidroxide (NaOH) concentration<br />
<strong>of</strong> the aqueous phase <strong>of</strong> geopolymeric system cause<br />
positive, as well as negative effects on the<br />
mechanical properties <strong>of</strong> the geopolymeric<br />
materials. In low concentration, NaOH is used to<br />
dissolve Si and Al species from fly ash particles that<br />
produce component for geopolymerisation process.<br />
Whereas <strong>in</strong> high concentration, sodium cation,<br />
which are normally presented at high concentrations<br />
<strong>in</strong> the geopolymeric systems, are specifically<br />
adsorbed ions on the surface <strong>of</strong> fly ash particles<br />
chang<strong>in</strong>g the surface speciation (silanol and<br />
alum<strong>in</strong>ol). <strong>The</strong> sodium cation adsorption make<br />
chemical bond<strong>in</strong>g between the <strong>in</strong>soluble solid<br />
particle and the geopolymeric framework takes<br />
place <strong>in</strong> the f<strong>in</strong>al stage <strong>of</strong> geopolymeric process.<br />
Thus, the resulted geopolymeric materials have low<br />
low mechanical strength.<br />
40<br />
35<br />
30<br />
25<br />
20<br />
15<br />
10<br />
5<br />
7 day<br />
14 day<br />
21 day<br />
28 day<br />
0<br />
0.5 1.0 1.5 2.0 2.5 3.0<br />
Rasio SiO 2 /Na 2 O<br />
Fig. 2. Compressive strength result for Asamasam<br />
geopolymers<br />
Compar<strong>in</strong>g the compressive strengths<br />
between Cilacap and Asam-asam geopolymers, it<br />
can be seen thatt compressive strength from Cilacap<br />
geopolymers are normally higher than Asam-asam<br />
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geopolymers. This fact is <strong>in</strong> l<strong>in</strong>e with previous<br />
reportthat the CaO content <strong>of</strong> fly ash can give<br />
positive effect to geopolymer products, cause Ca +<br />
cation will form amorphously structured Ca-Al-Si<br />
gel <strong>in</strong> geopolymeric process (Komnitsas and<br />
Zaharaki, 2007).<br />
<strong>The</strong> Sett<strong>in</strong>g time <strong>in</strong> Asam-asam<br />
geopolymers are longer than that <strong>of</strong> Cilacap<br />
geopolymers. It’s also should be reportedthat a<br />
pellets <strong>of</strong> Asam-asam geopolymers with SiO2/Na2O<br />
ratio about 1 at 7 day can not be analyzed because<br />
the result was too small and undetected. In general,<br />
compressive strength related to SiO2/Al2O3 ratio <strong>in</strong><br />
Asam-asam geopolymers was higher than that <strong>of</strong><br />
Cilacap geopolymers and this fact plays an<br />
important to the sett<strong>in</strong>g time <strong>of</strong> geopolymeric<br />
process (De Silva, 2007).<br />
Morphology Analysis<br />
Morphology analysis <strong>of</strong> Cilacap and<br />
Asam-asam geopolymers was shown at Fig. 3. it is<br />
clear that the <strong>in</strong>crease <strong>of</strong> SiO2/Na2O ratio would<br />
.<br />
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decrease heterogenous surface phase and <strong>in</strong>crease<br />
compact region <strong>in</strong> its morphology. This region lies<br />
where dissolution <strong>of</strong> fly ash particle and the<br />
geopolymeric process perfectly take place.<br />
<strong>The</strong> figures. also show that at low<br />
SiO2/Na2O ratio most fly ash particles had been<br />
dissolved, but <strong>in</strong> high SiO2/Na2O ratio many fly ash<br />
particles apparently unreacted. This phenomenon<br />
could be due to low NaOH content at SiO2/Na2O<br />
ratio act<strong>in</strong>g as dissolve<strong>in</strong>g agent <strong>of</strong> fly ash particle .<br />
Beside unreacted ash, many <strong>in</strong>ternal crack<br />
was also found <strong>in</strong> high SiO2/Na2O ratio. Internal<br />
cracks were aris<strong>in</strong>g when the shorten sett<strong>in</strong>g time<br />
geopolymers loose waters at cur<strong>in</strong>g temperature <strong>of</strong><br />
geopolymer pellets. Beside that, Na2SiO3 content<br />
have potential to rise <strong>in</strong>ternal cracks. Hermanus and<br />
Lapu’ (2001) have shown that Na2SiO3 activated<br />
geopolymers giver more crack than NaOH activated<br />
geopolymer. In present study, Na2SiO3 content <strong>in</strong><br />
every geopolymer systems is constant but NaOH<br />
content is varied. Thus, morphology effect <strong>of</strong><br />
Na2SiO3 content <strong>in</strong> high SiO2/Na2O ratio more<br />
apparent than <strong>in</strong> low SiO2/Na2O ratio<br />
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Cilacap<br />
Ci 1 : SiO/Na2O<br />
Ci 1,5 : SiO/Na2O<br />
Ci 2,5 : SiO/Na2O =<br />
Asam-asam<br />
As 1 : SiO/Na2O =<br />
As 1,5 : SiO/Na2O =<br />
Ci 2 : SiO/Na2O = A s 2 : SiO/Na2O =<br />
As 2,5 : SiO/Na2O =<br />
Ci 3 : SiO/Na2O = As 3 : SiO/Na2O =<br />
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Fig. 3 SEM micrograph <strong>of</strong> Cilacap (Ci) and Asam-asam (As) geopolymers at SiO2/Na2O ratio about 1-3.<br />
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(a) (b<br />
(c) (d<br />
Fig. 4. <strong>Zeolite</strong> phase at As 1 (a), As 1,5 (b), Ci 2 (c)<br />
and Ci 3(d)<br />
(<br />
(<br />
Fig. 5. SEM micrograph and square EDX analysis <strong>of</strong> As 1 (a) and Ci<br />
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<strong>The</strong> Effect <strong>of</strong> sodium cation on<br />
geopolymerisation process was shown at SEM-EDX<br />
<strong>of</strong> As 1 and Ci 1 geopolimer (Fig. 5). In l<strong>in</strong>e with<br />
previous explanation by Panias et al.(2006), square<br />
EDX graphic show that sodium cation cause<br />
ungeopolymerized region with uncompact and high<br />
heterogenicity. In the same picture, Al element that<br />
need to geopolimerisation was undetected.<br />
FTIR Analysis<br />
Fig. 6. shows the <strong>in</strong>frared spectroscopy<br />
results for Cilacap fly ash from previous study<br />
Transmitance (%)<br />
<strong>The</strong> band at 995 cm -1 (a) <strong>in</strong> Cilacap orig<strong>in</strong>al ash is<br />
associated with T-O (T=Si,Al) asymmetric<br />
stretch<strong>in</strong>g vibrations. <strong>The</strong> <strong>in</strong>tensity at 457 cm -1 (d) is<br />
associated <strong>in</strong> all cases with T-O bend<strong>in</strong>g vibrations.<br />
<strong>The</strong> band apper<strong>in</strong>g at 780-790 cm -1 (b) corresponds<br />
to the quartz present <strong>in</strong> the orig<strong>in</strong>al fly ash. F<strong>in</strong>ally,<br />
the band at 547 cm -1 (c) corresponds to the mullite<br />
present <strong>in</strong> the ash. After alkal<strong>in</strong>e activated, many<br />
signal appear<strong>in</strong>g at 1093 cm -1 (e) and 996 cm -1 (g)<br />
were attributed, respectively, to the vitreous phase<br />
<strong>of</strong> the quartz and unreacted phase; while the new<br />
component appear<strong>in</strong>g at around 1025 cm -1 (see Fig.<br />
7). Criado (2007) was shown that peaks around<br />
1025-1006 cm -1 <strong>in</strong>dicate the sodium alum<strong>in</strong>o-silicate<br />
gel as result <strong>of</strong> activation.<br />
Investigation <strong>of</strong> sodium cation to<br />
geopolymer product can be seen on Fig. 8. <strong>in</strong> which<br />
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(Tolah, 2008) and the reaction products after<br />
activation (Ci 3). Orig<strong>in</strong>al ash consisted mostly <strong>in</strong> a<br />
vitreous phase compris<strong>in</strong>g SiO2 and Al2O3. <strong>The</strong><br />
presence <strong>of</strong> quartz <strong>in</strong> the fly ash rise the IR spectrum<br />
to a series <strong>of</strong> bands located at 1150, 1084, 796-778,<br />
697, 668, 522 and 460 cm -1 . <strong>The</strong> presence <strong>of</strong> mullite<br />
is responsible for series <strong>of</strong> band at around 1180-<br />
1130 cm -1 and 560-550 cm -1 . Thus, the bands<br />
generated by quartz and mullite <strong>of</strong> the ash show<br />
overlap <strong>in</strong> wavenumber between 1200 and 900 cm -1 (<br />
Criado et al., 2007).<br />
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a<br />
e<br />
f<br />
g<br />
4000 3500 3000 2500 2000 1500 1000 500<br />
Wavenumber (cm -1 )<br />
Ci 3<br />
Cilacap Fly ash<br />
b<br />
c d<br />
Fig. 6. FTIR spectra <strong>of</strong> Cilacap fly ash and Cilacap geopolymer (Ci 3 )<br />
spectra shown quantitative FTIR analysis <strong>of</strong> Cilacap<br />
geopolimer at SiO2/Na2O 1 and 3 is shown.<br />
Furthermore, the lower peak at 3500 cm -1 and the<br />
higher peak at 966 cm -1 <strong>of</strong> Ci 1 than Ci 3<br />
geopolymer <strong>in</strong>dicate to a lot <strong>of</strong> silanol content (Si-<br />
OH that give peak 3500 cm -1 (h)and weak peak at<br />
882 cm -1 (j)) <strong>in</strong> Ci 3. <strong>The</strong> band at region 980-960 cm -<br />
1 , which was <strong>in</strong>vestigated by Lee and Deventer<br />
(2007), <strong>in</strong>dicate Si-O - stretch<strong>in</strong>g vibration that<br />
bond<strong>in</strong>g with alkal<strong>in</strong>e (Na + or K + ). Thus, higher<br />
peak <strong>of</strong> Ci 1 geopolymer at 966 cm - 1(i) shown Si-<br />
ONa stretch<strong>in</strong>g as result higher Na2O. Si-ONa<br />
species gave bad effect, may discont<strong>in</strong>u<strong>in</strong>g, for<br />
geopolymerisation prosess. This is make more<br />
heterogenicity <strong>of</strong> geopolymer and, consequently<br />
lower compressive strength.
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Transmitance (%)<br />
e<br />
f<br />
1200 1150 1100 1050 1000 950 900 850<br />
g<br />
Wavenumber (cm -1 )<br />
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Fig. 7 FTIR Spectra <strong>of</strong> Cilacap geopolymers at wavenumber range 850 -1200 cm -1<br />
k<br />
l<br />
400 600 800 1000 1200 1400<br />
Wavenumber (cm -1 )<br />
As 2.5<br />
Asam-asam fly ash<br />
Fig. 9 . FTIR spectra <strong>of</strong> Asam-asam fly ash and Asam-asam geopolymer (2.5)<br />
Asam-asam fly ash and geopolymer spectra<br />
can be seen at Fig.9. Asam-asam fly ash shown that<br />
wide peak <strong>in</strong> region 1400-827 cm -1 <strong>in</strong>dicate<br />
overlapp<strong>in</strong>g peaks which generated by quartz,<br />
mullite and vitreous phase <strong>of</strong> fly ash. <strong>The</strong> weak<br />
peaks at 790 cm -1 (l) and 461 cm -1 (k) were <strong>in</strong>dicate,<br />
respectively, T-O stretch<strong>in</strong>g <strong>of</strong> mullite and quartz<br />
(Panias et al.,2006). Fig.10. shows same<br />
phenomenon with Fig.8, where As 1 spectra have<br />
lower peak at 3500 cm -1 (m) and higher peak at 980<br />
cm -1 (n) than As 2,5 spectra. In this quantitative<br />
analysis <strong>of</strong> As 1 and As 2,5 were choosen as,<br />
respectively, the lowest and the highest<br />
compressive strength Asam-asam geopolymers,<br />
respectively.<br />
Proceed<strong>in</strong>g Book 491
<strong>The</strong> First International Sem<strong>in</strong>ar on Science and Technology<br />
January 24, 2009<br />
Conclusions<br />
Transmitance (cm -1 )<br />
30<br />
25<br />
20<br />
15<br />
10<br />
5<br />
0<br />
n<br />
0 500 1000 3000 3500 4000 4500 5000 5500<br />
m<br />
Wavenumber (cm -1 )<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
As 1<br />
As 2.5<br />
Fig. 8 Quantitative analysis <strong>of</strong> FTIR to Asam-asam geopolymer at SiO2/Na2O 1 and 2.5.<br />
Follow<strong>in</strong>g conclusions can be made from<br />
this study.<br />
1. <strong>The</strong> <strong>in</strong>itial molar constants <strong>of</strong> Na2O, SiO2 and<br />
Al2O3 were given <strong>in</strong>fluence for geopolymers<br />
product.<br />
2. <strong>The</strong> Na2O content <strong>of</strong> geopolymer plays a key<br />
part <strong>in</strong> dissolv<strong>in</strong>g fly ash particle, but <strong>in</strong><br />
<strong>in</strong>higher content, it affects the compressive<br />
strength and its microstructure.<br />
3. Increase <strong>in</strong> SiO2/Na2O ratio for geopolymers<br />
system, relatively, will <strong>in</strong>crease compressive<br />
strength and make geopolymer microstructure<br />
more compact and homogen.<br />
4. Sodium cation, at high content, can <strong>in</strong>fluence<br />
geopolymer process as detected by FTIR<br />
quantitative analysis.<br />
Acknowledgement<br />
the authors thank to Directorate <strong>of</strong> high<br />
education republic <strong>of</strong> Indonesia for f<strong>in</strong>ancial support<br />
HIBAH PASCASARJANA Program.<br />
Reference<br />
Alfiyah, A., 2008, Synthesis and Characterization <strong>of</strong><br />
Semen Gresik Ltd. Fly Ash-Based Geopolimer,<br />
Chemistry department Faculty <strong>of</strong> Mathematics<br />
and Natural Sciences Sepuluh Nopember Institut<br />
<strong>of</strong> Technology, Surabaya.<br />
Álvarez-ayuso, E., Querol, X., Plana, F., Vázquez,<br />
E. dan Barra, M., 2007, Enviromental, Physical,<br />
and structural characterization <strong>of</strong> Geopolymer<br />
Matrixes Synthesisd from coal (co)combustion<br />
fly ashes, Journal <strong>of</strong> Hazardous Material 154,<br />
175-183.<br />
And<strong>in</strong>i, S., Ci<strong>of</strong>fi, R., Montagnaro, F. dan Santoro,<br />
L.,2007, Coal Fly Ash as Raw Mmaterial for<br />
the Manufacture <strong>of</strong> Geopolymer-based<br />
Products, Waste Management 28, 416-423.<br />
Criado, M., Fernández-Jiménez, A. dan Palomo, A.,<br />
2007, Alkali Activation <strong>of</strong> Flyash: Effect <strong>Study</strong><br />
<strong>of</strong> the SiO2/Na2O Ratio (FTIR study part I),<br />
Microporous and Mesoporous Materials 106,<br />
180-191.<br />
Davidovits, J., 1979, SPE PATEC ’79, Society <strong>of</strong><br />
Plastic Eng<strong>in</strong>eer<strong>in</strong>g, Brookfield Center, USA.<br />
Davidovits, J., 1994, Gepolymers: Man-Made Rock<br />
Geosynthesis and the Result<strong>in</strong>g Development<br />
<strong>of</strong> Very Early High Strength Cement,<br />
Journals <strong>of</strong> Materials and Education 16, 91-<br />
137.<br />
Davidovits, J., 2005, Geopolymer Chemistry and<br />
Susta<strong>in</strong>able Development. the Poly(Sialate)<br />
Term<strong>in</strong>ology: a very useful and simple model<br />
for the promote and understand<strong>in</strong>g <strong>of</strong><br />
greenchemistry, Proceed<strong>in</strong>g <strong>of</strong> the World<br />
Proceed<strong>in</strong>g Book 492
<strong>The</strong> First International Sem<strong>in</strong>ar on Science and Technology<br />
January 24, 2009<br />
Congress Geopolymer, Sa<strong>in</strong>t Quent<strong>in</strong>, France,<br />
28 june-1 july, 111-121.<br />
De Silva, P., Sagoe-Crenstil, K. dan Sirivivatnanon,<br />
V., 2007, K<strong>in</strong>etics <strong>of</strong> Geopolymerization: role<br />
<strong>of</strong> Al2O3 and SiO2, Cement and Concrete<br />
Research 37, 512-518.<br />
Duxson, P., Provis, J.L., Lukey, G.C., Kriven, M.W.<br />
dan van Deventer, J.S.J., 2005, Microstructural<br />
Characterisation <strong>of</strong> Metakaol<strong>in</strong>-Based<br />
Geopolymer. Ceramic Transactions 165, 71-85.<br />
Hermanus, P.A.Y., and lapu’, A.S., 2001, Behaviour<br />
<strong>of</strong> Bottom Ash for Aspalt Concrete Component,<br />
department <strong>of</strong> Civil Eng<strong>in</strong>ee<strong>in</strong>g Christian Petra<br />
University, Surabaya.<br />
Fernández-Jiménez, A.M. dan Palomo, A., 2003,<br />
Characterisation <strong>of</strong> Fly Ash : potensial<br />
reactivityas alkal<strong>in</strong>e cements, Fuel 82, 2259-<br />
2264.<br />
Fernández-Jiménez, A.M. dan Palomo, A., 2005,<br />
Composition and Microstructure <strong>of</strong> Alkali<br />
Activated Fly Ash B<strong>in</strong>der : effect <strong>of</strong> the<br />
activator, Cement and Concrete Research 35,<br />
1984-1992.<br />
Komnitsas, K. dan Zaharaki, D., 2007,<br />
Geopolymerisation: a review and prospect for<br />
the m<strong>in</strong>erals <strong>in</strong>dustry, M<strong>in</strong>erals Eng<strong>in</strong>eer<strong>in</strong>g 20,<br />
1261-1277.<br />
Lee, W.K.W. dan van Deventer, J.S.J., 2007,<br />
Chemical Interactions between Siliceous<br />
Aggregatesan and Low-Ca Alkali-activated<br />
Cemant, Cement and Concrete Research 37,<br />
844-855.<br />
Lodeiro, G., Palomo, A. dan Fernández-Jiménez, A.,<br />
2006, Alkali-Aggregat Reaction <strong>in</strong> Activated<br />
Fly Ash Systems, Cement and Concrete<br />
Research 37, 175-183.<br />
Mulyanto, H., 2008, Mixed Geopolymer from Semen<br />
Gresik Ltd., Cilacap Power Plant and Asamasam<br />
Power Plant Fly Ash, Chemistry<br />
department Faculty <strong>of</strong> Mathematics and Natural<br />
Sciences Sepuluh Nopember Institut <strong>of</strong><br />
Technology, Surabaya.<br />
Muslihah, 2008, Synthesis and Characterization <strong>of</strong><br />
Mixed Geopolymers from Semen Gresik Ltd. and<br />
Asam-asam Power Plant Fly Ash, Chemistry<br />
department Faculty <strong>of</strong> Mathematics and Natural<br />
Sciences Sepuluh Nopember Institut <strong>of</strong><br />
Technology, Surabaya.<br />
Panias, D., Giannopoulou, I.P. dan Perraki, Th.,<br />
2006, Effect <strong>of</strong> Synthesis parameters on<br />
Mechanical Properties <strong>of</strong> Fly Ash-Based<br />
Geopolymers, Colloids and Surfaces Area :<br />
Physicochemistry Eng<strong>in</strong>eer<strong>in</strong>g Aspects.<br />
Accepted Manuscript.<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
Rangan, B.V., Hardjito, D., Wallah, S.E.,<br />
Sumajouw, D.M.J., 2005, Studies on fly ashbased<br />
geopolymer concrete, Proceed<strong>in</strong>gs <strong>of</strong> the<br />
World Congress Geopolymer, Sa<strong>in</strong>t Quent<strong>in</strong>,<br />
France, 28 June – 1 July, pp. 133–137.<br />
Schmücker, M. dan Mackenzie, K.J.D., 2005,<br />
Microstructure <strong>of</strong> Sodium Polysialate Siloxo<br />
Geopolymer, Ceramic International 31, 433-<br />
437.<br />
Swanepoel, J.C dan Strydom, C.A., 2002,<br />
Utillisation <strong>of</strong> Fly Ash <strong>in</strong> a Geopolymeric<br />
Material, Applied Geochemistry 17, 1143-<br />
1148.<br />
Van Jaarsveld, J.G.S. dan van Deventer, J.S.J.,1999,<br />
Effect <strong>of</strong> Metal Alkali Activator on the<br />
Properties <strong>of</strong> Fly Ash-Based Polymers,<br />
Industrial Eng<strong>in</strong>eer<strong>in</strong>g Chemistry Research 38,<br />
3932-3941.<br />
Van Jaarsveld, J.G.S. dan van Deventer, J.S.J.,2003,<br />
<strong>The</strong> Characterization <strong>of</strong> Source Materials <strong>in</strong><br />
Fly Ash-Based Geopolymer, Materials Latters<br />
57, 1272-1280.<br />
Xu, H. dan van Deventer, J.S.J., 2002.<br />
Microstructural Characteristion <strong>of</strong><br />
Geopolymers Synthesised from<br />
Kaol<strong>in</strong>ite/Stilbite Us<strong>in</strong>g XRD, MAS-<br />
NMR,SEM?EDX,TEM/EDX and HREM,<br />
Cement and Concrete Research 32, 1705-1716.<br />
Xu, H., van Deventer, J.S.J., Lukey, G.C., 2001.<br />
Effect <strong>of</strong> Alkali Metal on the Preferential<br />
Geopolymerisation <strong>of</strong> Stilbite/Kaol<strong>in</strong>ite<br />
Mixtures. Industrial Eng<strong>in</strong>eer<strong>in</strong>g Chemistry<br />
Research 40, 3749-3756.<br />
Proceed<strong>in</strong>g Book 493
<strong>The</strong> First International Sem<strong>in</strong>ar on Science and Technology<br />
January 24, 2009<br />
Synthesis and Characterization NiO/TS-1 Catalyst<br />
Siti Qamariyah Khairunisa and Didik Prasetyoko<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
Laboratorium <strong>of</strong> Inorganic Chemistry, Department <strong>of</strong> Chemistry, Faculty <strong>of</strong> Mathematic and Sciences, Institut<br />
Teknologi Sepuluh Nopember (<strong>ITS</strong>), Surabaya, Indonesia.<br />
1) Correspond<strong>in</strong>g author, Phone: +62-85-649808681<br />
email: skhairunisa@gmail.com and didikp@chem.its.ac.id<br />
Introduction<br />
Abstract<br />
Hydroxylation <strong>of</strong> phenol to hydroqu<strong>in</strong>one and catechol is an important reaction for many <strong>in</strong>dustrial<br />
applications, such as: photographic film developer, antioxidant, polymerization <strong>in</strong>hibitor, medic<strong>in</strong>es,<br />
perfumes, and etc. <strong>The</strong> production <strong>of</strong> hydroqu<strong>in</strong>one and catechol from hydroxylation <strong>of</strong> phenol can be<br />
produced by us<strong>in</strong>g homogeneous catalyst. However, this process is not efficient because need separation<br />
between reactant, product, and catalyst. <strong>The</strong> alternative <strong>of</strong> this process is used Titanium Silicalite (TS-1)<br />
as heterogeneous catalyst . TS-1 has great properties, such as high activity and selectivity to oxidation<br />
reaction and green chemistry. Because TS-1 is hydrophobic, so the reaction rate <strong>of</strong> whole reaction is<br />
low. <strong>The</strong> presence <strong>of</strong> nickel oxide on TS-1 can be <strong>in</strong>creased the hydrophilicity and acid sites. NiO/TS-1<br />
was prepared by impregnation method. <strong>The</strong> sample was characterized by XRD, FTIR, and<br />
hydrophobicity techniques. <strong>The</strong> XRD analysis <strong>of</strong> NiO/TS-1 revealed that the MFI structure <strong>of</strong> the TS-1<br />
support was found to be <strong>in</strong>tact <strong>in</strong>corporation <strong>of</strong> nickel oxide. <strong>The</strong> <strong>in</strong>frared spectra showed that the<br />
tetrahedral titanium <strong>in</strong> the TS-1 is still rema<strong>in</strong>ed after impregnation with nickel oxide. <strong>The</strong><br />
hydrophilicity <strong>of</strong> the modified samples <strong>in</strong>creased as a function <strong>of</strong> the amount <strong>of</strong> nickel oxide load<strong>in</strong>g, on<br />
contrary with XRD peak <strong>in</strong>tensity.<br />
Key words: Hydrophobicity, NiO/TS-1, Microporous material<br />
Hydroxylation <strong>of</strong> Phenol to hydroqu<strong>in</strong>one and<br />
catechol is an important reaction for many <strong>in</strong>dustrial<br />
applications, such as: photographic film developer,<br />
antioxidant, polymerization <strong>in</strong>hibitor, medic<strong>in</strong>es,<br />
perfumes, and etc [1]. Dihydroxybenzenes are<br />
largely used today as <strong>in</strong>termediate chemicals. <strong>The</strong>y<br />
are produced by decomposition <strong>of</strong> diisopropyl<br />
benzenes hydroperoxides or by hydroxylation <strong>of</strong><br />
phenol <strong>in</strong> strong acid. Hydroqu<strong>in</strong>one (pdihydroxybenzene)<br />
was also produced by the<br />
oxidation <strong>of</strong> anil<strong>in</strong>e us<strong>in</strong>g manganese dioxide and<br />
sulfuric acids. This was then followed by reduction<br />
us<strong>in</strong>g typically Fe/HCl [2]. This is homogenous<br />
catalytic process, the disadvantage found <strong>in</strong> case <strong>of</strong><br />
homogeneous catalytic process is be<strong>in</strong>g highly<br />
expensive and hydroxylation <strong>of</strong> phenol gives very<br />
low para to ortho ratio [3]. But the use<br />
heterogeneous catalyst is a promis<strong>in</strong>g alternative to<br />
over come this problem. So many works have been<br />
done to enhance the production <strong>of</strong> hydroqu<strong>in</strong>one and<br />
cathecol due to importance <strong>in</strong> <strong>in</strong>dustrial. Titanium<br />
silicalite molecular-sieves (TS-1) for hydroxylation<br />
<strong>of</strong> phenol with hydrogen peroxide as the oxidant was<br />
discovered <strong>in</strong> 1983 by Taramasso et al. and s<strong>in</strong>ce<br />
then it has gradually been acknowledged as one<br />
milestone <strong>in</strong> heterogeneous catalysis. This reaction is<br />
environmentally friendly because only produce water<br />
as by-product. In addition, hydrogen peroxide is a<br />
stable reagent with high active oxygen [4]. One <strong>of</strong><br />
the advantages <strong>of</strong> TS-1 is higher para selectivity,<br />
which is attributed to the shape selectivity <strong>of</strong> the<br />
catalyst. Another advantage <strong>of</strong> this catalyst is the<br />
higher phenol conversion and the low amount <strong>of</strong> tar<br />
formation [5]. <strong>The</strong> conversion <strong>of</strong> hydroxylation <strong>of</strong><br />
phenol with hydrogen peroxide catalyzed by TS-1<br />
obta<strong>in</strong>ed 97% [6].<br />
From the unique properties, TS-1 has<br />
hydrophobic nature. <strong>The</strong> hydrophobicity nature <strong>of</strong><br />
TS-1 can be decreased by <strong>in</strong>corporation <strong>of</strong> metal<br />
oxide. It has been reported that the presence <strong>of</strong> metal<br />
oxide even <strong>in</strong> very small amount can be <strong>in</strong>creased the<br />
catalytic activity due to hydrogen peroxide with TS-<br />
1 formed Ti-peroxo easily. Though hydrophilicity<br />
<strong>in</strong>creases, acid sites also <strong>in</strong>creases. Acid sites<br />
(Brønsted and Lewis) can be found <strong>in</strong> some<br />
transition metals such as metal oxide <strong>of</strong> V2O5,<br />
Nb2O5, MoO3, WO3, Re2O7, NiO, ZnO, Fe2O3,<br />
Cr2O3, dan Cr2O3/Al2O3 [7]. <strong>The</strong> use <strong>of</strong><br />
heterogeneous catalysts is an alternative for<br />
oxidation reactions due to more effective than<br />
homogeneous catalysts. <strong>The</strong> other heterogeneous<br />
catalysts for hydroxylation phenol are CuO–MCM–<br />
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January 24, 2009<br />
48 [8], V2O5/Nd2O3 [9], Cu–VSB–5 [10],<br />
molibdovanad<strong>of</strong>osfor/ZrO2 [3], Fe–HMS [11].<br />
<strong>The</strong> <strong>in</strong>creased <strong>of</strong> load<strong>in</strong>g nickel oxide ca be<br />
<strong>in</strong>creased catalytic activity for dimerization and<br />
isomerization <strong>of</strong> olef<strong>in</strong>s [12]. It has been reported<br />
that the impregnation <strong>of</strong> MoO3 on TS-1 can be<br />
<strong>in</strong>creased hydrophilicity and acid sites, therefore, its<br />
catalytic activity for hydroxylation <strong>of</strong> phenol also<br />
<strong>in</strong>creased [13]. <strong>The</strong> conversion <strong>of</strong> phenol on<br />
MoO3/TS-1 catalyst is higher than TS-1 catalyst was<br />
reported [14].<br />
In this paper, nickel oxide has been loaded on<br />
the surface <strong>of</strong> TS-1 to <strong>in</strong>troduce acidity.<br />
Commonly, <strong>in</strong> the TS-1 structure, titanium was<br />
<strong>in</strong>itially assumed to occupy a substitute position <strong>in</strong><br />
the zeolite framework, s<strong>in</strong>ce XRD measurements<br />
<strong>in</strong>dicated that unit cell volume <strong>in</strong>creases l<strong>in</strong>early<br />
with the Ti content, <strong>in</strong> good agreement with the<br />
isomorphous substitution <strong>of</strong> Ti for Si at tetrahedral<br />
framework sites. However, the local environment<br />
<strong>of</strong> Ti <strong>in</strong> TS-1 can studied us<strong>in</strong>g several techniques<br />
such as FTIR. <strong>The</strong> hydrophobicity <strong>of</strong> TS-1 can<br />
studied us<strong>in</strong>g hydrophobicity tests us<strong>in</strong>g the<br />
mixture <strong>of</strong> xylene and water.<br />
Materials and Methods<br />
Sample<br />
Titanium silicalite<br />
(TS-1)<br />
Table 1: <strong>The</strong> sample code and preparation method<br />
<strong>The</strong> code <strong>of</strong><br />
sample<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
TS-1 was prepared accord<strong>in</strong>g to a procedure<br />
described <strong>in</strong> the literature [15] with slight<br />
modification, us<strong>in</strong>g tetraethyl orthosilicates TEOS<br />
(Merck 98%), tetraethyl orthotitanate TEOT<br />
(Merck 95%) <strong>in</strong> isopropyl alcohol,<br />
tetrapropylammonium hydroxide (Merck 20%<br />
TPAOH <strong>in</strong> water), and distilled water. <strong>The</strong> gel was<br />
charged <strong>in</strong>to 300 ml autoclave and heated at 175 o C<br />
under static condition. <strong>The</strong> material was recovered<br />
after 4 days by centrifugation and washed with<br />
excess distilled water. A white powder was<br />
obta<strong>in</strong>ed after dry<strong>in</strong>g <strong>in</strong> air at 100 o C overnight. <strong>The</strong><br />
calc<strong>in</strong>ations <strong>of</strong> sample to remove the template was<br />
carried out <strong>in</strong> air at 550 o C for 5 hour with<br />
temperature rate 1 o m<strong>in</strong>-1.<br />
Sample NiO/TS-1, TS-1 loaded with nickel<br />
oxide (0.5; 1; 2; 4) were prepared by impregnation<br />
technique us<strong>in</strong>g Ni(NO3)2 as a precursor. About<br />
0.0126 g <strong>of</strong> Ni(NO3)2 was dissolved <strong>in</strong> distilled<br />
water to obta<strong>in</strong> the desired metal load<strong>in</strong>g and<br />
required quantity <strong>of</strong> pre-dried <strong>of</strong> TS-1 was<br />
immediately added to clear solution with stirr<strong>in</strong>g.<br />
<strong>The</strong> mixture was stirred at room temperature for 3<br />
hour. <strong>The</strong> solid was recovered by evaporat<strong>in</strong>g the<br />
distilled water at 80 o C. <strong>The</strong> solid was then dried at<br />
100 o C for 24 hour. <strong>The</strong>n solid was calc<strong>in</strong>ed at 500<br />
o C for 5 hour with temperature rate 1 o m<strong>in</strong> -1 . <strong>The</strong><br />
method and compositions <strong>of</strong> the samples are listed<br />
<strong>in</strong> Table 1.<br />
NiO/(NiO+TS-1),% Method<br />
TS-1 1 *(gel) hydrothermal<br />
0.5% NiO/TS-1 0.5NiO/TS-1 0.5 Impregnation- hydrothermal<br />
1% NiO/TS-1 1NiO/TS-1 1 Impregnation- hydrothermal<br />
2% NiO/TS-1 2NiO/TS-1 2 Impregnation- hydrothermal<br />
4% NiO/TS-1 4NiO/TS-1 4 Impregnation- hydrothermal<br />
NiO NiO 100 calc<strong>in</strong>ation<br />
* (%Ti) = Ti/(Ti+Si)<br />
All molecular sieves were characterized by<br />
powder X-ray diffraction (XRD) for identification<br />
<strong>of</strong> the crystall<strong>in</strong>e phases <strong>in</strong> the catalysts us<strong>in</strong>g<br />
diffractometer with the Cu Kα (λ = 1.5405 Å)<br />
radiation as the diffracted monochromatic beam at<br />
40 kV dan 40 mA. Typically, powder sample were<br />
ground and spread <strong>in</strong>to a sample holder and then<br />
analyzed. <strong>The</strong> pattern was scanned <strong>in</strong> the 2θ range<br />
<strong>of</strong> 5–50 o at step 0.020o and step time 1 second.<br />
Infrared (IR) spectra <strong>of</strong> samples were collected on a<br />
Perk<strong>in</strong> Elmer Fourier Transform Infrared (FTIR)<br />
spectrophotometer, with a spectral were recorded <strong>in</strong><br />
the region <strong>of</strong> 1400 – 400 cm -1 . Hydrophobicity test<br />
were determ<strong>in</strong>ed by the mixture <strong>of</strong> xylene and<br />
water, which do not mix each other. Xylene and<br />
water <strong>of</strong> the same volume are added <strong>in</strong>to a test tube<br />
to form a stable phase <strong>in</strong>terface, as shown <strong>in</strong> figure<br />
1. TS-1 and NiO/TS-1 samples were dispersed <strong>in</strong><br />
the xylene-water system and stirred. After the<br />
mixture has stabilized, hydrophobic characteristics<br />
can be qualitatively evaluated by <strong>in</strong>spect<strong>in</strong>g the<br />
state <strong>of</strong> the float<strong>in</strong>g/s<strong>in</strong>k<strong>in</strong>g <strong>of</strong> samples pass the<br />
phase <strong>in</strong>terface and s<strong>in</strong>k<strong>in</strong>g <strong>of</strong> samples at the<br />
<strong>in</strong>terface. <strong>The</strong> criteria <strong>of</strong> hydrophobic <strong>in</strong>dex is as<br />
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follows: (1) hydrophilic: samples pass the phase<br />
<strong>in</strong>terface and s<strong>in</strong>k <strong>in</strong>to water quickly and<br />
completely; (2) hydrophilic: samples pass the phase<br />
<strong>in</strong>terface and s<strong>in</strong>k <strong>in</strong>to water not so quickly; (3)<br />
hydrophilic: samples float at first on the phase<br />
<strong>in</strong>terface and then s<strong>in</strong>k <strong>in</strong>to water slowly and<br />
completely; (4) partially hydrophilic: samples float<br />
Results and Discussion<br />
X-ray Diffraction (XRD)<br />
Xylene<br />
Interface<br />
Water<br />
<strong>The</strong> XRD pattern <strong>of</strong> the samples are shown<br />
Figure 2, while the phase conta<strong>in</strong><strong>in</strong>g sample are<br />
tabulated <strong>in</strong> Table 2. <strong>The</strong> XRD pattern <strong>of</strong> TS-1 and<br />
NiO/TS-1 sample <strong>in</strong>dicated that the sample<br />
conta<strong>in</strong>ed framework structures <strong>of</strong> the MFI type<br />
zeolite. <strong>The</strong> XRD pattern showed the framework<br />
structures <strong>of</strong> the MFI at 2θ = 8.00; 8.88; 23.12;<br />
23.18; 23.44; 23.74°. <strong>The</strong> peak at 2θ = 24.45º<br />
<strong>in</strong>dicated a chang<strong>in</strong>g <strong>of</strong> a monocl<strong>in</strong>ic symmetry<br />
(silicalite) to an orthorhombic symmetry (titanium<br />
silicalite, TS-1) [17]. For sample NiO/TS-1, the<br />
structure <strong>of</strong> TS-1 is not strongly affected by the<br />
presence <strong>of</strong> impregnated nickel oxide. <strong>The</strong> XRD<br />
pattern showed that no diffraction l<strong>in</strong>e assigned for<br />
Figure 1. Test<strong>in</strong>g <strong>of</strong> hydrophobic nature <strong>of</strong> sample<br />
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at first on the phase <strong>in</strong>terface and then some<br />
particles s<strong>in</strong>k <strong>in</strong>to water completely; (5) partially<br />
hydrophobic: samples float on the phase <strong>in</strong>terface.<br />
After mix<strong>in</strong>g a long time, some particles still float<br />
on the phase <strong>in</strong>terface; and (6) completely<br />
hydrophobic: samples float on the phase <strong>in</strong>terface<br />
even with vigorous mix<strong>in</strong>g for along time [16].<br />
crystall<strong>in</strong>e phase <strong>of</strong> the nickel oxide were<br />
<strong>in</strong>vestigated. This <strong>in</strong>dicated that nickel was well<br />
dispersed on the TS-1. <strong>The</strong> peak <strong>in</strong>tensity <strong>of</strong><br />
NiO/TS-1 with various load<strong>in</strong>g is drastically<br />
decreased as addition <strong>of</strong> nickel oxide <strong>in</strong>creased. It is<br />
suggested that nickel is either located on the surface<br />
<strong>of</strong> TS-1 or cover<strong>in</strong>g the surface <strong>of</strong> TS-1.<br />
Table 2 <strong>The</strong> crystall<strong>in</strong>ity <strong>of</strong> TS-1 and NiO/TS-1<br />
samples<br />
Code sample<br />
Intensity at<br />
2θ = 23.18, a.u<br />
Phase<br />
TS-1<br />
3083 MFI<br />
0,5 NiO/TS-1<br />
3035 MFI<br />
1 NiO/TS-1<br />
2720 MFI<br />
2 NiO/TS-1<br />
2598 MFI<br />
4 NiO/TS-1<br />
2563 MFI<br />
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Intensity, a.u.<br />
5.00 15.00 25.00 35.00 45.00<br />
2 theta, degree<br />
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4NiO/TS-1<br />
2NiO/TS-1<br />
1NiO/TS-1<br />
0.5NiO/TS-1<br />
TS-1<br />
NiO<br />
Figure 2 XRD pattern <strong>of</strong> the NiO, TS-1, and XNiO/TS-1 samples<br />
Fourier Transform Infrared (FTIR) Spectroscopy<br />
<strong>The</strong> <strong>in</strong>frared spectra <strong>of</strong> the samples <strong>in</strong> the<br />
lattice vibration region between 1400 and 400 cm -1<br />
are depicted <strong>in</strong> figure 3. Sample TS-1 and<br />
XNiO/TS-1 showed similar bands. Accord<strong>in</strong>g to<br />
Flanigen [18], the absorption bands at around 1100,<br />
800, and 450 cm -1 were three lattice modes<br />
associated with <strong>in</strong>ternal l<strong>in</strong>kages <strong>in</strong> tetrahedral SiO4<br />
and are <strong>in</strong>sensitive to structure changes. <strong>The</strong><br />
absorption bands at about 1225 and 547 cm -1 are<br />
characteristic <strong>of</strong> MFI type zeolite associated with<br />
the particular structural assembly <strong>of</strong> the tetrahedral<br />
and are sensitive to structure changes. It is already<br />
known that the <strong>in</strong>frared spectrum <strong>of</strong> titanium<br />
silicalite, TS-1 is characterized by an absorption<br />
band at around 960 cm -1 . However, the vibrational<br />
modes at around this frequency may be the result <strong>of</strong><br />
several contributions i.e. the asymmetric stretch<strong>in</strong>g<br />
modes <strong>of</strong> Si-O-Ti l<strong>in</strong>kages, term<strong>in</strong>al Si-O stretch<strong>in</strong>g<br />
<strong>of</strong> SiOH-(HO)Ti “defective sites” and titanyl<br />
[Ti=O] vibrations [19]. Our TS-1 sample shows a<br />
weak band at 970 cm -1 . This band can be attributed<br />
to the titanium <strong>in</strong> the framework and with addition<br />
NiO<br />
<strong>of</strong> nickel oxide onto TS-1 by impregnation still<br />
show band at 970 cm -1 . It <strong>in</strong>cluded that TS-1 and<br />
NiO/TS-1 sample conta<strong>in</strong>s Si-O-Ti connections.<br />
In addition, a small band at around 970<br />
cm -1 assigned to the titanium ions <strong>in</strong> the tetrahedral<br />
structure is still present after impregnation <strong>of</strong> nickel<br />
(NiO/TS-1). No additional band after impregnation<br />
<strong>of</strong> nickel <strong>in</strong>to the TS-1 can be observed. This<br />
f<strong>in</strong>d<strong>in</strong>g shows that impregnation <strong>of</strong> nickel has not<br />
effected the MFI structure <strong>of</strong> TS-1 significantly.<br />
Meanwhile, <strong>in</strong>frared spectroscopy technique cannot<br />
detect the presence <strong>of</strong> nickel oxide <strong>in</strong> the sample<br />
NiO/TS-1, due to addition nickel oxide <strong>in</strong>to TS-1 is<br />
low. However, the frequency <strong>of</strong> bands decreased as<br />
the amount <strong>of</strong> load<strong>in</strong>g nickel oxide <strong>in</strong> the<br />
<strong>in</strong>vestigated samples <strong>in</strong>creased.<br />
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Transmittance, %<br />
1100 970<br />
Wave number cm -1<br />
1400 1200 1000 800 600<br />
400<br />
Hydrophobicity Tests<br />
<strong>The</strong> results <strong>of</strong> hydrophobic tests are shown <strong>in</strong><br />
the Table 3. From Table 3, it can be seen that TS-1<br />
sample is strongly hydrophobic, while NiO/TS-1<br />
samples are more hydrophilic than TS-1. <strong>The</strong> result<br />
<strong>of</strong> hydrophobicity tests with the criterion <strong>of</strong><br />
hydrophobic <strong>in</strong>dex are (1) until (6) [16]. <strong>The</strong><br />
800<br />
550<br />
Figure 3. Spectra FTIR <strong>of</strong> the TS-1, XNiO/TS-1 samples<br />
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459<br />
Table 3. <strong>The</strong> results <strong>of</strong> hydrophobicity tests <strong>of</strong> all samples<br />
4NiO/TS-1<br />
2NiO/TS-1<br />
1NiO/TS-1<br />
0 5NiO/TS-1<br />
TS-1<br />
NiO<br />
purpose <strong>of</strong> this observation <strong>of</strong> time is to compare<br />
hydrophilicity among the samples. <strong>The</strong><br />
<strong>in</strong>corporation <strong>of</strong> nickel oxide can be <strong>in</strong>creased the<br />
hydrophilic nature <strong>of</strong> TS-1. <strong>The</strong> hydrophilicity <strong>of</strong><br />
NiO/TS-1 samples <strong>in</strong>creased as a function <strong>of</strong> nickel<br />
oxide load<strong>in</strong>g, as shown <strong>in</strong> Table 3.<br />
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No. Sample Criterion <strong>of</strong><br />
hydrophobic <strong>in</strong>dex<br />
Time<br />
1. TS-1 5 2 m<strong>in</strong>utes 31 seconds<br />
2. 0.5NiO/TS-1 5 1 m<strong>in</strong>utes 26 seconds<br />
3. 1NiO/TS-1 5 1 m<strong>in</strong>utes 6 seconds<br />
4. 2NiO/TS-1 5 1 m<strong>in</strong>utes 1 seconds<br />
5. 4NiO/TS-1 3 50 seconds<br />
Among all samples, 4NiO/TS-1 sample showed the<br />
faster drop than the other samples, while TS-1 is<br />
the lowest. It is <strong>in</strong>dicated that TS-1 has<br />
hydrophobic character with hydrophobic <strong>in</strong>dex 5.<br />
While 4NiO/TS-1 sample showed strongly<br />
hydrophilic than other samples (Table 3). 4NiO/TS-<br />
1 has hydrophilic character with hydrophobic <strong>in</strong>dex<br />
3, when samples float at first on the phase <strong>in</strong>terface<br />
and then s<strong>in</strong>k <strong>in</strong>to water slowly and completely, as<br />
shown <strong>in</strong> Figure 4e. It <strong>in</strong>dicated the <strong>in</strong>corporation<br />
<strong>of</strong> nickel oxide can be <strong>in</strong>creased the hydrophilicity<br />
<strong>of</strong> TS-1 and can effect <strong>of</strong> catalytic activity. Besides<br />
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that, with the <strong>in</strong>corporation <strong>of</strong> nickel oxide can be<br />
<strong>in</strong>creased Lewis acid site. Lewis acid site can be<br />
effect hydrophilicity <strong>of</strong> TS-1 because can be accept<br />
free electron pairs from water. This is will be<br />
studied further. All samples with hydrophobic<br />
<strong>in</strong>dex 5, before stirr<strong>in</strong>g float on the <strong>in</strong>terface, after<br />
stirr<strong>in</strong>g and keep on overnight some particles still<br />
float on the <strong>in</strong>terface, as shown <strong>in</strong> Figure 4 and 5.<br />
But sample with hydrophobic <strong>in</strong>dex 3, there is no<br />
particles float at the <strong>in</strong>terface before and after<br />
stirr<strong>in</strong>g.<br />
Figure 4: Sample TS-1 (a) and XNiO/TS-1 (X = 0.5, 1, 2, and 4) (b-d) <strong>in</strong> the water-xylene before stirr<strong>in</strong>g.<br />
a b c d e<br />
0.5NiO/TS-1<br />
1NiO/TS-1 2NiO/TS-1 4NiO/TS-1<br />
a b c d e<br />
Figure 5: Sample TS-1 (a) and XNiO/TS-1 (X = 0.5, 1, 2, and 4) (b-d) <strong>in</strong> the water-xylene after stirr<strong>in</strong>g.<br />
Conclusion<br />
NiO/TS-1 catalysts were successfully<br />
synthesized by impregnation <strong>of</strong> nickel oxide on the<br />
surface <strong>of</strong> TS-1. X-ray diffraction <strong>in</strong>dicated that all<br />
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the samples had the MFI crystall<strong>in</strong>e structure. <strong>The</strong><br />
MFI crystall<strong>in</strong>e structure was not changed with the<br />
load<strong>in</strong>g <strong>of</strong> nickel oxide. Infrared spectroscopy<br />
showed band at around 960 cm -1 , attributed to the<br />
titanium <strong>in</strong> the framework and spectra was still<br />
rema<strong>in</strong>ed with the load<strong>in</strong>g <strong>of</strong> nickel oxide. <strong>The</strong><br />
<strong>in</strong>creas<strong>in</strong>g <strong>of</strong> catalyst hydrophobicity depended on<br />
the load<strong>in</strong>g amount <strong>of</strong> nickel oxide.<br />
Acknowledgements<br />
We gratefully acknowledge fund<strong>in</strong>g from the<br />
Directorate General <strong>of</strong> Higher Education,<br />
Indonesia, under Hibah grant.<br />
References<br />
[1] Schudel, P., Mayer, H., Isler, O., Sebrell, W. H.,<br />
Harris, R. S., (1972), Academic Press: New<br />
York, 5: 165 – 317.<br />
[2] Corma, A and Garcia, H, (2002), “Lewis Acid as<br />
Catalysts <strong>in</strong> Oxidation Reactions: From<br />
Homogeneous to Heterogeneous Systems”,<br />
Chem. Rev.<br />
[3] Parida, K. M., Mallick, S., (2008),<br />
“Hydroxylation <strong>of</strong> Phenol Over<br />
Molybdovanadophosphoric Acid Modified<br />
Zirconia”, J. Mol. Catal. A: Chemical, 279:<br />
104-111.<br />
[4] Smith, G. V., Notheisz, F., (1999),<br />
Heterogenous Catalysis <strong>in</strong> Organic<br />
Chemistry, Elsevier.<br />
[5] Bellussi, G., Mill<strong>in</strong>i, R., Previde, M. E., Perego,<br />
G., (1992), “Framework Composition <strong>of</strong><br />
Titanium Silicate-1”, J. Catal., Vol. 137,<br />
Hal. 497-503.<br />
[6] Bianchi, Daniele, Aloisio, D’. R., Bortolo, R.,<br />
Ricci, M., (2007), “Oxidation <strong>of</strong> Mono- and<br />
Bicyclic Aromatic Compounds with<br />
Hydrogen Peroxide Catalyzed by Titanium<br />
Silicates TS-1 and TS-1B”, Appl. Catal. A:<br />
General, 327: 295-299.<br />
[7] Kung, H.H, (1989), “Transition Metal Oxides:<br />
Surface Chemistry and Catalysis, <strong>Study</strong><br />
Surface Science and Catalyst”, Elsevier,<br />
New York. 45.<br />
[8] Lou, L., and Liu, S. (2005), “CuO-Conta<strong>in</strong><strong>in</strong>g<br />
MCM-48 as Catalysts for Phenol<br />
Hydroxylation”, Catal. Commun., 6:762-<br />
765.<br />
[9] Shylesh, S., Radhika, T., Sreeja, K. R.,<br />
Sugunan, S., (2005), “Synthesis,<br />
Characterization and catalytic activity <strong>of</strong><br />
Nd2O3 supported V2O5 catalysts”, J. Mol.<br />
Catal. A: Chemical, 236: 253-259.<br />
[10] Jiang, Y., Gao, Q., (2007), “Preparation <strong>of</strong><br />
Cu2+ - VSB-5 and <strong>The</strong>ir Catalytic Properties<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
on Hydroxylation <strong>of</strong> Phenol”, Mater. Lett.,<br />
61: 2212-2216.<br />
[11] Liu, H., Lu, G., Guo, Y., Guo, Y., Wang, J.,<br />
(2008), “<strong>Study</strong> on <strong>The</strong> Synthesis and <strong>The</strong><br />
Catalytic Properties <strong>of</strong> Fe-HMS Materials <strong>in</strong><br />
<strong>The</strong> Hydroxylation <strong>of</strong> Phenol”, Micro.<br />
Meso. Mater., 108: 56-64.<br />
[12] Rack, J. Sohn, (2002), “Catalytic Activities <strong>of</strong><br />
Nickel-Conta<strong>in</strong><strong>in</strong>g Catalysts for Ethylene<br />
Dimerization and Butene Isomerization and<br />
<strong>The</strong>ir Relationship to Acidic Properties”,<br />
Catal. Today, 73:197-209.<br />
[13] Liu, Y., Ma, X., Wang, S., Gong, J. (2007),<br />
”<strong>The</strong> Nature <strong>of</strong> Surface Acidity and<br />
Reactivity <strong>of</strong> MoO3/SiO2 and MoO3/TiO2-<br />
SiO2 for Transesterification <strong>of</strong> Dimethyl<br />
Oxalate with Phenol: A Comparative<br />
Investigation”, Appl. Catal. B:<br />
Environmental, 77: 125-134.<br />
[14] Indrayani, Suci, (2008), Aktvitas Katalitik<br />
MoO3/TS-1 pada Reaksi Hidroksilasi Fenol<br />
menggunakan H2O2, Tesis, Institut Sepuluh<br />
November, Surabaya.<br />
[15] Taramasso, M., Perego, G., Notari, B. (1983),<br />
“Preparation <strong>of</strong> Porous Crystall<strong>in</strong>e Synthetic<br />
Material Comprised <strong>of</strong> Silicon and Titanium<br />
Oxides”, (U. S. Patents No. 4,410,501).<br />
[16] Wang, Z., Wang, T., Wang, Z., J<strong>in</strong>, Y. (2004),<br />
“Organic modification <strong>of</strong> ultraf<strong>in</strong>e particles<br />
us<strong>in</strong>g carbon dioxide as the solvent”, J.<br />
Powder Technology, 139: 148-155.<br />
[17] Li, Y.G., Lee, Y.M., Porter, J.F. (2002), <strong>The</strong><br />
Synthesis and Characterization <strong>of</strong> Titanium<br />
Silicalite-1, Kluwer Academic Publishers,.<br />
0022-2461.<br />
[18] Flanigen. E. M. (1976), “Structural Analysis<br />
By Infrared Spectroscopy”. In: Rabo, J.<br />
A.ed. <strong>Zeolite</strong> chemistry and catalysis, ACS<br />
Monograph 171: 80-117.<br />
[19] Prasetyoko, D., Ramli, Z., Endud, S., Nur, H.<br />
(2005a), “Preparation and Characterization<br />
<strong>of</strong> Bifunctional Oxidative and Acidic<br />
Catalysts Nb2O5/TS-1 for Synthesis <strong>of</strong><br />
Diols”. Mater. Chem. and Phys., Vol. 93,<br />
hal. 443-449.<br />
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ISBN : 978 – 979 – 19201 – 0 – 0<br />
Coal Fly Ash Geopolymer:<br />
<strong>Study</strong> <strong>of</strong> SiO2/Al2O3 Mol Ratios and the Resulted Geopolymer Properties<br />
Introduction<br />
Ella Kusumastuti 1 , Hamzah Fansuri 2 , Lukman Atmaja 3* ,<br />
1 Chemistry Department, Sepuluh Nopember Institute <strong>of</strong> Technology, Surabaya<br />
2, 3 Chemistry Department, Sepuluh Nopember Institute <strong>of</strong> Technology, Surabaya<br />
* Correspond<strong>in</strong>g author : lukman_at@chem.its.ac.id<br />
Abstract<br />
<strong>The</strong> effect <strong>of</strong> SiO 2/Al 2O 3 mol ratio with the contribution <strong>of</strong> each SiO 2 and Al 2O 3 <strong>in</strong> the reaction<br />
mixture to the chemical and mechanical properties <strong>of</strong> the geopolymer product has ben <strong>in</strong>vestigated.<br />
Type C <strong>of</strong> fly ash from Cilacap Power Plant was used as the based material which had <strong>in</strong>itial mol ratio<br />
SiO 2/Al 2O 3=4.32. Two series <strong>of</strong> variation SiO 2/Al 2O 3 were made by vary<strong>in</strong>g the amount <strong>of</strong> soluble<br />
additives (Na2SiO 3 and Al(OH) 3) added to the <strong>in</strong>itial reaction mixture (fly ash, Na 2SiO 3, NaOH, and<br />
H 2O). All conditions have been done at constant consistency.<br />
<strong>The</strong> results showed that the addition <strong>of</strong> alum<strong>in</strong>ate species at constant silicate and the reduction <strong>of</strong><br />
NaOH molarity <strong>in</strong>crease the sett<strong>in</strong>g time due to more Al(OH)3(H 2O) complex species was available to<br />
<strong>in</strong>hibited polycondensation reaction. <strong>The</strong> optimum compressive strength was achieved at mol ratio <strong>of</strong><br />
SiO2/Al 2O 3=3.0 for Al 2O 3 series and SiO 2/Al 2O 3=5.0 for <strong>of</strong> SiO 2 series. Phase development showed<br />
that the greater SiO2/Al 2O 3 mol ratio, the greater formation <strong>of</strong> amorf homogenous phase and lead to<br />
reach optimum SiO 2/Al 2O 3 mol ratio. FTIR study showed that the greater SiO 2/Al 2O 3 mol ratio, the<br />
greater the wave number <strong>of</strong> vibration mean<strong>in</strong>g both the <strong>in</strong>creas<strong>in</strong>g <strong>of</strong> cha<strong>in</strong> length Si-O-Al or Si-O-Si<br />
and the vibration energy. It also revealed that there were more formation <strong>of</strong> gel alum<strong>in</strong>osilicate <strong>in</strong><br />
geopolimerisation and that the chemical bond <strong>of</strong> Si-O-Al or Si-O-Si gett<strong>in</strong>g strong at optimum<br />
SiO2/Al 2O 3 mol ratio. Gra<strong>in</strong> structure appeared at low SiO 2/Al 2O 3 caus<strong>in</strong>g a lower strength, while<br />
homogenous geopolymer matrix appeared at optimum SiO 2/Al 2O 3 mol ratio cauisng to a higher<br />
strength. Unreacted fly ash and residual reactant appeared at high SiO2/Al 2O 3 mol ratio and lead to a<br />
lower strength.<br />
Keywords: geopolymer, coal fly ash, alum<strong>in</strong>osilicates, SiO 2/Al 2O 3<br />
Efforts for reduc<strong>in</strong>g the world cement consumption<br />
have been developed by synthes<strong>in</strong>g material that<br />
has cementitious properties and potential to<br />
partially replaced conctrete. Davidovits, a scientist<br />
<strong>in</strong> polymer, <strong>in</strong> 1978 for the first time developed<br />
alum<strong>in</strong>osilicate <strong>in</strong>organic polymer called<br />
geopolymer (Davidovits, 1994). Geopolymer which<br />
has general formula nM2O·Al2O3· xSiO2· yH2O was<br />
obta<strong>in</strong>ed from polycondensation reaction <strong>of</strong><br />
pozzolanic materials or alumonosilicate m<strong>in</strong>erals<br />
with alkali silicate solution (Davidovits, 1991).<br />
This relatively new material has a similar<br />
cementitious properties to concrete.<br />
Fly ash, by-product <strong>of</strong> coal-based <strong>in</strong>dustry, has<br />
pozzolanic properties as its major content are<br />
reactive silica and alum<strong>in</strong>a. Thus, it is a good<br />
start<strong>in</strong>g materials to synthesize geopolymer.<br />
Pozzolanic properties describes the reactivity <strong>of</strong><br />
silica and alum<strong>in</strong>a which took a part <strong>in</strong> the<br />
formation <strong>of</strong> Si-O-Al cha<strong>in</strong>s <strong>in</strong> geopolymer.<br />
One <strong>of</strong> major parameters <strong>in</strong> the <strong>in</strong>itial mixture <strong>of</strong><br />
the start<strong>in</strong>g material, <strong>in</strong> the case <strong>of</strong> fly ash, is the<br />
quantity <strong>of</strong> the essential compounds <strong>in</strong>volved <strong>in</strong> the<br />
formation <strong>of</strong> geopolymer cha<strong>in</strong>s. SiO2 and Al2O3<br />
are the major oxides besides the other oxides which<br />
have an important role <strong>in</strong> the formation <strong>of</strong> Si-O-Al<br />
cha<strong>in</strong>s <strong>in</strong> geopolymer. <strong>The</strong> dissolution <strong>of</strong> silica and<br />
alum<strong>in</strong>a <strong>in</strong> the surface <strong>of</strong> fly ash was determ<strong>in</strong>ed by<br />
the chemical composition <strong>of</strong> fly ash itself (Riza<strong>in</strong>,<br />
2008). In the high alkali condition, Al2O3<br />
solubilities were greater than that <strong>of</strong> SiO2 (Swaddle,<br />
2001). In the condition <strong>of</strong> more reactive<br />
SiO2/Al2O3, there would be a different contribution<br />
<strong>of</strong> silica and alum<strong>in</strong>a, i.e., alum<strong>in</strong>a is responsible<br />
for <strong>in</strong>itial properties while silica is for f<strong>in</strong>al<br />
properties.<br />
This research was objected for study<strong>in</strong>g the effect<br />
<strong>of</strong> SiO2/Al2O3 moles ratio hav<strong>in</strong>g contribution <strong>of</strong><br />
each SiO2 and Al2O3 <strong>in</strong> the start<strong>in</strong>g material to the<br />
chemical and mechanical properties <strong>of</strong> the<br />
geopolymer product such as sett<strong>in</strong>g time,<br />
compressive strength, phase development, the<br />
chang<strong>in</strong>g <strong>of</strong> chemical bond and microstructure.<br />
Materials and Method<br />
Fly ash from Cilacap Power Plant was used as the<br />
based material, and NaOH, H2O, sodium silicate<br />
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and alum<strong>in</strong>ium hidroxide were used as additive<br />
(added alum<strong>in</strong>ate species). Some standard<br />
laboratory tools were used to mix and mold the<br />
geopolimer matrixs. X-Ray Fluorescence (XRF)<br />
was used for the determ<strong>in</strong>ation <strong>of</strong> fly ash<br />
composition, while the characterisations <strong>of</strong><br />
geopolymer such as sett<strong>in</strong>g time, compressive<br />
srength and phase development used a Vicat Needle<br />
Apparatus, Universal Test<strong>in</strong>g Mach<strong>in</strong>e and X-Ray<br />
Diffraction (XRD), respectively. Scann<strong>in</strong>g Electron<br />
Microscopy (SEM) was used to <strong>in</strong>vestigate the<br />
morphology and Fourier Transform Infra Red<br />
(FTIR) to <strong>in</strong>vestigate chemical bond <strong>of</strong> the resulted<br />
geopolymer.<br />
At first, geopolymer synthesis has been carried out<br />
by mix<strong>in</strong>g the fly ash with activator (NaOH<br />
solution). <strong>The</strong> <strong>in</strong>itial mix<strong>in</strong>g was done by hands for<br />
2 m<strong>in</strong>utes then by mixer for 5 m<strong>in</strong>utes so the<br />
mixture was really homogenous (van Deventer,<br />
2000 and van Jaarsveld, 2002). <strong>The</strong> mixture then<br />
poured <strong>in</strong>to plastic cil<strong>in</strong>der mold with 1.5 cm <strong>in</strong><br />
diametre and 3 cm <strong>in</strong> high (Bakharev, 2005 and<br />
And<strong>in</strong>i, 2008). Vibration has been done for about<br />
15 m<strong>in</strong>utes to remove air bubble <strong>in</strong> paste so it was<br />
be more dense (Duxson, 2005). <strong>The</strong> result <strong>of</strong><br />
mould<strong>in</strong>g process was let <strong>in</strong> the room temperature<br />
for 2 hours until it could be released from its<br />
mould. It then was sealed/wrapped with plastics to<br />
avoid loos<strong>in</strong>g water quickly which could the pellet<br />
cracked. Pellets then cured at 60°C for 24 hours <strong>in</strong><br />
the oven (Ch<strong>in</strong>daprasirt, 2007 and Aly, 2008) to<br />
maximise the reaction <strong>of</strong> geopolymerisation.<br />
<strong>The</strong> SiO2/Al2O3 mol ratios were made by vary<strong>in</strong>g<br />
the amount <strong>of</strong> soluble additives (Na2SiO3 and<br />
Al(OH)3, respectively) that added to the <strong>in</strong>itial<br />
reaction mixture (fly ash, Na2SiO3, NaOH, and<br />
H2O). Two series <strong>of</strong> variations were used. <strong>The</strong> first<br />
was achieved by vary<strong>in</strong>g Al2O3 content at constant<br />
SiO2 and the other was achied by vary<strong>in</strong>g SiO2<br />
content at constant Al2O3. <strong>The</strong> amount <strong>of</strong> Na2O <strong>in</strong><br />
all variations was kept constant. Water was added<br />
to achieve the same mixture consistency <strong>in</strong> all<br />
variations.<br />
<strong>The</strong> total moles <strong>in</strong> every composition were<br />
presented below :<br />
Table 1 <strong>The</strong> Total Moles <strong>in</strong> Variation <strong>of</strong> Al2O3 at<br />
Constant SiO2<br />
Total Moles<br />
SiO2 Al2O3 Na2O<br />
SiO2/Al2O3<br />
0.217 0.434 0.113 0.5<br />
0.217 0.217 0.113 1.0<br />
0.217 0.145 0.113 1.5<br />
0.217 0.109 0.113 2.0<br />
0.217 0.087 0.113 2.5<br />
0.217 0.072 0.113 3.0<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
0.217 0.062 0.113 3.5<br />
0.217 0.054 0.113 4.0<br />
0.217 0.048 0.113 4.5<br />
0.217 0.043 0.113 5.0<br />
0.217 0.043 0.113 5.064<br />
Table 2 <strong>The</strong> Total Moles <strong>in</strong> Variation <strong>of</strong> SiO2 at<br />
Constant Al2O3<br />
Total Moles<br />
SiO2 Al2O3 Na2O<br />
SiO2/Al2O3<br />
0.021 0.043 0.113 0.5<br />
0.043 0.043 0.113 1.0<br />
0.064 0.043 0.113 1.5<br />
0.086 0.043 0.113 2.0<br />
0.107 0.043 0.113 2.5<br />
0.129 0.043 0.113 3.0<br />
0.150 0.043 0.113 3.5<br />
0.171 0.043 0.113 4.0<br />
0.193 0.043 0.113 4.5<br />
0.214 0.043 0.113 5.0<br />
0.217 0.043 0.113 5.064<br />
<strong>The</strong> gepolymer pellets then were characterized for<br />
study<strong>in</strong>g the chemical properties after cured for 28<br />
days (Hardjito, 2004). <strong>The</strong> mechanical properties<br />
were determ<strong>in</strong>ed after 1 and 28 days.<br />
Result and Discussion<br />
Fly ash Characterization<br />
<strong>The</strong> composition <strong>of</strong> fly ash from Cilacap Power<br />
Plant is presented <strong>in</strong> Table 3. It can be seen that the<br />
major oxides <strong>of</strong> the fly ash were SiO2, Al2O3, CaO<br />
and Fe2O3. This fact lead to catagoris<strong>in</strong>g the fly ash<br />
as class C.<br />
Phase analysis by XRD showed that the phase<br />
majority was quartz (SiO2) and mullite (3Al2O3<br />
xSiO2) and albite (NaAlSi3O8)<strong>in</strong> m<strong>in</strong>or amount.<br />
Most <strong>of</strong> them were amorf and it was signed by the<br />
present <strong>of</strong> hump at 2θ 20° up to 30°. Amorf phase<br />
<strong>in</strong> fly ash showed reactivity <strong>of</strong> silica and alum<strong>in</strong>a <strong>in</strong><br />
fly ah, because only amorf phase could dissolve <strong>in</strong><br />
high alkali solution (Duxson et al, 2007).<br />
Table 3 <strong>The</strong> Composition <strong>of</strong> Fly Ash<br />
Oxide % Mass Oxide<br />
SiO2 31,50<br />
Al2O3 12,40<br />
CaO 21,40<br />
Fe2O3 22,50<br />
K2O 0,75<br />
MgO 7,87<br />
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<strong>in</strong>tensity<br />
200<br />
150<br />
100<br />
50<br />
0<br />
Na2O 0,27<br />
P2O5 0,12<br />
SO3 1,06<br />
TiO2 0,76<br />
MnO 0,27<br />
BaO 0,24<br />
SrO 0,09<br />
LOI 0,49<br />
Q<br />
Q<br />
M<br />
A<br />
A<br />
Q Q Q Q<br />
0 10 20 30 40 50 60 70 80<br />
M<br />
2 tetha<br />
Figure 1 X-Ray Diffraction Spectra <strong>of</strong> Fly Ash<br />
Sett<strong>in</strong>g Time and Strength Development<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
Figure 2 F<strong>in</strong>al Sett<strong>in</strong>g Time <strong>of</strong> SiO2/Al2O3 Mol<br />
Ratios<br />
<strong>The</strong> mol ratios <strong>of</strong> SiO2/Al2O3 <strong>in</strong>crease as the<br />
addition <strong>of</strong> Al 3+ species from Al(OH)3 decrease<br />
from a sample to another (Table 1). Figure 2 shows<br />
that the greater SiO2/Al2O3 mol ratios, the shorter<br />
the sett<strong>in</strong>g time. This behaviour could be expla<strong>in</strong>ed<br />
by the role <strong>of</strong> alum<strong>in</strong>ium hydroxide. <strong>The</strong> Al(OH)3<br />
additions to the system <strong>of</strong> the geopolymerisation<br />
process would cause the sett<strong>in</strong>g time <strong>of</strong> geopolymer<br />
was stretched from a sample to another. Further<br />
explanation could arise from a fact that <strong>in</strong> this<br />
composition the NaOH molarities <strong>in</strong>creased with<br />
<strong>in</strong>creas<strong>in</strong>g SiO2/Al2O3 mol ratios and that <strong>of</strong> the fly<br />
ash fraction did, too. Both NaOH molarities and the<br />
solid fraction had been reported to have significant<br />
effects to sett<strong>in</strong>g time (Kamhangrittirong et al,<br />
2006) due to the need <strong>of</strong> water to reach the same<br />
consistency was different. <strong>The</strong> greater SiO2/Al2O3<br />
mol ratios, the less needed water and this mean the<br />
greater NaOH molarity.<br />
In the strong alkal<strong>in</strong>e solution with high pH where<br />
NaOH molarity is high, the formation <strong>of</strong> alum<strong>in</strong>ates<br />
Al(OH)4 – is preferred to have [Al(OH)3(H2O)] 0<br />
form and [SiO2(OH)2] 2- is preferred to have<br />
[SiO(OH)3] - form (Weng, 2005) follow<strong>in</strong>g the<br />
equations below :<br />
Al(OH) 3 + OH – → Al(OH) 4 – ........................ (4.1)<br />
Sett<strong>in</strong>g Time by Vicat Needle Apparatus Al(OH)3 + OH – + H 2O → [Al(OH) 3(H 2O)] 0 (4.2)<br />
Geopolimer paste sett<strong>in</strong>g time is def<strong>in</strong>ed as time<br />
needed for transport, plac<strong>in</strong>g and compaction<br />
process (Teixeira-P<strong>in</strong>to, 2002). Terms transport<br />
and plac<strong>in</strong>g describe the transportation process <strong>of</strong><br />
dissolved species (Si and Al) from particle surface<br />
<strong>of</strong> fly ash <strong>in</strong>to <strong>in</strong>terparticle spaces, while the term<br />
compaction describes the polycondensation process<br />
<strong>of</strong> the the species to form alum<strong>in</strong>osilicate three<br />
dimensional structure.<br />
Determ<strong>in</strong>ation <strong>of</strong> geopolymer paste sett<strong>in</strong>g time by<br />
Vicat Needle Apparatus presented <strong>in</strong> Figure 2<br />
below :<br />
F<strong>in</strong>al Sett<strong>in</strong>g Time (m<strong>in</strong>utes)<br />
200<br />
180<br />
160<br />
140<br />
120<br />
100<br />
80<br />
60<br />
40<br />
20<br />
F<strong>in</strong>al Sett<strong>in</strong>g Time <strong>of</strong> SiO 2 /Al 2 O 3 Mol Ratios<br />
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5<br />
SiO /Al O Moles Ratio<br />
2 2 3<br />
Mol Variation <strong>of</strong> Al 2 O 3 at Constant SiO 2<br />
Mol Variation <strong>of</strong> SiO 2 at Constant Al 2 O 3<br />
SiO 2 + OH - → [SiO 2(H 2O)] 2– ....................... (4.3)<br />
SiO2 + OH – + H 2O → [SiO(OH) 3] – ............. (4.4)<br />
It could be understood that <strong>in</strong> very high alkal<strong>in</strong>e<br />
condition, Al(OH)4 – and [SiO2(H2O)] 2– play more<br />
important role than [Al(OH)3(H2O)] 0 and<br />
[SiO(OH)3] – so that the policondensation reactions<br />
<strong>of</strong> the geopolymerisation process was also quicker<br />
that that <strong>of</strong> the low alkal<strong>in</strong>e condition. <strong>The</strong> greater<br />
addition <strong>of</strong> Al(OH)3, the lower SiO2/Al2O3 mol<br />
ratios, the more [Al(OH)3(H2O)] 0 available, the<br />
more difficult polycondensation reaction to happen,<br />
and so the longer the sett<strong>in</strong>g time.<br />
Compressive Strength by Universal Test<strong>in</strong>g<br />
Mach<strong>in</strong>e<br />
To study strength development <strong>of</strong> SiO2/Al2O3 mol<br />
ratios, measurements <strong>of</strong> compressive sterngth were<br />
carried out at different age, 1 day for <strong>in</strong>itial strength<br />
and 28 days for f<strong>in</strong>al strength. Compressive<br />
strength development <strong>of</strong> geopolymer with variation<br />
<strong>of</strong> SiO2/Al2O3 mol ratios is presented <strong>in</strong> Table 4.<br />
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January 24, 2009<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
Table 4 Compressive Strength Development <strong>of</strong> Geopolymer with Variation <strong>of</strong> SiO2/Al2O3 Mol Ratios<br />
Al2O3 Variation SiO2 Variation Strength Increase<br />
SiO2/Al2O3<br />
Mol Ratios<br />
Initial<br />
Strength<br />
(MPa)<br />
F<strong>in</strong>al<br />
Strength<br />
(MPa)<br />
Initial<br />
Strength<br />
(MPa)<br />
F<strong>in</strong>al<br />
Strength<br />
(MPa)<br />
Al2O3<br />
Variation<br />
SiO2<br />
Variation<br />
0.5 0.60 1.51 - - 2.50 -<br />
1.0 30.92 52.04 - - 1.68 -<br />
1.5 31.87 64.20 0.66 0.85 2.01 1.29<br />
2.0 35.64 66.75 1.51 11.13 1.87 7.38<br />
2.5 39.41 78.06 2.04 21.13 1.98 10.36<br />
3.0 58.92 91.07 11.32 31.70 1.55 2.80<br />
3.5 48.08 85.79 13.76 34.90 1.78 2.54<br />
4.0 40.73 68.08 27.72 44.69 1.67 1.61<br />
4.5 43.94 56.71 52.04 54.30 1.29 1.04<br />
5.0 54.49 74.67 47.18 70.90 1.37 1.50<br />
<strong>The</strong> Average <strong>of</strong> Strength Increase 1.77 3.56<br />
Compressive Strength (MPa)<br />
100.00<br />
90.00<br />
80.00<br />
70.00<br />
60.00<br />
50.00<br />
40.00<br />
30.00<br />
20.00<br />
Compressive Strength <strong>of</strong> SiO2/Al2O3 Mol Ratios<br />
10.00<br />
0.00<br />
0.00 1.00 2.00 3.00 4.00 5.00 6.00<br />
SiO2/Al2O3 Mol Ratios<br />
Initial Strength Initial <strong>of</strong> Al2O3 Strength Variation on Al2O3 Variation FF<strong>in</strong>al <strong>in</strong>al Strength on <strong>of</strong> Al2O3 Al2O3 Variatio Variationn<br />
Initial StrengthInitial <strong>of</strong> SiO Strength on SiO2 Variation F<strong>in</strong>al Strength on <strong>of</strong> SiO2 Variation<br />
2 Variation<br />
Variation<br />
Figure 3 Compressive Strength Development <strong>of</strong> Geopolymer with Variation <strong>of</strong> SiO2/Al2O3 Mol Ratios<br />
In the variation <strong>of</strong> Al2O3 moles at constant SiO2,<br />
there were similar trends <strong>in</strong> both <strong>in</strong>itial and f<strong>in</strong>al<br />
compressive strength. Figure 3 exhibited that the<br />
greater SiO2/Al2O3 mol ratios, the greater<br />
compressive strength and the optimum value was<br />
reached at SiO2/Al2O3 = 3.0, i.e., 58.92 Mpa and<br />
91.07 MPa for 1 and 28 days, respectively. <strong>The</strong><br />
compressive strength decreased at SiO2/Al2O3 = 3.5<br />
and it decreased with <strong>in</strong>creas<strong>in</strong>g SiO2/Al2O3 mol<br />
ratios. <strong>The</strong> average f<strong>in</strong>al strength <strong>in</strong>crease was 1.77<br />
times more than the <strong>in</strong>itial strength. <strong>The</strong>se<br />
important data could be correlated with the sett<strong>in</strong>g<br />
time data previously presented <strong>in</strong> Fig.2. Sett<strong>in</strong>g<br />
time at SiO2/Al2O3 ≥ 3 was low and it decreased<br />
with <strong>in</strong>creas<strong>in</strong>g SiO2/Al2O3 mol ratios. Sett<strong>in</strong>g time<br />
at SiO2/Al2O3 < 3 were <strong>in</strong>creased significantly with<br />
decreas<strong>in</strong>g SiO2/Al2O3 mol ratios.<br />
In the variation <strong>of</strong> SiO2 moles at constant Al2O3, the<br />
trend <strong>in</strong> both <strong>in</strong>itial and f<strong>in</strong>al compressive strengths<br />
was different. <strong>The</strong> <strong>in</strong>itial stength <strong>in</strong>creased with<br />
<strong>in</strong>creas<strong>in</strong>g SiO2/Al2O3 mol ratios, and reached<br />
maximum value at SiO2/Al2O3 = 4.5, i.e., 52.04<br />
MPa, while f<strong>in</strong>al strength reached maximum valua<br />
at SiO2/Al2O3 = 5.0, i.e., 70.90 MPa. <strong>The</strong> average<br />
f<strong>in</strong>al strength <strong>in</strong>crease was 3.56 times more than the<br />
<strong>in</strong>itial. <strong>The</strong> addition <strong>of</strong> SiO2 moles clearly<br />
<strong>in</strong>fluences the development <strong>of</strong> the compressive<br />
strength.<br />
<strong>The</strong> average <strong>in</strong>creas<strong>in</strong>g f<strong>in</strong>al strength on SiO2<br />
variation was greater than that on Al2O3 variation.<br />
One then could concluded that the f<strong>in</strong>al strength<br />
development was <strong>in</strong>fluenced ma<strong>in</strong>ly by SiO2 mol<br />
addition. However, all <strong>of</strong> strengths <strong>in</strong> Al2O3<br />
variation was greater than all <strong>of</strong> strengths <strong>in</strong> SiO2<br />
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variation. It could be expla<strong>in</strong>ed that SiO2/Na2O<br />
mol ratio <strong>in</strong> Al2O3 variation was greater than <strong>in</strong><br />
SiO2 variation. Na2O species could reduce the<br />
strength <strong>of</strong> geopolymer because it would form<br />
Na2CO3 if it reacted with CO2 <strong>in</strong> the air. Density <strong>of</strong><br />
Na2CO3 was also low also and could reduce the<br />
strength <strong>of</strong> geopolymer.<br />
Phase Development by XRD<br />
<strong>in</strong>tensity<br />
0 10 20 30 40 50 60 70 80<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
X-Ray Diffraction spectroscopy was used to<br />
determ<strong>in</strong>e the phase m<strong>in</strong>eralogy <strong>of</strong> geopolymer<br />
with variation <strong>of</strong> SiO2/Al2O3 moles. It was<br />
conducted on geopolymer sample aged <strong>of</strong> 28 days<br />
to ensure that the geopolymerisation process was<br />
stable.<br />
For the variation <strong>of</strong> Al2O3 moles, the spectra is<br />
presented <strong>in</strong> Figure 4 below :<br />
MaMM<br />
Q<br />
MaM<br />
M<br />
Q<br />
G<br />
G<br />
Q<br />
M M M<br />
Q<br />
M MM<br />
GK<br />
Q G QQ<br />
G<br />
G<br />
G<br />
K G<br />
G G G<br />
M Q<br />
G<br />
Q<br />
G Q<br />
Q<br />
Q<br />
Q Q<br />
Q<br />
G<br />
Q<br />
Q<br />
Q<br />
Q<br />
Q<br />
Q<br />
SiO /Al O =5.06<br />
2 2 3<br />
Q<br />
G<br />
G<br />
SiO /Al O =5.0<br />
2 2 3<br />
Q Q<br />
Q Q Q<br />
SiO /Al O =3.0<br />
2 2 3<br />
Q Q<br />
Q<br />
SiO /Al O =2.0<br />
2 2 3<br />
G<br />
G<br />
G<br />
Q<br />
G Q Q Q<br />
SiO /Al O =0.5<br />
2 2 3<br />
2tetha<br />
Figure 4 X-Ray Diffraction Spectra <strong>of</strong> Geopolymer with Variation <strong>of</strong> Al2O3 Moles<br />
Q=quartz (SiO2), M=mullite (3Al2O3.2SiO2), G=gibbsite (Al(OH)3),<br />
Ma=magnetite (FeFe2O4), K=kaol<strong>in</strong>ite (Al2Si2O5(OH)4)<br />
<strong>The</strong> formation <strong>of</strong> geopolymer was signalled by the<br />
shift <strong>of</strong> 2θ=20-30° <strong>in</strong> fly ash <strong>in</strong>to 2θ=25-35° <strong>in</strong><br />
geopolymer. From spectra <strong>in</strong> Figure 4 it could be<br />
seen that at low SiO2/Al2O3 mol ratio, there was<br />
more crystal<strong>in</strong>e phase than at high SiO2/Al2O3 mol<br />
ratio. It was very clear that at SiO2/Al2O3 = 0.5,<br />
most <strong>of</strong> all phase were crystal<strong>in</strong>e with the ma<strong>in</strong><br />
m<strong>in</strong>erals are gybbsite and the m<strong>in</strong>or m<strong>in</strong>erals are<br />
quartz. It should be noted that SiO2/Al2O3 = 0.5 was<br />
the larges <strong>of</strong> Al(OH)3 addition. <strong>The</strong> phase <strong>of</strong><br />
gibbsite then decreased with <strong>in</strong>creas<strong>in</strong>g SiO2/Al2O3<br />
mol ratio because the addition <strong>of</strong> Al2O3 mol was<br />
also decreased. On the other hand, quartz phase<br />
<strong>in</strong>creased with <strong>in</strong>creas<strong>in</strong>g SiO2/Al2O3 mol ratio.<br />
Some m<strong>in</strong>or m<strong>in</strong>erals appeared because <strong>of</strong> the<br />
heterogenousity <strong>of</strong> fly ash component such as<br />
magnetite and kaol<strong>in</strong>ite while the major m<strong>in</strong>erals<br />
such as quartz and mullite came from both alum<strong>in</strong>a<br />
and silika species. All spectra <strong>in</strong> Figure 4 showed<br />
that the most homogenous phase was found at<br />
SiO2/Al2O3=3.0 because it only conta<strong>in</strong>ed quartz<br />
and mullite. This data could expla<strong>in</strong> the sample<br />
with SiO2/Al2O3=3.0 had the highest strength.<br />
When a materials conta<strong>in</strong> more amorphous phase,<br />
its strength would have a higher strength. However,<br />
SiO2/Al2O3=0.5 samples had the lowest value <strong>in</strong><br />
strength because it conta<strong>in</strong> very crystal<strong>in</strong>e phase.<br />
Amorphous phase had more rigid structure than<br />
crystal<strong>in</strong>e phase which had more brittle structure.<br />
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<strong>in</strong>tensity<br />
S<br />
Q<br />
Q<br />
Q<br />
MaMM<br />
Q<br />
MaM<br />
M<br />
Q<br />
Q<br />
S<br />
S<br />
Q Q G MM<br />
Q<br />
Q G<br />
Ma<br />
Q Q<br />
M<br />
S Ma<br />
G<br />
Q Q<br />
Q<br />
Q<br />
M M<br />
Q<br />
Q<br />
Q G Q G<br />
Q QG<br />
0 10 20 30 40 50 60 70 80<br />
2tetha<br />
Q<br />
Q Q<br />
K Q<br />
SiO /Al O =5.06<br />
2 2 3<br />
Q<br />
Q<br />
Q<br />
Q<br />
Q<br />
Q<br />
K<br />
Q<br />
KQ<br />
K<br />
Q<br />
Q G G<br />
Q<br />
Q<br />
Q<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
SiO 2 /Al 2 O 3 =5.0<br />
SiO 2 /Al 2 O 3 =3.5<br />
SiO 2 /Al 2 O 3 =2.5<br />
Q<br />
SiO /Al O =1.5<br />
2 2 3<br />
Figure 5 X-Ray Diffraction Spectra <strong>of</strong> Geopolymer with Variation <strong>of</strong> SiO2 Moles<br />
Q=quartz (SiO2), M=mullite (3Al2O3.2SiO2), G=gibbsite (Al(OH)3),<br />
Ma=magnetite (FeFe2O4), K=kaol<strong>in</strong>ite (Al2Si2O5(OH)4),<br />
S= sodalite (Al6Na8(SiO4).6Cl2)<br />
From spectra <strong>in</strong> Figure 5 shows the phase<br />
development <strong>of</strong> SiO2 variation. It can be seen that<br />
the m<strong>in</strong>erals phase were more heterogenous than<br />
the samples com<strong>in</strong>g from Al2O3 variation. <strong>The</strong><br />
greater SiO2/Al2O3 mol ratios, the more<br />
homogenous and more amorf its m<strong>in</strong>eral. Some<br />
m<strong>in</strong>or m<strong>in</strong>erals appeared because <strong>of</strong> the<br />
heterogenous <strong>of</strong> fly ash component such as<br />
magnetite and kaol<strong>in</strong>ite while the major m<strong>in</strong>erals<br />
such as quartz and mullite came from both alum<strong>in</strong>a<br />
and silika species. Small zeolite phase such as<br />
sodalite appeared <strong>in</strong> low SiO2/Al2O3 mol ratios, that<br />
were SiO2/Al2O3=1.5; 2.5 and 3.5. From all spectra<br />
<strong>in</strong> Fig. 5, it could be seen that SiO2/Al2O3 = 5.0 was<br />
the most homogenous phase so it supported that<br />
f<strong>in</strong>al strength at SiO2/Al2O3 = 5.0 was the highest.<br />
SiO2/Al2O3 = 1.5 had heterogenous phase with the<br />
greatest gibbsite phase lead<strong>in</strong>g to the lowest f<strong>in</strong>al<br />
strength value.<br />
Chemical Bond Development by FTIR<br />
FTIR spectroscopy was used to <strong>in</strong>vestigate the<br />
chemical bond <strong>in</strong> geopolymer us<strong>in</strong>g the variation <strong>of</strong><br />
SiO2/Al2O3 mol ratios. This study is based on the<br />
vibration <strong>of</strong> molecules as a result <strong>of</strong> its <strong>in</strong>teraction<br />
with the <strong>in</strong>frared waves. <strong>The</strong> change <strong>of</strong> resulted<br />
vibration spectra was <strong>in</strong>vestigated.<br />
<strong>The</strong> ma<strong>in</strong> characteristic <strong>of</strong> vibration spectra<br />
appeared as a sign that Si-O-Al cha<strong>in</strong> <strong>in</strong><br />
geopolymer has been formed. Vibration spectra at<br />
wave number 1090-990 cm -1 signed asymetric<br />
stretch<strong>in</strong>g vibration <strong>of</strong> Si-O-Al or Si-O-Si while<br />
vibration at 750-550 cm -1 signed symetric<br />
stretch<strong>in</strong>g vibration <strong>of</strong> Si-O-Al or Si-O-Si.<br />
Vibration at 470-450 cm -1 signed the bend<strong>in</strong>g<br />
vibration <strong>of</strong> Si-O-Al or Si-O-Si and vibration at<br />
about 800cm -1 signed AlO4 vibration (Bakharev,<br />
2005).<br />
FTIR spectra <strong>of</strong> geopolymer with variation <strong>of</strong><br />
Al2O3 moles and variation SiO2 moles were<br />
presented at Figure 6 and Figure 7 below. <strong>The</strong><br />
<strong>in</strong>vestigation was conducted by compar<strong>in</strong>g each <strong>of</strong><br />
the spectra. It shows that the greater SiO2/Al2O3<br />
mol ratios, the higher its <strong>in</strong>tensity. Increas<strong>in</strong>g<br />
<strong>in</strong>tensity meant <strong>in</strong>creas<strong>in</strong>g the cha<strong>in</strong> length <strong>of</strong> Si-O-<br />
Al or Si-O-Si and it signed that there were more<br />
formation <strong>of</strong> gel alum<strong>in</strong>osilicate <strong>in</strong><br />
geopolimerisation. It also showed that the greater<br />
SiO2/Al2O3 mol ratios, the greater the wave<br />
number. Increas<strong>in</strong>g wave number meant <strong>in</strong>creas<strong>in</strong>g<br />
vibration energy, and it signed that the chemical<br />
bond <strong>of</strong> Si-O-Al or Si-O-Si got stronger. <strong>The</strong><br />
<strong>in</strong>crease <strong>of</strong> SiO2/Al2O3 mol ratios lead to the<br />
decrease <strong>of</strong> vibration and <strong>in</strong>tensity <strong>in</strong> wave number<br />
<strong>of</strong> 3400 cm -1 . It signed the loos<strong>in</strong>g <strong>of</strong> water as a<br />
result <strong>of</strong> polycondensation process <strong>in</strong> geopolymer.<br />
In this cases, H-O-H bond gett<strong>in</strong>g weak.<br />
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%T<br />
3448.72<br />
3448.72<br />
3448.72<br />
3456.44<br />
3456.44<br />
1010.70<br />
4500 4000 3500 3000 2500 2000 1500 1000 500 0<br />
Wave Number (cm -1 )<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
Proceed<strong>in</strong>g Book 507<br />
972.12<br />
964.41<br />
956.69<br />
964.41<br />
SiO 2 /Al 2 O 3 =5.06<br />
SiO 2 /Al 2 O 3 =5.0<br />
SiO 2 /Al 2 O 3 =3.0<br />
SiO 2 /Al 2 O 3 =2.0<br />
SiO 2 /Al 2 O 3 =0.5<br />
Figure 6 FTIR Spectra <strong>of</strong> Geopolymer with Variation <strong>of</strong> Al2O3 Moles<br />
%T<br />
Microstructure Development by SEM<br />
3448.72<br />
3448.72<br />
3433.29<br />
3448.72<br />
3448.72<br />
972.12<br />
462.92<br />
972.12 455.20<br />
972.12 447.49<br />
SiO /Al O =2.5<br />
2 2 3<br />
979.84<br />
455.20<br />
SiO /Al O =1.5<br />
2 2 3<br />
972.12<br />
439.77<br />
4000 3000 2000 1000 0<br />
Wave Number (cm -1 )<br />
SiO 2 /Al 2 O 3 =5.06<br />
SiO 2 /Al 2 O 3 =5.0<br />
SiO 2 /Al 2 O 3 =3.5<br />
Figure 7 FTIR Spectra <strong>of</strong> Geopolymer with Variation <strong>of</strong> SiO2 moles<br />
Geopolymer morphology <strong>in</strong> the micro scale has<br />
been <strong>in</strong>vestigated by Scann<strong>in</strong>g Electron<br />
Microscopy. SEM images <strong>of</strong> polished samples with<br />
corresposnd<strong>in</strong>g SiO2/Al2O3 mol ratios are presented<br />
<strong>in</strong> Figure 8, 9 and 10. A significant change <strong>in</strong><br />
microstructure, especially homogeneity,<br />
compactness, pores structure and some microcracks<br />
were associated with chang<strong>in</strong>g SiO2/Al2O3 mol<br />
ratios.<br />
As shown <strong>in</strong> Fig.8, microstucture <strong>of</strong> SiO2/Al2O3 =<br />
5.06 which was designed without any addition <strong>of</strong><br />
Al(OH)3. It shows a homogeneity and compactness<br />
<strong>of</strong> geopolymer matrix, but some microcracks and<br />
pores caused its f<strong>in</strong>al strength was lower than that<br />
<strong>of</strong> SiO2/Al2O3 = 5.06 presented <strong>in</strong> Figure 8.(iii).<br />
<strong>The</strong> latter figure shows more homogenous, more<br />
compact, less porous and less fracture surfaces.
<strong>The</strong> First International Sem<strong>in</strong>ar on Science and Technology<br />
January 24, 2009<br />
SEM images <strong>of</strong> geopolymer with variation <strong>of</strong><br />
Al2O3 moles are presented <strong>in</strong> Fig. 9. Microstucture<br />
<strong>of</strong> SiO2/Al2O3 = 0.5 shows gra<strong>in</strong> structures, which<br />
<strong>in</strong>tergra<strong>in</strong>s were not cemented. This exhibited less<br />
compact structure and made it has the lowest f<strong>in</strong>al<br />
strength. Microstucture <strong>of</strong> SiO2/Al2O3 = 2.0 was<br />
more compact, with gra<strong>in</strong> structure began to be<br />
cemented, so it had f<strong>in</strong>al strength greater than<br />
SiO2/Al2O3 = 0.5. Microstucture <strong>of</strong> SiO2/Al2O3 =<br />
3.0 was the most wanted structure because its<br />
c<br />
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Proceed<strong>in</strong>g Book 508<br />
a<br />
Figure 8 SEM Micrograph <strong>of</strong> Geopolymer with SiO2/Al2O3 = 5.06<br />
a. geopolymer matrix, b. microcrack and fracture surface,<br />
c. pores<br />
(i) SiO2/Al2O3 =0.5 (ii) SiO2/Al2O3 = 2.0<br />
c<br />
a<br />
d<br />
b<br />
matrix had homogenous and a good compactness,<br />
although there were some residual (unreacted) fly<br />
ash and some pores lead<strong>in</strong>g to the highest f<strong>in</strong>al<br />
strength. Microstucture <strong>of</strong> SiO2/Al2O3 = 5.0<br />
exhibited more unreacted fly ash and residual<br />
matter, so its f<strong>in</strong>al strength decreased. Improvement<br />
<strong>in</strong> microstructural homogheneity is conventionally<br />
a strong <strong>in</strong>dication <strong>of</strong> higher strength (De Silva,<br />
2007).<br />
(iii) SiO2/Al2O3 = 3.0 (iv) SiO2/Al2O3 = 5.0<br />
Figure 9 SEM Micrograph <strong>of</strong> Geopolymer with Variation <strong>of</strong> Al2O3 Moles (a. gra<strong>in</strong> structure,<br />
b. Cemented gra<strong>in</strong> structure, c. Dense matrix geopolymer, d. Pore, e. Unreacted fly ash)<br />
b<br />
e
<strong>The</strong> First International Sem<strong>in</strong>ar on Science and Technology<br />
January 24, 2009<br />
SEM images <strong>of</strong> geopolymer with variation <strong>of</strong> SiO2<br />
moles are presented <strong>in</strong> Fig. 10. Microstucture <strong>of</strong><br />
SiO2/Al2O3 = 1.5 showed needle structure with<br />
some gra<strong>in</strong>s. This structure was caused by the ratio<br />
<strong>of</strong> SiO2/Na2O which was very lower than the other<br />
composition. <strong>The</strong>re were no geopolymer matrix so<br />
it exhibited the lowest strength. Microstucture <strong>of</strong><br />
SiO2/Al2O3 = 2.5 shows more cemented gra<strong>in</strong><br />
structure with unreacted fly ash, so it caused more<br />
Conclusions<br />
a<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
strength than that <strong>of</strong> SiO2/Al2O3 = 1.5.<br />
Microstucture <strong>of</strong> SiO2/Al2O3 = 3.5 showed<br />
geopolymer matrix with some unreacted reactants<br />
and pores so it reached high enough strength. While<br />
microstucture <strong>of</strong> SiO2/Al2O3 = 5.0 showed dense<br />
geopolymer matrix with some cracks and unreacted<br />
fly ash. This matrix <strong>of</strong> SiO2/Al2O3 = 5.0 was so<br />
compact that it had the highest strength <strong>in</strong> variation<br />
<strong>of</strong> SiO2.<br />
c<br />
b d<br />
(i) SiO2/Al2O3 = 1.5 (ii) SiO2/Al2O3 = 2.5<br />
f<br />
d<br />
e g d<br />
(iii) SiO2/Al2O3 = 3.5 (iv) SiO2/Al2O3 = 5.0<br />
Figure 10 SEM Micrograph <strong>of</strong> Geopolymer with Variation <strong>of</strong> SiO2 Moles<br />
a. gra<strong>in</strong> structure, b. needle structure, c. more cemented gra<strong>in</strong><br />
structure, d. unreacted fly ash, e. geopolymer matrix,<br />
f. Pores, g. cracks<br />
<strong>Addition</strong> <strong>of</strong> alum<strong>in</strong>ate species at constant silicate<br />
and decrease <strong>of</strong> NaOH molarity made sett<strong>in</strong>g time<br />
<strong>in</strong>crease as there were more Al(OH)3(H2O)<br />
complex species prohibited polycondensation<br />
reaction. <strong>The</strong> optimum compressive strength was<br />
acieved at mol ratio <strong>of</strong> SiO2/Al2O3=3.0 for variation<br />
<strong>of</strong> Al2O3 and SiO2/Al2O3=5.0 for variation <strong>of</strong> SiO2.<br />
<strong>The</strong> total moles <strong>of</strong> the start<strong>in</strong>g materials <strong>of</strong> both<br />
variation were similar, but they were very different<br />
<strong>in</strong> compressive strength because <strong>of</strong> the effect <strong>of</strong><br />
differences <strong>in</strong> SiO2/Na2O ratio. <strong>The</strong> phase<br />
e<br />
development shows that the greater SiO2/Al2O3 mol<br />
ratio, the greater formation <strong>of</strong> amorphous<br />
homogenous phase. It lead to reach optimum<br />
SiO2/Al2O3 mol ratio. FTIR study shows that the<br />
greater SiO2/Al2O3 mol ratio, the greater <strong>in</strong>tensity<br />
wave number <strong>of</strong> vibration mean<strong>in</strong>g <strong>in</strong>creas<strong>in</strong>g <strong>of</strong><br />
the cha<strong>in</strong> length Si-O-Al or Si-O-Si and <strong>in</strong>creas<strong>in</strong>g<br />
vibration energy. It revealed that there were more<br />
formation <strong>of</strong> gel alum<strong>in</strong>osilicate <strong>in</strong><br />
geopolimerisation and that the chemical bond <strong>of</strong> Si-<br />
O-Al or Si-O-Si gett<strong>in</strong>g strong at optimum<br />
SiO2/Al2O3 mol ratio. Gra<strong>in</strong> structure appeared at<br />
low SiO2/Al2O3 and it made lower strength, while<br />
homogenous geopolymer matrix appeared at<br />
Proceed<strong>in</strong>g Book 509
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January 24, 2009<br />
optimum SiO2/Al2O3 mol ratio and it lead to higher<br />
strength. Unreacted fly ash and residual reactant<br />
appeared at high SiO2/Al2O3 mol ratio caused a<br />
lower strength geopolymer. In the SiO2-Al2O3-<br />
Na2O-H2O system, all component are<br />
<strong>in</strong>terdependent relationship, so <strong>in</strong> this research there<br />
was significant effect <strong>of</strong> Na2O and H2O, too.<br />
References<br />
Aly, Z., Vance, E. R., Perera, D. S., Hanna, J. V.,<br />
Griffith, C. S., Davis, J., and Durce, D.,<br />
(2008), “Aqueous Leachability <strong>of</strong><br />
Metakaol<strong>in</strong>-Based Geopolimers with Molar<br />
Ratios <strong>of</strong> Si/Al = 1.5-4”, Journal <strong>of</strong> Nuclear<br />
Materials, Vol. 378, page 172-179.<br />
Bakharev, T., (2005a), “Gepolimeric Materials<br />
Prepared Us<strong>in</strong>g Class F Fly Ash and<br />
Elevated Temperature Cur<strong>in</strong>g”, Cement and<br />
Concrete Research, Vol. 35, page 1224-<br />
1232.<br />
Bakharev, T., (2005b), “Durability <strong>of</strong> Geopolymer<br />
Materials <strong>in</strong> Sodium and Magnesium Sulfate<br />
Solutions”, Cement and Concrete Research,<br />
Vol. 35, page 1233-1246.<br />
Ch<strong>in</strong>daprasirt, P., Chareerat, T., and Sirivivatnanon,<br />
V., (2007), “Workability and Strength <strong>of</strong><br />
Coarse High Calsium Fly Ash Geopolymer”,<br />
Cement and Concrete Composites, Vol. 29,<br />
page 224-229.<br />
Davidovits, J., (1991), “Geopolymer : Inorganic<br />
Polymeric New Materials”, Journal <strong>of</strong><br />
<strong>The</strong>rmal Analysis, Vol. 3, page 1633-1656.<br />
Davidovits, J., (1994a), “Geopolimers : Man-Made<br />
Rock Geosynthesis and the Result<strong>in</strong>g<br />
Development <strong>of</strong> Very Early High Strength<br />
Cement”, Journal <strong>of</strong> Materials Education,<br />
Vol. 16 (2&3), page 91-139.<br />
Davidovits, J., (1994b), “Properties <strong>of</strong> Geopolymer<br />
Cements”, Proceed<strong>in</strong>g First International<br />
Conference on Alkal<strong>in</strong>e Cements and<br />
Concrete, Scientific Research Institute on<br />
B<strong>in</strong>ders and Materials, Kiev State Technical<br />
University, Kiev, Ukra<strong>in</strong>e, page 131-149.<br />
Davidovits, J., (1994c), “Recent Progress <strong>in</strong><br />
Concrete for Nuclear Waste and Uranium<br />
Waste Conta<strong>in</strong>ment”, Journal <strong>of</strong> Concrete<br />
International, Vol. 16, No. 12, page 53-58.<br />
Davidovits, J., and Davidovics, M., (1991),<br />
“Geopolymer : Ultra-High Temperature<br />
Tool<strong>in</strong>g Material for the Manufacture <strong>of</strong><br />
Advanced Composites”, Geopolymer<br />
Tool<strong>in</strong>g Material, Vol. 2, No. 36, page 1939-<br />
1949.<br />
De Silva, P., Sagoe-Crenstil, K., and<br />
Sirivivatnanon, V., (2007), “K<strong>in</strong>etics <strong>of</strong><br />
Geopolymerization : Role <strong>of</strong> Al2O3 and<br />
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SiO2”, Cement and Concrete Research, Vol.<br />
37, page 512-518.<br />
Duxson, P., Mallicoat, S. W., Lukey, G. C., Kriven,<br />
W., M., and van Deventer, J., S. J., (2007),<br />
<strong>The</strong> Effect <strong>of</strong> Alkali and Si/Al Ratio on the<br />
Development <strong>of</strong> Mechanical Properties <strong>of</strong><br />
Metakaol<strong>in</strong>-based Geopolimers”, Colloids<br />
and Surfaces A : Physicochemistry.<br />
Eng<strong>in</strong>eer<strong>in</strong>g. Aspects, Vol. 292, page 8-20.<br />
Duxson, P., Provis, J. l., Mallicoat, S. W., Lukey,<br />
G. C., Kriven, W., M., and van Deventer, J.,<br />
S. J., (2005), ”Understand<strong>in</strong>g the<br />
Relationship between Geopolymer<br />
Composition, Microstructure and<br />
Mechanical Properties”, Colloids and<br />
Surfaces, Vol. 269, page 47-58.<br />
Fansuri, H. (2008b), Personal Communication. 8 th<br />
October 2008.<br />
Fernandez-Jimenez, A., Palomo, A., Sobrados, I.,<br />
and Sanz, J., (2006), “<strong>The</strong> Role Played by<br />
Reactive Alum<strong>in</strong>a Content <strong>in</strong> the Alkal<strong>in</strong>e<br />
Activation <strong>of</strong> Fly Ashes”, Microporous and<br />
Mesoporous Materials, Vol. 91, page111-<br />
119.<br />
Fletcher, R.A., MacKenzie, K. D. J., Nicholson, C.<br />
L., and Shimada, S., (2005), “<strong>The</strong><br />
Composition Range <strong>of</strong> Alum<strong>in</strong>osilicate<br />
Geopolymers”, Journal <strong>of</strong> <strong>The</strong> European<br />
Ceramic Society, Vol. 25, page. . 1471-1477.<br />
Hardjito, D., Wallah, S. E., Sumajouw, M. J.,<br />
Rangan, B. V, (2004), “Factors Infuenc<strong>in</strong>g<br />
<strong>The</strong> Compressive Strength <strong>of</strong> Fly Ash-Based<br />
Geopolymer Concrete”, Dimensi Teknik<br />
Sipil, Vol. 6, No. 2, page 88-93.<br />
Kamhangrittirong, P. and Suwanvitaya, P., (2006),<br />
“<strong>The</strong> Effect <strong>of</strong> Fly Ash Content and Sodium<br />
Hydroxide Molarity on Geopolymer”,<br />
International Conference on Pozzolan,<br />
Concrete and Geopoymer, page 213-218.<br />
Komnitsas, K. and Zaharaki, D., (2007),<br />
“Geopolimerisation : A Review and<br />
Prospects for the M<strong>in</strong>erals Industry“,<br />
M<strong>in</strong>erals Eng<strong>in</strong>eer<strong>in</strong>g, Vol. 20, page 1261-<br />
1277.<br />
Lee, W. K. W. and van Deventer, J. S. J., (2002),<br />
“<strong>The</strong> Effect <strong>of</strong> Ionic Contam<strong>in</strong>ants on the<br />
Early-Age <strong>of</strong> Alkali-Activated Fly Ash<br />
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Mishra, A., Choudhary, D., Ja<strong>in</strong>, N., Kumar, M.,<br />
Sharda, N., and Dutt, D., (2008). “Effect <strong>of</strong><br />
Concentration <strong>of</strong> Alkal<strong>in</strong>e Liquid and Cur<strong>in</strong>g<br />
Time on Strength and Water Absorption <strong>of</strong><br />
Geopolymer Concrete”. Asian Research<br />
Publish<strong>in</strong>g Network (ARPN) Journal <strong>of</strong><br />
Eng<strong>in</strong>eer<strong>in</strong>g and Applied Sciences, Vol. 3,<br />
No. 1, page 14-18.<br />
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January 24, 2009<br />
Palomo, A., Grutzeck, M. W., and Blanco, M. T.,<br />
(1999), “Alkali-Activated Fly Ashes, A<br />
Cement for the Future”, Cement and<br />
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1329.<br />
Phair, J. W., Smith, J. D., and van Deventer, J. S. J.,<br />
(2003), “Characteristics <strong>of</strong> Alum<strong>in</strong>osilcate<br />
Hydrogels Related to Commercial<br />
Geopolymers”, Materials Letters, Vol. 57,<br />
page 4356-4367.<br />
Riza<strong>in</strong>, (2008), Pelarutan Alum<strong>in</strong>ium and Silikon<br />
Berbagai Abu Layang Batubara dari Empat<br />
PLTU Menggunakan Variasi Konsentrasi<br />
NaOH and Temperatur, Tesis, Program<br />
Magister FMIPA Institut Teknologi Sepuluh<br />
Nopember, Surabaya.<br />
Swaddle, T. W., (2001), “Silicate Complexes <strong>of</strong><br />
Alum<strong>in</strong>um(III) <strong>in</strong> Aqueous Systems”,<br />
Coord<strong>in</strong>ation Chemistry Reviews, Vol. 219-<br />
221, page 665-686.<br />
Teixeira-P<strong>in</strong>to, A. Fernandez, P., and Jalali, S.,<br />
(2002), “Geopolymer Manufacture and<br />
Application – Ma<strong>in</strong> Problems when Us<strong>in</strong>g<br />
Concrete Technology”, Proceed<strong>in</strong>g <strong>of</strong><br />
International Conference on Geopolymer,<br />
28-29 October, Melbourne, Australia.<br />
van Deventer, J. S. J., Provis, L. J., and Lukey, G.<br />
C., (2007), “Reaction Mechanisms <strong>in</strong> the<br />
Geopolymeric Conversion <strong>of</strong> Inorganic<br />
Waste to Useful Products”, Journal <strong>of</strong><br />
Hazardous Materials, Vol. A139, page 506-<br />
513.<br />
van Jaarsveld, J. G. S., and van Deventer, J. S. J.,<br />
(1996), “<strong>The</strong> Potential Use <strong>of</strong> Geopolymeric<br />
Materials to Immobilize Toxic Metals : Part<br />
I. <strong>The</strong>ory and Application”, Journal <strong>of</strong><br />
M<strong>in</strong>erals Eng<strong>in</strong>eer<strong>in</strong>g, Vol. 10, No. 7, page<br />
659-669.<br />
van Jaarsveld, J. G. S., van Deventer, J. S. J., and<br />
Lukey, G. C., (2003), “<strong>The</strong> Characterization<br />
<strong>of</strong> Source Materials <strong>in</strong> Fly Ash-Based<br />
Geopolymers”, Materials Letters. Vol. 57,<br />
page 1272-1280.<br />
van Jaarsveld, J.G.S. and van Deventer, J. S. J.,<br />
(1996), <strong>The</strong> Potential Use <strong>of</strong> Geopolimeric<br />
Materials to Immobilize Toxic Metals : Part<br />
I. <strong>The</strong>ory and Applications, M<strong>in</strong>erals<br />
Eng<strong>in</strong>eer<strong>in</strong>g, Vol. 10, No. 7, page 659-669.<br />
Weng, L., Sagoe-Cretsil, K., Brown, T., and Song,<br />
S., (2005), “Effects <strong>of</strong> Alum<strong>in</strong>ates on the<br />
Formation <strong>of</strong> Geopolimers”, Materials<br />
Science and Eng<strong>in</strong>eer<strong>in</strong>g B, Vol. 117, page<br />
163-168.<br />
Xu, H. and van Deventer, J. S. J., (2000), “<strong>The</strong><br />
Geopolymerisation <strong>of</strong> Alum<strong>in</strong>o-silicate<br />
M<strong>in</strong>erals”, International Journal <strong>of</strong> M<strong>in</strong>eral<br />
Process<strong>in</strong>g, Vol. 59, page 247-266.<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
Proceed<strong>in</strong>g Book 511
<strong>The</strong> First International Sem<strong>in</strong>ar on Science and Technology<br />
January 24, 2009<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
Structural Shield<strong>in</strong>g Design for Mobile X-Ray Units <strong>in</strong> Local Public Hospitals<br />
<strong>in</strong> Yogyakarta.<br />
Introduction<br />
Zaenal Abid<strong>in</strong><br />
Sekolah T<strong>in</strong>ggi Teknologi Nuklir-Badan Tenaga Nuklir Nasional<br />
Jln Babarsari. P.O.BOX 6101 YKBB Yogyakarta 55281<br />
Telp : (0274) 48085, 489716; Fax : (0274) 489715<br />
E-mail : zaenala6@gmail.com<br />
Abstract<br />
A research has been conducted on the operation <strong>of</strong> mobile X-ray units <strong>in</strong> three local public hospitals <strong>in</strong><br />
Yogyakarta <strong>in</strong> order to determ<strong>in</strong>e the m<strong>in</strong>imum thickness for safe structural shield<strong>in</strong>g. Data were taken by<br />
operat<strong>in</strong>g each mach<strong>in</strong>e 25 times, respectively, <strong>in</strong> 70 kV and 40 mAs. <strong>The</strong> level <strong>of</strong> radiation exposure was<br />
then measured with the tube positions <strong>of</strong> vertical, axial, horizontal to determ<strong>in</strong>e the safe distance and shield<br />
thickness. <strong>The</strong> result shows that the safe distance for the position beside the tube is 3.08 meters for the<br />
operators and 12.02 meters for others, while for the position beh<strong>in</strong>d the tube, the safe position is 1.41<br />
meters for both. <strong>The</strong> structural shield<strong>in</strong>g needed is 1.5 mm lead (Pb) or 16 cm concrete.<br />
Keywords: X-ray Mobile Unit, tube position, safe distance, structural shield<strong>in</strong>g.<br />
Mobile X-ray systems are moved around hospitals<br />
all the time to perform radiographic photography on<br />
patients who cannot easily get <strong>in</strong>to an X-ray room. In<br />
operat<strong>in</strong>g the mach<strong>in</strong>e, we must be sure that it is safe<br />
for the staffs, personnel or operators <strong>of</strong> the X-ray unit,<br />
patients and other members <strong>of</strong> the public.<br />
International regulations demand that diagnostic<br />
and therapy departments are built to ensure that<br />
radiology and radiotherapy staffs, personnel work<strong>in</strong>g <strong>in</strong><br />
the vic<strong>in</strong>ity <strong>of</strong> a radiation source, patients and members<br />
<strong>of</strong> the public are exposed to the m<strong>in</strong>imum amount <strong>of</strong><br />
radiation [1] .<br />
Local public hospitals <strong>in</strong> Yogyakarta which possess<br />
the facility <strong>of</strong> x-ray mobile units rarely use them <strong>in</strong> the<br />
treatment room (<strong>in</strong> situ) due to the fact that the safe<br />
distance from the radiation sh<strong>in</strong><strong>in</strong>g is not yet known<br />
concern<strong>in</strong>g the radiation exposure [2] . This research will<br />
reveal how much the radiation exposure is, what the<br />
safe distance is and how to design the required<br />
structural shield<strong>in</strong>g.<br />
<strong>The</strong>ory<br />
<strong>The</strong> basic pr<strong>in</strong>ciples <strong>of</strong> external radiation<br />
protection are lengthen<strong>in</strong>g the distance, shorten<strong>in</strong>g the<br />
sh<strong>in</strong><strong>in</strong>g exposure, and us<strong>in</strong>g appropriate radiation<br />
shield. A mobile X-ray mach<strong>in</strong>e is a source <strong>of</strong> external<br />
radiation. <strong>The</strong>refore, for protection from external<br />
radiation, make sure to use shortest time with<br />
the radiation, and farthest possible distance for<br />
radiation, and the necessary thickness <strong>of</strong><br />
radiation shield.<br />
<strong>The</strong> formula <strong>in</strong> calculat<strong>in</strong>g radiation and<br />
distance is a reversed square: [3]<br />
1<br />
Dr = K × 2<br />
r<br />
or Dr . r 2 = K<br />
so Dr 1 . r1 2 = Dr 2 . r2 2 = Dr 3 . r3 2 = K<br />
[1]<br />
where:<br />
K is a constant which depends on the source,<br />
Dr 1 is dose rate at distance r1,<br />
Dr 2 is dose rate at distance r2, and<br />
Dr 3 is dose rate at distance r3.<br />
<strong>The</strong> purpose <strong>of</strong> radiation shield<strong>in</strong>g is to<br />
limit radiation exposures to human be<strong>in</strong>gs (both<br />
workers and the public) to an acceptable level.<br />
Shield<strong>in</strong>g <strong>of</strong> X-ray mach<strong>in</strong>es consists <strong>of</strong> two<br />
k<strong>in</strong>ds: tube hous<strong>in</strong>g shield<strong>in</strong>g and structural<br />
shield<strong>in</strong>g.<br />
X-ray tube hous<strong>in</strong>g shield<strong>in</strong>g <strong>of</strong> energies less<br />
than 500 KV, <strong>in</strong> accordance with NCRP<br />
(National Council on Radiological Protection<br />
and Measurement) shall have the maximum<br />
leakage dose <strong>of</strong> 1 R/hr [1] .<br />
Primary protective barrier is the wall <strong>of</strong><br />
x-ray room designated to face primary rays or<br />
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useful beam and the secondary protective barrier is<br />
<strong>in</strong>tended to shield Leakage radiation from the tube<br />
hous<strong>in</strong>g and scattered radiation from the mach<strong>in</strong>e.<br />
Primary Protective barrier (Barrier aga<strong>in</strong>st Useful<br />
Beam)<br />
<strong>The</strong> attenuation or the number <strong>of</strong> Roentgens per milli<br />
Ampere m<strong>in</strong>utes <strong>in</strong> a week for the useful beam<br />
normalized at one meter, K [4] (see Fig.1)<br />
2<br />
P.(<br />
d pri)<br />
K = R / mA-<br />
m<strong>in</strong> at 1 m [2]<br />
WUT<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
P = permissible dose 0.1 R/week for<br />
Radiation Worker (Controlled Area) or<br />
0.01 R/week for Non Radiation Worker<br />
(Non Controlled Area)<br />
dpri = distance between focus and po<strong>in</strong>t <strong>of</strong><br />
<strong>in</strong>terest<br />
W = work load (mA-m<strong>in</strong>utes)/week<br />
U = Use factor (U=1 for Floor, and U<br />
=0.25 for walls)<br />
T = Occupancy factor<br />
By calculat<strong>in</strong>g the K value, we can determ<strong>in</strong>e<br />
the thickness <strong>of</strong> Primary Protective barrier by<br />
plott<strong>in</strong>g K value to the graph for certa<strong>in</strong> kV <strong>of</strong><br />
Fig.1<br />
Figure 1 Attenuation <strong>in</strong> lead <strong>of</strong> x-rays produced by potentials <strong>of</strong> 50 to 200 kV. [4]<br />
Secondary Protective Barrier (Barrier aga<strong>in</strong>st Leaked<br />
Radiation)<br />
<strong>The</strong> transmission factor B [4] is<br />
2<br />
P.(<br />
dsec)<br />
. 60.<br />
I<br />
B = [3]<br />
W.<br />
T<br />
Where:<br />
P = permissible dose 0.1 R/week for<br />
Radiation Worker (Controlled Area) or<br />
0.01 R/week for non Radiation Worker<br />
(Non Controlled Area)<br />
dsec = distance between focus and po<strong>in</strong>t <strong>of</strong><br />
<strong>in</strong>terest<br />
W = work load (mA-m<strong>in</strong>utes)/week<br />
T = Occupancy factor<br />
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I = milli Ampere<br />
To determ<strong>in</strong>e the thickness <strong>of</strong> secondary protective<br />
barrier aga<strong>in</strong>st leakage radiation transmission factor B<br />
is equal to<br />
n<br />
B = ( 1/<br />
2)<br />
[4]<br />
n = X / HVL<br />
Where:<br />
X = thickness <strong>of</strong> Secondary protective barrier<br />
aga<strong>in</strong>st leakage radiation<br />
HVL = Half Value Layer<br />
Secondary Protective Barrier (Barrier aga<strong>in</strong>st<br />
Scattered Radiation)<br />
<strong>The</strong> attenuation or the number <strong>of</strong> Roentgens per milli-<br />
Ampere m<strong>in</strong>utes <strong>in</strong> a week for the useful beam<br />
normalized at one meter, K (see Fig.1). We take Fig.1<br />
because <strong>of</strong> by assum<strong>in</strong>g that the energy <strong>of</strong> the scattered<br />
radiation when the X-rays are generated at 500kV or<br />
less, is equal to the energy <strong>of</strong> the useful beam [4]<br />
2 2<br />
P.(<br />
dsec)<br />
.( dsca)<br />
. 400<br />
K = [5]<br />
a.<br />
W.<br />
T.<br />
F<br />
P =permissible dose 0.1 R/week for Radiation<br />
Worker (Controlled Area) or 0.01 R/week for<br />
Non Radiation Worker (Non Controlled Area)<br />
dsec =distance between focus and po<strong>in</strong>t <strong>of</strong> <strong>in</strong>terest<br />
dsca = distance between focus and scattered<br />
W =work load (mA-m<strong>in</strong>utes)/week<br />
T =Occupancy factor<br />
F =Area <strong>of</strong> scattered to <strong>in</strong>cident exposure at 1<br />
meter from the scattered<br />
By calculat<strong>in</strong>g K value, we can determ<strong>in</strong>e the<br />
thickness <strong>of</strong> the Secondary Protective barrier aga<strong>in</strong>st<br />
scattered radiation by plott<strong>in</strong>g K value to the graph for<br />
certa<strong>in</strong> KV <strong>of</strong> Fig. 1 above.<br />
If the thickness <strong>of</strong> required barrier for leakage<br />
and scattered radiations is found to be approximately<br />
the same, one HVL should be added to the larger one<br />
to obta<strong>in</strong> the required total secondary barrier thickness.<br />
If the two differ by at least one TVL, the thicker <strong>of</strong> the<br />
two will be adequate.<br />
Select<strong>in</strong>g the material and form used for the<br />
structural radiation shield is based on the number <strong>of</strong><br />
radiation energy exposed to be attenuated, the barrier<br />
function, factors <strong>of</strong> practicality and efficiency <strong>in</strong> usage,<br />
storage, and economical, as well as the rules by<br />
Department <strong>of</strong> Health <strong>in</strong> 1999 [6] . <strong>The</strong> selected material<br />
is lead (Pb) plat <strong>of</strong> 2 mm thick with the U-form [7] .<br />
Materials and Methods<br />
Device and material<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
Survey meter was used <strong>in</strong> measur<strong>in</strong>g the<br />
radiation secondary exposure, roll meter <strong>in</strong><br />
measur<strong>in</strong>g distance, and warn<strong>in</strong>g sign lamps,<br />
film badge (to record the <strong>in</strong>dividual radiation<br />
dose), mobile X-ray mach<strong>in</strong>es (Siemens DSA-7),<br />
and protective lead apron.<br />
Activity<br />
Data were taken by operat<strong>in</strong>g each mach<strong>in</strong>e 25<br />
times <strong>in</strong> three hospitals: Regional Public<br />
Hospital (RPH) Yogyakarta, RPH Sleman, and<br />
RPH Wonosari Gunung Kidul, by measur<strong>in</strong>g<br />
the dose rate at the distances <strong>of</strong> 2.24 m and 1.41<br />
m from tube placed as high as the gonad, us<strong>in</strong>g<br />
the protection procedure taken with exposure at<br />
70kV/40mAs. <strong>The</strong> data were recorded and<br />
calculated us<strong>in</strong>g the formulation expla<strong>in</strong>ed<br />
above. Sh<strong>in</strong><strong>in</strong>g was conducted to the object <strong>of</strong> a<br />
fat body by 70kV and 40mAs. Focus film<br />
distance (FFD) is 1 meter and then pulled aside<br />
2 meters with the farthest assumption distance<br />
<strong>of</strong> patient’s bed, so the distance r1 is 2.24 meters<br />
from the focus<strong>in</strong>g tube, while for the beh<strong>in</strong>d<br />
position used FDD one meter, and distance <strong>of</strong> r1<br />
is 1.41 meter from the focus<strong>in</strong>g tube; such a<br />
distance is assumed as the distance <strong>of</strong> the<br />
worker <strong>in</strong> stand<strong>in</strong>g position.<br />
<strong>The</strong> Calculation<br />
Calculation taken <strong>in</strong>to consideration by us<strong>in</strong>g<br />
the formulations above concern<strong>in</strong>g with the<br />
condition <strong>of</strong>:<br />
Orientation factor (U) [5]<br />
• If the radiation beam is oriented <strong>in</strong><br />
some particular direction for more than<br />
50 per cent <strong>of</strong> the time when the device<br />
is <strong>in</strong> use, then a value <strong>of</strong> U = 1 is used<br />
for specify<strong>in</strong>g the shield<strong>in</strong>g <strong>in</strong> this<br />
direction.<br />
• If the radiation beam is oriented <strong>in</strong><br />
some particular direction for less than<br />
50 per cent <strong>of</strong> the time when the device<br />
is <strong>in</strong> use, then a value <strong>of</strong> 0.25 < U < 1<br />
may be used for specify<strong>in</strong>g the<br />
shield<strong>in</strong>g. However, the orientation<br />
factor must always be no smaller than<br />
the proportion <strong>of</strong> time <strong>in</strong> use for which<br />
the beam is oriented <strong>in</strong> this direction.<br />
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• A value <strong>of</strong> U = 1 is used <strong>in</strong> directions affected<br />
only by leakage and scattered radiations.<br />
Occupancy factor (T)<br />
• A value <strong>of</strong> T = 1 is used <strong>in</strong> work<strong>in</strong>g premises<br />
and, <strong>in</strong> the case <strong>of</strong> medical use <strong>of</strong> radiation,<br />
also <strong>in</strong> wait<strong>in</strong>g rooms and patient rooms.<br />
• A value <strong>of</strong> 0.1 < T < 1 may be used <strong>in</strong> <strong>in</strong>door<br />
or outdoor premises where human be<strong>in</strong>gs do<br />
not rema<strong>in</strong> on a cont<strong>in</strong>ual basis (e.g. WCs,<br />
corridors, storerooms or streets). However, the<br />
occupancy factor shall always be no smaller<br />
than the proportion <strong>of</strong> time dur<strong>in</strong>g which<br />
human be<strong>in</strong>gs occupy the area concerned.<br />
Result and Discussions<br />
In the medical radiography, the technique <strong>of</strong><br />
tak<strong>in</strong>g pictures, i.e. the tube position, is determ<strong>in</strong>ed by<br />
patient condition. <strong>The</strong> position and function <strong>of</strong> the tube<br />
should be as follows:<br />
Table 1. Tube Position and Function [2]<br />
No Position Function<br />
1. Vertical Tak<strong>in</strong>g pictures <strong>of</strong><br />
cranium, cervical, thorax,<br />
abdomen, pelvis, thoracic<br />
vertebrae, lumbosacral<br />
2. Axial<br />
vertebrae, for high and<br />
low extremities.<br />
35 o<br />
Tak<strong>in</strong>g pictures <strong>of</strong> thorax<br />
with the patient’s<br />
position half seated,<br />
abdomen with the<br />
patient’s position half<br />
seated, and cranium with<br />
towne’s position<br />
3. Horizont Tak<strong>in</strong>g pictures <strong>of</strong><br />
al cranium lateral, cervical<br />
lateral, and abdomen<br />
with the patient’s<br />
position <strong>of</strong> LLD (Lateral<br />
Left Dicubitus)<br />
For RPH Yogyakarta, the pause time is assumed<br />
10 m<strong>in</strong>utes, sh<strong>in</strong><strong>in</strong>g is conducted for 144 times each<br />
day, 7 days a week, at each exposure uses the current<br />
rate <strong>of</strong> 40 mAs,70 kV. So the total number <strong>of</strong> exposure<br />
is 1008 times per week.<br />
Workload W = 1008 exposure/week X 40mAs:<br />
60(m<strong>in</strong>/s)<br />
= 672 mA.m<strong>in</strong>/week<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
Calculat<strong>in</strong>g the thickness <strong>of</strong> Shield<strong>in</strong>g for<br />
Primary Radiation<br />
P (maximum exposure allowed) is 0.1 (for<br />
controlled area), and 0.01 (for uncontrolled<br />
area), the distance (d) = 2 m, W= 672<br />
mA.m<strong>in</strong>/week, U (Use Factor) = for wall and<br />
1 for floor.<br />
T (Occupancy Factor) : 1<br />
(active room)<br />
a.Wall A = primary radiation = horizontal beam<br />
Kwall A = 0.002 R/mA-m<strong>in</strong> = 2 x 10 -3<br />
R/mA-m<strong>in</strong>.<br />
Based on reference 6, to obta<strong>in</strong> the required<br />
attenuation for the curve 125 kVp we need the<br />
lead (Pb) thickness <strong>of</strong> 1.5 mm while to get the<br />
same attenuation for concrete the thickness<br />
needed is 12.7 cm.<br />
b.Floor = primary radiation = Vertical Beam<br />
Kfloor = 0.000067 R/mA-men = 7 x 10 -3 R/mAm<strong>in</strong>.<br />
Based on reference 8, the thickness required is<br />
2.8 mm for lead or 21.895 cm for concrete.<br />
Calculat<strong>in</strong>g the thickness <strong>of</strong> Shield<strong>in</strong>g for<br />
Secondary Radiation<br />
Wall B<br />
a. Wall B = scattered radiation = Vertical<br />
beam<br />
Given:<br />
P = 0.01 R (uncontrolled area)<br />
W = 672 mA-m<strong>in</strong>/week<br />
dSCA = 1 m<br />
T = 1<br />
dSEC = 1.4 m<br />
F = 38.3087 cm 2<br />
a = 0.0015 (90 O )<br />
f = 1<br />
= 0.2072<br />
KUX<br />
Based on reference 6, the thickness required for<br />
radiation shield<strong>in</strong>g is 0.2 mm for lead or 0.5 cm<br />
for concrete.<br />
b.Wall B = scattered radiation = Horizontal<br />
beam<br />
Given:<br />
P = 0.01 R (uncontrolled area)<br />
W = 672 mA-m<strong>in</strong>/week<br />
dSCA = 1.5 m<br />
T = 1<br />
dSEC = 1.803 m<br />
F = 86.1948 cm 2<br />
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a = 0.0015 (45 O )<br />
f = 1<br />
e. Wall B = leaked radiation = Vertical beam<br />
KUX = 0,3367<br />
Given:<br />
P = 0.01 R (uncontrolled area)<br />
From the curve for 125 kVp the required thickness for W = 672 mA-m<strong>in</strong>/week<br />
radiation shield<strong>in</strong>g is 0.13 mm for lead or 0 cm for d = 1.414 m<br />
concrete.<br />
T = 1<br />
I = 125 mA<br />
c.Wall B = scattered radiation = Horizontal beam<br />
BLx = 2.2315<br />
BLx = ½ n<br />
Given:<br />
2.2315 = ½ n<br />
P = 0.01 R (uncontrolled area)<br />
W = 672 mA-m<strong>in</strong>/week<br />
n = -0.2895<br />
dSCA = 1.5 m<br />
T = 1 Because the result <strong>of</strong> n is negative, then the<br />
dSEC = 1.803 m<br />
leaked radiation is not taken <strong>in</strong>to account, so<br />
F = 86.1948 cm that there is not shield<strong>in</strong>g required for leaked<br />
radiation.<br />
2<br />
a = 0.0015(90 O )<br />
f = 1<br />
KUX = 0,3367 f. Wall B = leaked radiation = Horizontal beam<br />
Given :<br />
From the curve for 125 kVp the required thickness for P = 0.01 R<br />
radiation shield<strong>in</strong>g is 0.13 mm for lead or 0 cm for W = 672 mA-m<strong>in</strong>/week<br />
concrete.<br />
d = 1.803 m<br />
T = 1<br />
d. Wall B = scattered radiation = Horizontal beam<br />
I = 125 mA<br />
Given:<br />
BLx<br />
BLx<br />
= 3.628<br />
= ½ n<br />
P = 0.01 R (uncontrolled area)<br />
3.628 = ½ n<br />
W = 672 mA-m<strong>in</strong>/week<br />
dSCA = 1.5 m n = -0.4648<br />
T = 1<br />
dSEC = 1.803 m Aga<strong>in</strong>, because the result <strong>of</strong> n is negative, then<br />
F = 86.1948 cm the leaked radiation is not taken <strong>in</strong>to account, so<br />
that there is not shield<strong>in</strong>g required for leaked<br />
radiation.<br />
2<br />
a = 0.0025 (135 O )<br />
f = 1<br />
KUX = 0.2020 <strong>The</strong> safe distances for radiation exposure from<br />
the mobile X-ray mach<strong>in</strong>es <strong>in</strong> the three hospitals<br />
From the curve for 125 kVp the required thickness for<br />
radiation shield<strong>in</strong>g is 0.2 mm for lead or 0.5 cm for<br />
concrete.<br />
can be seen <strong>in</strong> the tables below.<br />
No Tube<br />
position<br />
Table 2. Result <strong>of</strong> measurement mobile x-ray mach<strong>in</strong>e <strong>in</strong> RPH Senopati Bantul<br />
Patient’s<br />
bed<br />
position<br />
1 Vertical Beside<br />
tube<br />
2 Axial<br />
35 0<br />
Beside<br />
tube<br />
Distance<br />
patient’s<br />
bed<br />
r1(m)<br />
Average<br />
Dose<br />
scatter<br />
(mrem)<br />
D1<br />
(mre<br />
m/s)<br />
DVL (D2)<br />
Mrem/s<br />
2.24 0.018 0.009 694E-6(worker)<br />
208E-6(staff)<br />
694E-6(public)<br />
2.24 0.01 0.005 694E-6(worker)<br />
208E-6(staff)<br />
694E-6(public)<br />
2<br />
D xr<br />
D<br />
2<br />
1 1<br />
Safe<br />
distance (m)<br />
8.06<br />
14.73<br />
25.51<br />
6.01<br />
10.98<br />
19.01<br />
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January 24, 2009<br />
3 Axial<br />
35 0<br />
4 horizon<br />
tal<br />
5 horizon<br />
tal<br />
No Tube<br />
position<br />
Beh<strong>in</strong>d<br />
tube<br />
Beside<br />
tube<br />
Beh<strong>in</strong>d<br />
tube<br />
1.41 0.00 0.000 694E-6(worker)<br />
208E-6(staff)<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
694E-6(public)<br />
2.24 0.01 0.005 694E-6(worker)<br />
208E-6(staff)<br />
694E-6(public)<br />
1.41 0.00 0.000 694E-6(worker)<br />
208E-6(staff)<br />
694E-6(public)<br />
Table 3. Result <strong>of</strong> measurement mobile x-ray mach<strong>in</strong>e <strong>in</strong> RPH Sleman<br />
Patient’s<br />
bed<br />
position<br />
1 Vertical Beside<br />
tube<br />
2 Axial<br />
35 0<br />
3 Axial<br />
35 0<br />
4 horizon<br />
tal<br />
5 horizon<br />
tal<br />
Beside<br />
tube<br />
Beh<strong>in</strong>d<br />
tube<br />
Beside<br />
tube<br />
Beh<strong>in</strong>d<br />
tube<br />
Distance<br />
patient’s<br />
bed<br />
r1(m)<br />
Average<br />
Dose<br />
scatter<br />
(mrem)<br />
D1<br />
(mre<br />
m/s)<br />
DVL (D2)<br />
Mrem/s<br />
2.24 0.018 0.009 694E-6(worker)<br />
208E-6(staff)<br />
694E-6(public)<br />
2.24 0.014 0.007 694E-6(worker)<br />
208E-6(staff)<br />
694E-6(public)<br />
1.41 0.00 0.000 694E-6(worker)<br />
208E-6(staff)<br />
694E-6(public)<br />
2.24 0.04 0.002 694E-6(worker)<br />
208E-6(staff)<br />
694E-6(public)<br />
1.41 0.00 0.000 694E-6(worker)<br />
208E-6(staff)<br />
694E-6(public)<br />
Safe<br />
6.01<br />
10.98<br />
19.01<br />
Safe<br />
r =<br />
2<br />
Safe<br />
distance (m)<br />
8.07<br />
14.73<br />
25.51<br />
7.11<br />
12.99<br />
22.50<br />
Safe<br />
3.80<br />
6.94<br />
12.02<br />
Safe<br />
Table 4. Result <strong>of</strong> measurement mobile x-ray mach<strong>in</strong>e <strong>in</strong> RPH Wonosari Gunung Kidul<br />
No Tube<br />
position<br />
Patient’s<br />
bed<br />
position<br />
1 Vertical Beside<br />
tube<br />
2 Axial<br />
35 0<br />
3 Axial<br />
35 0<br />
4 horizon<br />
tal<br />
Beside<br />
tube<br />
Beh<strong>in</strong>d<br />
tube<br />
Beside<br />
tube<br />
Distance<br />
patient’s<br />
bed<br />
r1(m)<br />
Average<br />
Dose<br />
scatter<br />
(mrem)<br />
D1<br />
(mre<br />
m/s)<br />
DVL (D2)<br />
Mrem/s<br />
2.24 0.01 0.005 694E-6(worker)<br />
208E-6(staff)<br />
694E-6(public)<br />
2.24 0.01 0.005 694E-6(worker)<br />
208E-6(staff)<br />
694E-6(public)<br />
1.41 0.00 0.000 694E-6(worker)<br />
208E-6(staff)<br />
694E-6(public)<br />
2.24 0.002 0.005 694E-6(worker)<br />
208E-6(staff)<br />
694E-6(public)<br />
D xr<br />
D<br />
2<br />
1 1<br />
Safe<br />
distance (m)<br />
6.01<br />
10.98<br />
19.01<br />
6.01<br />
10.98<br />
19.01<br />
Safe<br />
3.80<br />
6.94<br />
12.02<br />
Proceed<strong>in</strong>g Book 517<br />
r =<br />
2<br />
2<br />
D xr<br />
D<br />
2<br />
1 1<br />
2
<strong>The</strong> First International Sem<strong>in</strong>ar on Science and Technology<br />
January 24, 2009<br />
5 horizon<br />
tal<br />
Beh<strong>in</strong>d<br />
tube<br />
1.41 0.00 0.000 694E-6(worker)<br />
208E-6(staff)<br />
694E-6(public)<br />
Us<strong>in</strong>g the formulations above, the shield<strong>in</strong>g can presented <strong>in</strong> the table below.<br />
Location K (R/<br />
Table 5. Result <strong>of</strong> thick shield<strong>in</strong>g calculation for structural shield<strong>in</strong>g<br />
mA - m<strong>in</strong>ut<br />
week<br />
Floor / Primer 6 . 10 -5<br />
Wall A / Primer 2 . 10 -3<br />
Wall B/ scatter<strong>in</strong>g 2.07 . 10 -1<br />
3.37 . 10<br />
Wall B/ scatter<strong>in</strong>g<br />
-1<br />
3.37 . 10 -1<br />
2.02 . 10 -1<br />
Wall C/ scatter<strong>in</strong>g 1.295 . 10 -1<br />
5.18 . 10<br />
Wall C/ scatter<strong>in</strong>g<br />
-1<br />
5.18 . 10 -1<br />
3.11 . 10 -1<br />
Wall D/ scatter<strong>in</strong>g 3.367 . 10 -1<br />
4.656 . 10<br />
Wall D/ scatter<strong>in</strong>g<br />
-1<br />
4.656 . 10 -1<br />
2.793 . 10 -1<br />
Ceil<strong>in</strong>g /scatter<strong>in</strong>g 3.7291<br />
Ceil<strong>in</strong>g /scatter<strong>in</strong>g 7.3090<br />
) Direction<br />
Thickness(mm)<br />
Lead<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
Safe<br />
Thickness<br />
(cm)<br />
concrete<br />
Vertical 2.,8 21.895<br />
Horizontal 1.5 12.7<br />
Vertical 0.2 0.5<br />
0.13<br />
0<br />
Horizontal 0.13<br />
0<br />
0.2<br />
0.5<br />
Vertical 0.33 0<br />
0.06<br />
0<br />
Horizontal 0.06<br />
0<br />
0.13<br />
0<br />
Vertical 0.13<br />
0.1<br />
0<br />
Horizontal<br />
0.1<br />
0.13<br />
0<br />
Vertical 0 0<br />
Horizontal 0 0<br />
Table 6. <strong>The</strong> calculation <strong>of</strong> Leak radiation<br />
Location Direction BLx = ½ n<br />
= P x (d)² x 600 x I<br />
N<br />
W x T<br />
Wall B Vertical 2.2315 -0.2895<br />
Horizontal 3.6280 -0.4648<br />
Wall C Vertical 1.3950 -0.1201<br />
Horizontal 5.5800 -0.6201<br />
Wall D Vertical 3.2810 -0.4649<br />
Horizontal 5.0161 -0.5817<br />
Ceil<strong>in</strong>g Vertical 151.7882 -1.8117<br />
Horizontal 111.6071 -1.7007<br />
Discussion<br />
NCRP (National Council on Radiological<br />
Protection and Measurement) recommends that the<br />
maximum permissible dose is 25 µSv/hr (2.5 mrem/hr)<br />
for radiation workers, 7.5 µSv/hr for staff, and 2,5<br />
µS3v/hr.(0.25 mrem/hr) for public [6] . In this research,<br />
us<strong>in</strong>g the closest distance assumption among the<br />
patient’s beds 1,5 meters and FFD 1 meter, it<br />
was found that the distance <strong>of</strong> r2 was 1.80<br />
meters from the tube. After that, the results <strong>of</strong><br />
calculat<strong>in</strong>g the dosage rate (D2) <strong>in</strong> each hospital<br />
can be seen <strong>in</strong> Table 7, 8 and 9.<br />
Proceed<strong>in</strong>g Book 518
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January 24, 2009<br />
No Tube position<br />
1.<br />
2.<br />
3.<br />
4.<br />
5.<br />
Vertical<br />
Axial 35 0<br />
Axial 35 0<br />
Horizontal<br />
Horizontal<br />
No Tube position<br />
1.<br />
2.<br />
3.<br />
4.<br />
5.<br />
Vertical<br />
Axial 35 0<br />
Axial 35 0<br />
Horizontal<br />
Horizontal<br />
No Tube position<br />
1.<br />
2.<br />
3.<br />
4.<br />
5.<br />
Vertical<br />
Axial 35 0<br />
Axial 35 0<br />
Horizontal<br />
Horizontal<br />
D1<br />
(mrem/s)<br />
0.009<br />
0.005<br />
0.000<br />
0.005<br />
0.000<br />
Table 7. Dose rate <strong>in</strong> RPH Senopati Bantul<br />
r1<br />
(m)<br />
2.24<br />
2.24<br />
1.41<br />
2.24<br />
1.41<br />
Patient’s bed<br />
Beside tube<br />
Beside tube<br />
Beh<strong>in</strong>d tube<br />
Beside tube<br />
Beh<strong>in</strong>d tube<br />
Table 8. Dose rate <strong>in</strong> RPH Sleman<br />
D1<br />
(mrem/s)<br />
0.009<br />
0.007<br />
0.000<br />
0.002<br />
0.000<br />
r1<br />
(m)<br />
2.24<br />
2.24<br />
1.41<br />
2.24<br />
1.41<br />
Patient’s bed<br />
Beside tube<br />
Beside tube<br />
Beh<strong>in</strong>d tube<br />
Beside tube<br />
Beh<strong>in</strong>d tube<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
r2<br />
(m)<br />
1.80<br />
1.80<br />
1.80<br />
1.80<br />
1.80<br />
Table 9. Dose rate <strong>in</strong> RPH Wonosari Gunung Kidul<br />
D1<br />
(mrem/s)<br />
0.005<br />
0.005<br />
0.000<br />
0.002<br />
0.000<br />
r1<br />
(m)<br />
2.24<br />
2.24<br />
1.41<br />
2.24<br />
1.41<br />
Based on the tables above, calculat<strong>in</strong>g the<br />
design <strong>of</strong> safe structural barrier <strong>in</strong> the U-form (see <strong>in</strong><br />
Fig 3 & Table 5), the highest load is for RPH Sleman,<br />
which is then taken as the standard for the other two<br />
hospitals for more safety. <strong>The</strong> calculation result<br />
requires the structural barrier with the thickness <strong>of</strong> 1.5<br />
mm (rounded to 2 mm) for lead wall or 16 cm for<br />
concrete wall, and 2.8 mm for lead floor [6] .<br />
Conclusion<br />
1. <strong>The</strong> assumption that the closest distance among<br />
the patient beds is 1.5 meters beside the tube<br />
proved to be unsafe for the workers. <strong>The</strong> closest<br />
safe distance beside the tube is 3.80 meters for the<br />
workers and is 12.02 meters for public. While for<br />
the position beh<strong>in</strong>d the tube, the closest safe<br />
distance for both the workers and public is 1.41<br />
meters.<br />
Patient’s bed<br />
Beside tube<br />
Beside tube<br />
Beh<strong>in</strong>d tube<br />
Beside tube<br />
Beh<strong>in</strong>d tube<br />
r2<br />
(m)<br />
1.80<br />
1.80<br />
1.80<br />
1.80<br />
1.80<br />
D2<br />
(mrem/s)<br />
0.0139<br />
0.0077<br />
0.0000<br />
0.0077<br />
0.0000<br />
r2<br />
(m)<br />
1.80<br />
1.80<br />
1.80<br />
1.80<br />
1.80<br />
D2<br />
(mrem/s)<br />
0.0077<br />
0.0077<br />
0.0000<br />
0.0031<br />
0.0000<br />
D2<br />
(mrem/s)<br />
0.0139<br />
0.0108<br />
0.0000<br />
0.0031<br />
0.0000<br />
2. Based on the calculation, the m<strong>in</strong>imum<br />
thickness required for safety shield for the<br />
primer radiation is 1.5 mm for lead (Pb)<br />
wall or 16 cm for concrete wall, and 2.8<br />
mm for lead floor.<br />
References<br />
(1) NCRP, 2004, Structural Shield<strong>in</strong>g<br />
Design for Medical X-ray Imag<strong>in</strong>g<br />
Facilities, Report No. 147 (Revised<br />
March 2005), NCRP Bethesda, MD.<br />
(2) Abid<strong>in</strong> Z.,Toto K.& Taufiq Z.,2008, <strong>The</strong><br />
Operation <strong>of</strong> X-ray Mobile Unit <strong>in</strong> Three<br />
Local Public Hospital <strong>in</strong> Yogyakarta,<br />
Proceed<strong>in</strong>g Sem<strong>in</strong>ar NHI >N, ISSN<br />
No 1693-3346 page 119-125, Jakarta.<br />
(3) Taufiq Z, 2008, <strong>The</strong> Analysis <strong>of</strong> Safety <strong>in</strong><br />
<strong>The</strong> Operation <strong>of</strong> X-Ray Mobile Unit <strong>in</strong><br />
<strong>The</strong> Care Room <strong>of</strong> <strong>The</strong> Regional State<br />
Proceed<strong>in</strong>g Book 519
<strong>The</strong> First International Sem<strong>in</strong>ar on Science and Technology<br />
January 24, 2009<br />
Hospital <strong>in</strong> Yogyakarta, F<strong>in</strong>al Report <strong>in</strong> POIN,<br />
Yogyakarta.<br />
(4) Cember H, Introduction to Health Physics,<br />
Second Edition, Pergamon Press, 1985. .<br />
(5) Simpk<strong>in</strong> DJ, Dixon RL. Secondary Shield<strong>in</strong>g<br />
Barriers for Diagnostic X-Ray Facilities:<br />
Scatter and Leakage Revisited. Health Phys<br />
1998;74:350–65.<br />
Figure 2 Scheme <strong>of</strong> the exist<strong>in</strong>g shield<strong>in</strong>g <strong>in</strong> most hospital<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
(6) NCRP, 1976, Structural Shield<strong>in</strong>g<br />
Design and Evaluation, Report No. 49<br />
(September 1976), NCRP<br />
(7) Bumiasih T, 2008, <strong>The</strong> Design <strong>of</strong> <strong>The</strong><br />
Radiation Shield<strong>in</strong>g <strong>of</strong> <strong>The</strong> X-Ray<br />
Generator <strong>in</strong> Distric General Hospital<br />
Yogyakarta City, F<strong>in</strong>al Report <strong>in</strong> POIN,<br />
Yogyakarta.<br />
Proceed<strong>in</strong>g Book 520
<strong>The</strong> First International Sem<strong>in</strong>ar on Science and Technology<br />
January 24, 2009<br />
Wall D Wall B<br />
Peep<strong>in</strong>g w<strong>in</strong>dow<br />
Wall C<br />
Wall D. Side orientation<br />
Support<strong>in</strong>g frame made from steel plat <strong>of</strong> 3 mm thick and<br />
3,2 cm wide<br />
Figure 3 Design <strong>of</strong> Structural Shield<strong>in</strong>g<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
Proceed<strong>in</strong>g Book 521
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January 24, 2009<br />
Introduction<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
MgF2 as Catalyst and Support on Phenol Acylation<br />
Nisa Nur<strong>in</strong>a Valerie and Irm<strong>in</strong>a Kris Murwani *<br />
Chemistry <strong>Study</strong> Program, Faculty <strong>of</strong> Mathematics and Natural Sciences,<br />
Sepuluh Nopember Institute <strong>of</strong> Technology,<br />
Keputih <strong>ITS</strong> Campuss, Sukolilo, Surabaya, Indonesia, 60111.<br />
*e-mail : irm<strong>in</strong>a@chem.its.ac.id<br />
Abstract<br />
<strong>The</strong> us<strong>in</strong>g <strong>of</strong> MgF 2 as catalyst and support for phenol acylation with acetic acid has been studied. <strong>The</strong><br />
reaction is an alternative method to reduce the phenol concentration. Generally, the acylation reactions<br />
<strong>in</strong>volve the use <strong>of</strong> Lewis acid catalysts. MgF 2 is one <strong>of</strong> the non toxic Lewis acid catalysts. MgF 2 <strong>in</strong> this<br />
research were prepared and characterized us<strong>in</strong>g X-ray diffraction (XRD), Fourier Transform <strong>in</strong>frared<br />
spectroscopy (FTIR) and measurement <strong>of</strong> specific surface area with N 2 adsorption. <strong>The</strong> catalytic activities<br />
were determ<strong>in</strong>ed based on phenol conversion. Result <strong>of</strong> this research <strong>in</strong>dicated that MgF 2 and CuO/MgF 2<br />
serve the purpose <strong>of</strong> supported catalyst with phenol conversion 95.23 and 90.53%, respectively. This<br />
conversion value showed a l<strong>in</strong>ear correlation with its specific surface area, that is 31.38 and 12.75 m 2 /g,<br />
respectively. Analysis <strong>of</strong> phenol acylation us<strong>in</strong>g HPLC showed that acetophenone was the ma<strong>in</strong> product<br />
with selectivity MgF 2 45.37% and CuO/MgF 2 52.32%.<br />
Keywords: Catalyst, MgF 2, phenol acylation, support.<br />
Phenol acylation is an important and frequently used<br />
organic transformation as it provides not only an<br />
efficient and <strong>in</strong>expensive route for the protect<strong>in</strong>g<br />
hydroxy group but also produced important organic<br />
<strong>in</strong>termediates <strong>in</strong> multi-step synthetic processes which<br />
are widely used <strong>in</strong> the synthesis <strong>of</strong> f<strong>in</strong>e chemicals,<br />
pharmaceuticals, perfumes, plasticizers, cosmetics,<br />
chemical auxiliaries, etc. [6]. Hidroxyacetophenones<br />
(HAP) which are useful <strong>in</strong>termediates for the<br />
manufacture <strong>of</strong> pharmaceuticals can be obta<strong>in</strong>ed<br />
through catalytic rearrangement <strong>of</strong> phenyl acetate or<br />
direct acylation <strong>of</strong> phenol by acetic acid [9]. In<br />
particular, p-HAP is widely used for the synthesis <strong>of</strong><br />
paracetamol and o-HAP is a key <strong>in</strong>termediate for<br />
produc<strong>in</strong>g 4-hydroxycoumar<strong>in</strong> and warfar<strong>in</strong>, which<br />
are both, used as anticoagulant drugs [8]. Acylation is<br />
normally achieved by treatment with acetic acid <strong>in</strong> the<br />
presence <strong>of</strong> suitable catalysts. Homogeneous catalysts<br />
such as AlCl3, CoCl2, CuCl2, FeCl3 and TiCl5 have<br />
been used for the acylation <strong>of</strong> phenol. However, one<br />
<strong>of</strong> the major problems <strong>in</strong> homogeneous reaction is the<br />
separation <strong>of</strong> the catalyst from the reaction mixture.<br />
Heterogeneous catalysts are found to be very good<br />
alternatives to the problems associated with proton<br />
acids (Lewis acids) or Friedel-Crafts type catalysts<br />
[2,8,12]. Phenol acylation with acetic acid over MgF2<br />
and copper oxide catalyst supported on MgF2 was<br />
<strong>in</strong>vestigated. <strong>The</strong> aim <strong>of</strong> this <strong>in</strong>vestigation is also to<br />
study the effect <strong>of</strong> copper oxides on MgF2 dur<strong>in</strong>g<br />
acylation. <strong>The</strong> catalysts were characterized by various<br />
techniques like XRD, FTIR and BET surface area.<br />
MgF2 as Lewis acid is one candidate as support and<br />
catalyst.<br />
Materials and Methods<br />
Catalyst preparation and characterization<br />
Magnesium fluoride was prepared accord<strong>in</strong>g to the<br />
literature [14]. <strong>The</strong> copper oxides catalyst supported<br />
on MgF2 was prepared by wet impregnation method.<br />
<strong>The</strong> support was impregnated with Cu(ClO4)2 <strong>in</strong><br />
water followed by dry<strong>in</strong>g. This precursor was<br />
activated by calc<strong>in</strong>ations at 400°C for 4 h. Catalysts<br />
characterization was carried out by means <strong>of</strong> XRD,<br />
FTIR and BET. XRD characterization was performed<br />
us<strong>in</strong>g XRD JEOL JDX-3530 (Cu Kα). FTIR<br />
characterization was performed us<strong>in</strong>g Shimadzu<br />
FTIR-8400S with DRS-8000. Specific surface areas<br />
were determ<strong>in</strong>ed by means <strong>of</strong> N2 adsorption measured<br />
with Quantachrome NovaW<strong>in</strong>2-Data Acquisition and<br />
Red for NOVA <strong>in</strong>struments version 2.1.<br />
Catalytic activity on phenol acylation<br />
Proceed<strong>in</strong>g Book 522
<strong>The</strong> First International Sem<strong>in</strong>ar on Science and Technology<br />
January 24, 2009<br />
<strong>The</strong> catalytic properties <strong>of</strong> the catalysts were<br />
determ<strong>in</strong>ed us<strong>in</strong>g HPLC method. Phenol acylation<br />
were carried out <strong>in</strong> magnetically stirred glass reactor<br />
at the follow<strong>in</strong>g reaction conditions: reaction mixture<br />
= catalyst + acetic acid + phenol, temperature = 25°C,<br />
reaction period = 15 m<strong>in</strong>utes. <strong>The</strong> catalytic activity<br />
was observed based on concentration <strong>of</strong> phenol<br />
conversion. <strong>The</strong> catalytic selectivity was observed<br />
based on acetophenone product formed.<br />
Results and Discussion<br />
MgF2 Catalyst<br />
This paper reports results on obta<strong>in</strong><strong>in</strong>g magnesium<br />
fluoride <strong>in</strong> the sol-gel reaction <strong>of</strong> magnesium nitrate<br />
hexahydrate and hydr<strong>of</strong>luoric acid, accord<strong>in</strong>g to the<br />
equation below:<br />
Mg(NO3)2.6H2O + 2HF → MgF2 + 2HNO3 +<br />
6H2O<br />
Powder X-ray diffractogram <strong>of</strong> MgF2 is shown<br />
<strong>in</strong> Fig. 1. <strong>The</strong> sharp diffraction l<strong>in</strong>es at d = 3.275 Å,<br />
2.231 Å and 1.711 Å (2θ values are 27.2°, 40.4° and<br />
53.5°, respectively) are due to the tetragonal form <strong>of</strong><br />
magnesium fluoride (PDF No. 06-0290). No<br />
diffraction l<strong>in</strong>es noticed correspond<strong>in</strong>g to<br />
Mg(NO3)2·6H2O, MgO or other contam<strong>in</strong>ants<br />
detected.<br />
Fig. 1. X-ray diffractogram <strong>of</strong> MgF2<br />
FTIR spectra <strong>of</strong> magnesium fluoride is shown <strong>in</strong><br />
Fig. 2. A stretch<strong>in</strong>g vibration for the O–H bond<br />
appears at 3600-3200 cm -1 . A bend<strong>in</strong>g vibration <strong>of</strong><br />
the H–O–H bond appears at 1648.2 cm -1 [5]. Dur<strong>in</strong>g<br />
the preparation <strong>of</strong> magnesium fluoride, or when it is<br />
contacted with water vapour, water dipoles <strong>in</strong>teract<br />
with coord<strong>in</strong>atively unsaturated Mg ions and fill their<br />
coord<strong>in</strong>ation sphere. This leads to the formation <strong>of</strong><br />
surface hydroxyls. <strong>The</strong> stretch<strong>in</strong>g vibration for the<br />
Mg–F bond appears at 1200 cm -1 , 1000 cm -1 , 730 cm -<br />
1 and 458 cm -1 [3,11,14].<br />
CuO/MgF2 catalyst<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
Fig. 2. FTIR spectra <strong>of</strong> MgF2<br />
<strong>The</strong> impregnated sample was dark gray <strong>in</strong> color,<br />
which suggests that copper oxide phase exists <strong>in</strong> the<br />
sample. <strong>The</strong> copper oxide phase was formed dur<strong>in</strong>g<br />
calc<strong>in</strong>ations [13]. <strong>The</strong> X-ray diffraction patterns <strong>of</strong><br />
CuO/MgF2 and MgF2 are presented <strong>in</strong> Fig. 3 below.<br />
<strong>The</strong> XRD pr<strong>of</strong>ile <strong>of</strong> CuO/MgF2 sample exhibits the<br />
characteristic features <strong>of</strong> copper oxide as monocl<strong>in</strong>ic<br />
phase (PDF No. 72-0629) with the characteristic<br />
peaks at at d = 2.5226 Å, 2.3217 Å and 1.7113 Å (2θ<br />
values are 35.6°, 38.7° and 53.5°, respectively) and<br />
the characteristic features <strong>of</strong> magnesium fluoride as<br />
tetragonal phase (PDF No. 06-0290) with the<br />
characteristic peaks at 2θ = 27.2°, 40.4° and 53.5°.<br />
Fig. 3. X-ray diffractograms <strong>of</strong> CuO/MgF2 and<br />
MgF2 (, : CuO)<br />
<strong>The</strong> copper oxide phase giv<strong>in</strong>g strong reflections<br />
only at 2θ = 38.7° appeared <strong>in</strong> the sample prepared<br />
by impregnation with copper load<strong>in</strong>g <strong>of</strong> 2.35 wt. %.<br />
Diffraction pattern <strong>of</strong> CuO/MgF2 show a strong<br />
characteristic features <strong>of</strong> MgF2. This <strong>in</strong>dicated that<br />
the CuO species particles, which are amorphous or<br />
very small, are highly dispersed with<strong>in</strong> the matrix [5].<br />
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<strong>The</strong> FTIR spectra <strong>of</strong> CuO/MgF2 reported <strong>in</strong> Fig.<br />
4. <strong>The</strong> spectra have a broad absorption band at<br />
approximately 3550-3200 cm -1 , which is assigned to<br />
the O–H stretch<strong>in</strong>g vibration <strong>of</strong> waters. Similarly, the<br />
band near 1630-1600 cm -1 is associated with the<br />
bend<strong>in</strong>g mode <strong>of</strong> O–H groups <strong>of</strong> adsorbed water [5].<br />
<strong>The</strong> stretch<strong>in</strong>g vibration for Cu–O bond appears at<br />
1500 cm -1 and 500 cm -1 [4,13] and the stretch<strong>in</strong>g<br />
vibration <strong>of</strong> Mg–F appears at 1000 cm -1 , 730 cm -1 and<br />
458 cm -1 [3,11,14].<br />
Fig. 4. FTIR spectra <strong>of</strong> CuO/MgF2<br />
Surface area measurement<br />
<strong>The</strong> specific surface areas <strong>of</strong> the catalysts is given <strong>in</strong><br />
Table 1. <strong>The</strong> data <strong>in</strong>dicate that the impregnation <strong>of</strong><br />
magnesium fluoride with an aqueous solution <strong>of</strong><br />
copper perchlorate reduces the surface area and the<br />
pore volume <strong>of</strong> the samples, while <strong>in</strong>creas<strong>in</strong>g the pore<br />
size. This is probably due to a certa<strong>in</strong> contribution <strong>of</strong><br />
the CuO to the total surface area: a microporous<br />
system is not well developed <strong>in</strong> CuO (surface area<br />
1,10 m 2 /g) [5]. CuO/MgF2 showed a clear decrease <strong>in</strong><br />
surface areas and average pore diameters relative to<br />
their supports. This is expected because the pores <strong>in</strong><br />
each support are partially filled by copper oxide<br />
particles.<br />
Table 1. BET characterization <strong>of</strong> MgF2 and<br />
CuO/MgF2<br />
Catalyst Surface Area (m 2 /g)<br />
MgF2<br />
31,38<br />
CuO/ MgF2<br />
12,75<br />
Catalytic activity on phenol acylation<br />
<strong>The</strong> catalytic activity <strong>of</strong> samples was exam<strong>in</strong>ed <strong>in</strong><br />
phenol acylation with acetic acid us<strong>in</strong>g HPLC<br />
method. Acetic acid can be employed as acylat<strong>in</strong>g<br />
agent because stable and its handl<strong>in</strong>g are easier than<br />
acetic anhydrides [9]. Phenol acylation under solvent<br />
free condition and the us<strong>in</strong>g <strong>of</strong> acetic acid as<br />
acylat<strong>in</strong>g agent, hence reaction can take place faster<br />
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[6]. Phenol acylation done at optimum condition<br />
obta<strong>in</strong>ed maximum catalyst activity. Activity is<br />
ability <strong>of</strong> catalyst <strong>in</strong> conversion reactant to become<br />
product wanted. Catalyst activity was determ<strong>in</strong>ed<br />
based on concentration <strong>of</strong> phenol conversion that<br />
measured based on concentration <strong>of</strong> rema<strong>in</strong>s phenol.<br />
Phenol detected on HPLC is phenol that was not<br />
reacted or rema<strong>in</strong>s phenol. Smaller concentration <strong>of</strong><br />
rema<strong>in</strong><strong>in</strong>g phenol, hence ever greater converted<br />
phenol yielded. Optimum conditions at phenol<br />
acylation as accord<strong>in</strong>g to report from [6], at<br />
temperature 25°C for 15 m<strong>in</strong>utes. Fig. 6 presents the<br />
activity and selectivity <strong>of</strong> MgF2 and CuO/MgF2<br />
catalysts.<br />
Fig. 6. <strong>The</strong> activity and selectivity <strong>of</strong> MgF2 and<br />
CuO/MgF2 at room temperature<br />
Higher conversion was obta<strong>in</strong>ed for catalyst MgF2<br />
reach 95.23%. <strong>The</strong> activity <strong>of</strong> copper oxide catalyst<br />
supported on MgF2 was lower with phenol<br />
conversion reach 90.53%. Introduction <strong>of</strong> copper<br />
oxide caused a decrease <strong>in</strong> catalytic activity. <strong>The</strong><br />
degree <strong>of</strong> conversion depends on the surface area <strong>of</strong><br />
catalysts, where MgF2 shows surface area was higher<br />
than CuO/MgF2. Phenol conversion also can yield<br />
acetophenone product [1]. <strong>The</strong> copper oxide catalyst<br />
supported on MgF2 have proved more selective <strong>in</strong><br />
phenol acylation than those MgF2 itself. Highest<br />
product <strong>of</strong> acetophenone was obta<strong>in</strong>ed by CuO/MgF2<br />
and decl<strong>in</strong>es when applied by MgF2. From the above<br />
characterization <strong>of</strong> catalysts, we conclude that the<br />
differences <strong>of</strong> selectivity would not be related to the<br />
specific surface area data. <strong>The</strong> state and distribution<br />
<strong>of</strong> Cu species <strong>in</strong> the catalysts are the key factors to<br />
the reaction. Based on the above results, we can<br />
conclude that the catalytic activity was related to the<br />
surface area <strong>of</strong> catalysts. All catalysts showed good<br />
catalytic activity for phenol acylation, which can be<br />
ascribed to the highest activity <strong>of</strong> each catalyst.<br />
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Conclusion<br />
MgF2 proved to be an <strong>in</strong>terest<strong>in</strong>g catalyst and<br />
support for copper oxide catalyst <strong>in</strong> phenol acylation.<br />
This result can be ascribed to the highest activity <strong>of</strong><br />
each catalyst. <strong>The</strong> experiment results showed that<br />
percentage <strong>of</strong> phenol conversions us<strong>in</strong>g the MgF2 and<br />
CuO/MgF2 catalysts were 95.23 and 90.53%,<br />
respectively. This conversion showed a l<strong>in</strong>ear<br />
correlation with surface area <strong>of</strong> each catalyst, that is<br />
31.38 and 12.75 m 2 /g, for MgF2 and CuO/MgF2,<br />
respectively. Analysis <strong>of</strong> the acylation product<br />
showed that the acetophenone was the ma<strong>in</strong> product<br />
<strong>of</strong> the acylation with selectivity MgF2 45.37% and<br />
CuO/MgF2 52.32%.<br />
Acknowledgements<br />
We gratefully the support from LPPM <strong>ITS</strong> for<br />
f<strong>in</strong>ancial support<br />
References<br />
[1] Baltrok, I.M., Aliyan, H., Khosropuur, A.R.<br />
2001. Bismuth(III) salts as convenient and<br />
efficient catalysts for the selective acetylation<br />
and benzylation <strong>of</strong> alcohols and phenol.<br />
Tetrahedron Lett. 57: 5851-5854.<br />
[2] Chandrasekhar, S., Ramachander, T., Takhi,<br />
M. 1998. Acylation <strong>of</strong> alcohols with acetic<br />
anhydride catalyzed by TaCl5: Some<br />
implications <strong>in</strong> k<strong>in</strong>etic resolution. Tetrahedron<br />
Lett. 39: 3263-3266.<br />
[3] Cho, D.H., Yim, S.D., Cha, G.H., Lee, J.S.,<br />
Kim, Y.G., Chung, J.S., Nam, I.S. 1998.<br />
Behavior <strong>of</strong> chromium oxide on MgO or<br />
MgF2. J. Phys. Chem. A. 102: 7913-7918.<br />
[4] El-Bahy. 2007, Oxidation <strong>of</strong> carbon monoxide<br />
over Cu- and Ag-NaY catalysts with aqueous<br />
hydrogen peroxide. Mater. Research Bull. 42:<br />
2170-2183.<br />
[5] Haber, J., Wojciechowska, M., Ziel<strong>in</strong>ski, M.,<br />
Przystajko, W. 2007. Effect <strong>of</strong> MgF2 and<br />
Al2O3 supports on the structure and catalytic<br />
activity <strong>of</strong> copper-manganese oxide catalysts.<br />
Catal. Lett. 113: 46-53.<br />
[6] Jeyakumar, K., Chand, D.K. 2006. Copper<br />
perchlorate: Efficient acetylation catalyst<br />
under solvent free conditions. J. Mol. Catal. A:<br />
Chem. 255: 275-282.<br />
[7] Kadgaonkar, M.D., Laha, S.C., Pandey, R.K.,<br />
Kumar, P., Mirajkar, S.P., Kumar, R. 2004.<br />
Cerium-conta<strong>in</strong><strong>in</strong>g MCM-41 materials as<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
selective acylation and alkylation catalysts.<br />
Catal. Today. 97: 225-231.<br />
[8] Olah, G.A. 1973. Friedel-Crafts Chemistry.<br />
USA: John Wiley & Sons.<br />
[9] Padro, C.L., Apesteguia, C.R. 2005. Acylation<br />
<strong>of</strong> phenol on solids acids: <strong>Study</strong> <strong>of</strong> the<br />
deactivation mechanism. Catal. Today. 107-<br />
108: 258-265.<br />
[10] Rao, Y.V.S., Kulkarni, S.J., Subrahmanyam,<br />
M., Rao, A.V.R. 1995. An improved acylation<br />
<strong>of</strong> phenol over modified ZSM-5 catalysts.<br />
Appl. Catal. A: Gen. 133: L1-L6.<br />
[11] Rywak, A.A., Burlitch, J.M. 1996. Sol-gel<br />
synthesis <strong>of</strong> nanocrystall<strong>in</strong>e magnesium<br />
fluoride: Its use <strong>in</strong> the preparation <strong>of</strong> MgF2<br />
films and MgF2-SiO2 composites. Chem.<br />
Mater. 8: 60-67.<br />
[12] Velusamy, S., Borpuzari, S., Punniyamurthy,<br />
T. 2005. Cobalt(II)-catalyzed direct<br />
acetylation <strong>of</strong> alcohols with acetic acid.<br />
Tetrahedron. 61: 2011-2015.<br />
[13] Wang, Z., Liu, Q., Yu, J., Wu, T., Wang, G.<br />
2003. Surface structure and catalytic behavior<br />
<strong>of</strong> silica-supported copper catalysts prepared<br />
by impregnation and sol-gel methods. Appl.<br />
Catal. A: Gen. 239: 87-94.<br />
[14] Wojciechowska, M., Ziel<strong>in</strong>ski, M.,<br />
Malczewska, A., Przystajko, W., Pietrowski,<br />
M. 2006. Copper-cobalt oxide catalysts<br />
supported on MgF2 or Al2O3-their structure<br />
and catalytic performance. Appl. Catal. A:<br />
Gen. 298: 225-231.<br />
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<strong>The</strong> Relation between <strong>The</strong> First <strong>Step</strong> Hydrothermal Temperature and <strong>Zeolite</strong>s<br />
Distribution on Synthesis <strong>of</strong> <strong>Zeolite</strong> from Fly Ash<br />
Introduction<br />
Aulia Rochmah, Hamzah Fansuri<br />
Chemistry Department, Faculty <strong>of</strong> Mathematics and Natural Sciences<br />
Institut Teknologi Sepuluh November (<strong>ITS</strong>) Surabaya<br />
Keputih Sukolilo Surabaya, East Java, Indonesia<br />
Correspond<strong>in</strong>g Author: h.fansuri@chem.its.ac.id<br />
Abstract<br />
This research <strong>in</strong>vestigates the relation between the first step hydrothermal temperature on the<br />
synthesis <strong>of</strong> zeolite from fly ash and the zeolite distribution. <strong>The</strong> zeolite quantities were<br />
calculated by Quantitative X-Ray Powder Diffractions (QXRPD) us<strong>in</strong>g Rietveld ref<strong>in</strong>ement<br />
method supported by XRF and Cation Exchange Capacity (CEC) data. Different compositions<br />
<strong>of</strong> three mixed zeolite phases, i.e K-Chabazite, K-Phillipsite, and K-F, were formed at different<br />
first step hydrothermal temperature, i.e 100, 120, 150 and 180 o C, and second hydrothermal<br />
reaction at 100 o C for 6 to 96 hrs on synthesis <strong>of</strong> zeolite from fly ash. <strong>The</strong> differences between<br />
calculated weight percentage <strong>of</strong> oxide <strong>of</strong> zeolites XRF data was due to the existences <strong>of</strong> oxides<br />
<strong>in</strong> unidentified phases and amorphous phases. <strong>The</strong> differences between calculated CEC and<br />
experiment were caused by exchangeable cations <strong>of</strong> other phases. It was found that zeolite<br />
crystallization time was shorter when the first step hydrothermal temperature was higher.<br />
Keywords: <strong>Zeolite</strong> synthesis, <strong>Zeolite</strong> from fly ash, Quantitative XRD<br />
Fly ash is one <strong>of</strong> the solid wastes generated <strong>in</strong> coal fired<br />
power stations which has harmful effect on<br />
environment. One <strong>of</strong> the environmental friendly efforts<br />
<strong>of</strong> fly ash utilizations is fly ash conversion <strong>in</strong>to zeolite<br />
materials. Many methods <strong>of</strong> zeolite synthesis from fly<br />
ash hydrothermally has been explored, i. e direct<br />
conversion [14, 15, 16], fusion methods [2, 4, 17], and<br />
extraction methods [6, 8]. Direct zeolite synthesis<br />
procedures have shorter stages then <strong>in</strong>direct conversion<br />
such as fusion and extraction methods. Although the<br />
direct conversion produce lower purity then those two<br />
methods, the zeolite products have reasonably high<br />
cation exchange capacity (CEC) (175 meq/100 g<br />
zeolites [14]). Thus, for lower grade zeolite such as<br />
fertilizers, the zeolite synthesis from fly ash by direct<br />
conversion is still feasible.<br />
<strong>Zeolite</strong> synthesis from fly ash by direct<br />
conversion has been conducted before by Muasyaroh et<br />
al. [13] hydrothermally us<strong>in</strong>g potassium hydroxide as<br />
alkali sources. More than one type zeolites was<br />
obta<strong>in</strong>ed, i.e K-Chabazite, K-Phillipsite, and K-F [13].<br />
However, the zeolite quantities have not been<br />
determ<strong>in</strong>ed, then it is not known the relation between<br />
the reaction conditions and zeolite formed distributions.<br />
It was reported that step-change <strong>of</strong> synthesis<br />
temperature dur<strong>in</strong>g hydrothermal treatment reduce by<br />
half <strong>of</strong> the total synthesis time [9]. Moreover,<br />
Muasyaroh et al. [13] also showed that higher first step<br />
hydrothermal temperature could improve dissolution <strong>of</strong><br />
silica and alum<strong>in</strong>a <strong>in</strong> fly ash and shorten the zeolite<br />
crystallization time.<br />
<strong>The</strong> aims <strong>of</strong> the present work were to explore<br />
the relation between the first step hydrothermal<br />
temperature and zeolite formed distributions, <strong>in</strong> order to<br />
provide another method for synthesis certa<strong>in</strong> zeolite<br />
type from fly ash with specific properties.<br />
Materials and Methods<br />
Experimental<br />
<strong>Zeolite</strong> materials was obta<strong>in</strong>ed from Muasyaroh, et al.<br />
[13] that were synthesized from fly ash us<strong>in</strong>g variation<br />
<strong>of</strong> first step hydrothermal temperature at 100, 120, 150,<br />
and 180 0 C for 3,5 hours then cont<strong>in</strong>ued by second<br />
hydrothermal temperature at 100 o C for 6, 24, 48, and 96<br />
hours.<br />
<strong>The</strong> zeolites were characterized by XRD, XRF<br />
and CEC determ<strong>in</strong>ations. XRD analysis was carried out<br />
by add<strong>in</strong>g 20% <strong>in</strong>ternal standard <strong>of</strong> Rutile to samples<br />
that conta<strong>in</strong> zeolite phases. <strong>The</strong> diffractograms obta<strong>in</strong>ed<br />
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was analyzed quantitatively by Rietveld ref<strong>in</strong>ements<br />
method us<strong>in</strong>g RIETICA s<strong>of</strong>tware. <strong>The</strong> chemical<br />
composition was measured us<strong>in</strong>g XRF and the CEC was<br />
determ<strong>in</strong>ed by ammonium acetate methods.<br />
Results and Discussion<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
Diffractogram <strong>of</strong> samples were analyzed qualitatively<br />
us<strong>in</strong>g X’Pert Grafic and Identify S<strong>of</strong>tware. Table 1<br />
shows the identified phases found as a result <strong>of</strong><br />
variations on the first step hydrothermal temperature i.e<br />
Mullite (PDF 15-0776), Quartz (PDF 05-0490),<br />
Hercynite (PDF 34-0192), Magnetite (PDF 02-1035),<br />
Kaliophilite (PDF 11-0313), K-Chabazite (PDF 44-<br />
0250), K-Phillipsite (PDF 16-0715), K-F (PDF 25-<br />
0619), Kalsilite (PDF 33-0988).<br />
Table 1. Identified Phases <strong>of</strong> zeolite products<br />
No. Samples<br />
T First <strong>Step</strong> Hydrothermal<br />
( o C)<br />
t Second <strong>Step</strong><br />
Hydrothermal (h)<br />
Phases<br />
1. M1a 100 6 Ml, Q, H, Mt<br />
2. M1b 100 24 Ml, Q, H, Mt<br />
3. M1c 100 48 Ml, Q, H, Mt<br />
4. M1d 100 96 K-Cha, K-F, K-Phi, Ml, Q, H, Mt<br />
5. M2a 120 6 Ml, Q, H, Mt<br />
6. M2b 120 24 Ml, Q, H, Mt<br />
7. M2c 120 48 K-Cha, K-F, K-Phi, Ml, Q, H, Mt<br />
8. M2d 120 96 K-Cha, K-F, K-Phi, Ml, Q, Mt<br />
9. M3a 150 6 Ml, Q, H, Mt<br />
10. M3b 150 24 Ml, Q, H, Mt<br />
11. M3c 150 48 K-Cha, K-F, K-Phi, Ml, Q, H, Mt<br />
12. M3d 150 96 K-Cha, K-F, K-Phi, Ml, Q, H, Mt<br />
13. M4a 180 6 Ml, Q, H, Mt<br />
14. M4b 180 24 K-Cha, K-F, K-Phi, Ml, Q, Mt<br />
15. M4c 180 48 K-Cha, K-F, K-Phi, Ml, Q,H, Mt<br />
16. M4d 180 96 K-Cha, K-F, K-Phi, Ml, Q, Mt<br />
Mul=Mullite, Q=Quartz, H=Hercynite, Mag=Magnetite, K-Cha=K-Chabazite, K-F= K-F,<br />
K-Phi=K-Phillipsite<br />
Figure 1 <strong>Zeolite</strong> distribution at variation <strong>of</strong> first<br />
step hydrothermal temperature 100, 120,<br />
150 and 180 o C: (a) K-Chabazite, (b) K-<br />
Phillipsite, and (c) K-F. ∆= 100 o C; □ =<br />
120 o C; ● = 150 o C; x = 180 o C.<br />
Types <strong>of</strong> zeolite from fly ash product similar<br />
to zeolite that produced by Juan et al. (2007) at<br />
variation <strong>of</strong> hydrothermal temperature. <strong>The</strong><br />
distribution is shown <strong>in</strong> Fig. 1. K-Chabazite<br />
distribution can be seen at Fig. 1(a). At 100 o C, K-<br />
Chabazite formed after second hydrothermal time 48<br />
hs. At 120 o C and 150 o C, this type zeolite formed<br />
after 24 hs, but at 120 o C its compositions decreased<br />
after 48 hs, while at 150 o C, its <strong>in</strong>creased. At 180 o C,<br />
K-Chabazite formed between 6 and 96 hs. <strong>The</strong> zeolite<br />
compositions changes as shown at Fig. 1 due to phase<br />
transformation <strong>of</strong> K-Chabazite phase <strong>in</strong>to another<br />
phase such as, K-Phillipsite and K-F. Distribution <strong>of</strong><br />
K-Phillipsite and K-F shown at Fig.1(a) and 1(c).<br />
K-Phillipsite not formed until second<br />
hydrothermal time 96 hs at 100 o C as shown at Fig.<br />
1(b). At 120 o C and 150 o C, K-Phillipsite formed after<br />
24 hs and its compositions <strong>in</strong>creased until 96 hs. At<br />
180 o C, K-Phillipsite formed after 6 hs and its<br />
compositions <strong>in</strong>creased until 48 hs, but after 48 hs its<br />
decreased. <strong>The</strong> K-Phillipsite compositions decl<strong>in</strong>e<br />
could be caused by redissolution <strong>of</strong> zeolite crystals<br />
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and turn <strong>in</strong>to another phase, such as K-F zeolite as<br />
shown at Fig. 1 (c).<br />
Fig. 1(c) described K-F zeolite distributions.<br />
At 100 o C, K-F formed after second hydrothermal<br />
temperature 48 hs. At 120 o C, 150 o C and 180 o C, K-F<br />
formed after 24 hs and until 96 hs their compositions<br />
<strong>in</strong>creased, but after 48 hs K-F compositions at 180 o C<br />
was the highest then its compositions at 120 o C and<br />
150 o C.<br />
Variation <strong>of</strong> first step hydrothermal<br />
temperature as shown at Fig. 1 <strong>in</strong>dicates a trend <strong>of</strong><br />
higher first step hydrothermal temperature shorter<br />
zeolite crystallisation time. First step hydrothermal<br />
process was process <strong>of</strong> dissolution <strong>of</strong> silicate,<br />
alum<strong>in</strong>ate and alum<strong>in</strong>osilicate species <strong>in</strong> fly ash.<br />
Temperature <strong>in</strong>fluence <strong>in</strong> dissolution process based<br />
on Kamali, et al. reports shows that Si concentration<br />
<strong>in</strong> filtrate <strong>in</strong>crease as temperature <strong>in</strong>crease. While<br />
Catalfamo, et al. (<strong>in</strong> Mol<strong>in</strong>a and Poole [12]) reported<br />
that dissolution rate <strong>of</strong> alum<strong>in</strong>um goes faster than<br />
Silicon dissolution at beg<strong>in</strong>n<strong>in</strong>g <strong>of</strong> the process and its<br />
concentration tends to <strong>in</strong>crease as the temperature<br />
<strong>in</strong>crease. <strong>The</strong> higher silicate, alum<strong>in</strong>ate, and<br />
alum<strong>in</strong>osilicate concentrations <strong>in</strong> solution, the shorter<br />
zeolite crystallisation rate. Bo and Hongzhu [3]<br />
reported that higher temperature can promote<br />
dissolution <strong>of</strong> the solid phase <strong>in</strong> the zeogel and<br />
<strong>in</strong>creases the concentration <strong>of</strong> the solution, thus<br />
accelerat<strong>in</strong>g the formation <strong>of</strong> larger crystals and<br />
decreas<strong>in</strong>g the crystallization time. <strong>The</strong> temperature<br />
was the ma<strong>in</strong> factor that affect<strong>in</strong>g the type <strong>of</strong><br />
synthesized zeolite with KOH [10]. By apply<strong>in</strong>g<br />
temperature <strong>in</strong> particular time <strong>in</strong>tervals, one type <strong>of</strong><br />
zeolite phase transformed <strong>in</strong>to another phase that<br />
more stable, as the Ostwald_s rule; the first<br />
polymorph <strong>of</strong> a compound formed from solution is<br />
the least thermodynamically stable and is then<br />
replaced <strong>in</strong> succession by more thermodynamically<br />
stable polymorphs [1]. <strong>The</strong> changes <strong>of</strong> zeolite type at<br />
variation <strong>of</strong> first step hydrothermal temperature<br />
shown at Fig. 2.<br />
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Figure 2 <strong>The</strong> Changes <strong>of</strong> <strong>Zeolite</strong> Type at<br />
Variation <strong>of</strong> First <strong>Step</strong> Hydrothermal<br />
Temperature: a) 100 o C, b) 120 o C, c)<br />
150 o C, and d) 180 o C.<br />
• = K-Chabazite; ○ = K-Phillipsite, and *<br />
= K-F.<br />
<strong>The</strong> formed zeolites at 100 o C were K-<br />
Chabazite, K-Phillipsite, and K-F that formed<br />
together after 48 hs. K-Chabazite at second<br />
hydrothermal time 96 hs have highest composition<br />
compared to K-Phillipsite and K-F compositions. At<br />
120 o C, K-Chabazite, K-Phillipsite, and K-F were<br />
formed together. Although those three zeolite types<br />
formed togheter, but after 24 hs K-Phillipsite and K-F<br />
compositions <strong>in</strong>creased as second hydrothermal time<br />
<strong>in</strong>creased. K-Chabazite compositions also <strong>in</strong>creased<br />
after 24 hs but its compositions decreased after 48 hs.<br />
At 150 o C, K-Chabazite, K-Phillipsite, and K-F also<br />
formed together after 48 hs, but at 96 hs K-Chabazite<br />
compositions were the highest <strong>of</strong> all zeolites. At 180<br />
o C after 6 hs, the three zeolite types, i. e K-Chabazite,<br />
K-Phillipsite, and K-F formed together, but after 48<br />
hs K-Chabazite and K-Phillipsite compositions<br />
decreased while K-F compositions <strong>in</strong>creased.<br />
<strong>The</strong> variation <strong>of</strong> first step hydrothermal<br />
temperature on zeolite synthesis from fly ash obta<strong>in</strong>ed<br />
mixed three zeolite types, which there were<br />
composition changes among formed zeolite phases.<br />
<strong>The</strong>se due to the zeolites may undergo different k<strong>in</strong>ds<br />
<strong>of</strong> structural changes <strong>in</strong>clud<strong>in</strong>g [5] : (i) cell volume<br />
contraction due to the removal <strong>of</strong> water and/or<br />
templat<strong>in</strong>g organic molecules (dehydration and<br />
calc<strong>in</strong>ation); (ii) displacive or reconstructive phase<br />
transformation(s) to more or less metastable phase(s);<br />
(iii) break<strong>in</strong>g (and new formation) <strong>of</strong> T–O–T bonds;<br />
(iv) negative thermal expansion (NTE); (v) structural<br />
collapse; (vi) structural breakdown (i.e. complete<br />
amorphization or recrystallization). Beside <strong>of</strong><br />
structural changes, the formation <strong>of</strong> mixed several<br />
zeolite types due to the zeolites synthesized from fly<br />
ash by direct conversion methods. <strong>Zeolite</strong> that<br />
synthesized from fly ash by <strong>in</strong>direct conversion, such<br />
as fusion methods or extractions could obta<strong>in</strong> s<strong>in</strong>gle<br />
phase zeolites [4,8].<br />
Chemical compositions <strong>of</strong> zeolite from fly<br />
ash were obta<strong>in</strong>ed from XRF measurement on sample<br />
M4b and M4d as shown at Table 2. Chemical<br />
compositions <strong>of</strong> zeolite from XRF analysis were<br />
compared to calculated chemical composition from<br />
quantitative XRD analysis.<br />
Table 2 Chemical Compositions <strong>of</strong> Sample M4b and<br />
M4d from XRF Analysis<br />
% Weights<br />
Components<br />
M4b M4d<br />
Al2O3 29,20 26,70<br />
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SiO2 36,00 32,50<br />
K2O 15,10 26,88<br />
Fe2O3 12,83 9,99<br />
Al2O3 could be found <strong>in</strong> Mullite, Hercynite,<br />
K-Chabazite, K-Phillipsite, and K-F. SiO2 could be<br />
found <strong>in</strong> Mullite, Quartz, Hercynite, K-Chabazite, K-<br />
Phillipsite, and K-F. K2O could be found <strong>in</strong> K-<br />
Table 3 M<strong>in</strong>eral Compositions <strong>of</strong> Sample M4b and M4d<br />
M<strong>in</strong>eral Phases Compositions (%)<br />
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Chabazite, K-Phillipsite and K-F. Fe2O3 could be<br />
found <strong>in</strong> Hercynite and Magnetite. <strong>The</strong> weight<br />
percentage <strong>of</strong> those oxides was proportional to the<br />
weight percentage <strong>of</strong> phases that conta<strong>in</strong> those oxides.<br />
Thus, the chemical compositions could expla<strong>in</strong> the<br />
zeolite quantities.<br />
M4b M4d<br />
Quartz (SiO 2) 3,37 0,53<br />
Mullite (Al 6Si 2O 13) 10,02 3,72<br />
Magnetite (Fe 3O 4) 7,65 6,55<br />
Hercynite (FeAl 2O 4) 0,02 0,00<br />
K-Chabazite (K 12(Al 11Si 25O 72).40H 2O) 22,97 0,39<br />
K-Phillipsite (K10(Al 10Si 22O 64).20H 2O) 1,26 0,57<br />
K-F (K 10(Al 10Si 10O 40).8H 2O) 0,73 30,77<br />
Amorphous 53,98 57,47<br />
Based on Table 3, SiO2 contents <strong>in</strong> sample<br />
M4b were 17,39% and <strong>in</strong> sample M4d were 12,74 %.<br />
Al2O3 contents <strong>in</strong> sample M4b were 23,05 % and <strong>in</strong><br />
sampel M4d were 23,89 %. K2O contents <strong>in</strong> sample<br />
M4b were 8,77 %, while <strong>in</strong> sample M4d were 20,50<br />
%. Fe2O3 contents <strong>in</strong> sample M4b were 15,29 % and<br />
<strong>in</strong> sample M4d were 13,08 %.<br />
SiO2, Al2O3, K2O, and Fe2O3 contents <strong>in</strong><br />
sample M4b and M4d <strong>in</strong> Table 3 different from XRF<br />
results <strong>in</strong> Table 2. <strong>The</strong>se due to the existence <strong>of</strong> SiO2,<br />
Samples<br />
Al2O3, K2O, and Fe2O3 that conta<strong>in</strong>ed <strong>in</strong> unidentified<br />
phases by XRD methods. Besides, those oxides could<br />
be <strong>in</strong> amorphous phases that have high contents, i. e<br />
53,98 % <strong>in</strong> sample M4b and 57,47 % <strong>in</strong> sample M4d.<br />
CEC measurement <strong>of</strong> zeolite from fly ash<br />
was conducted only to sample M1d, M2d, and M4d<br />
because <strong>of</strong> sample availability. <strong>Zeolite</strong> phase<br />
compositions calculated and measured CEC results<br />
shown <strong>in</strong> Table 4.<br />
Table 4 <strong>Zeolite</strong> Phase Compositions, Calculated and Measured CEC Results.<br />
<strong>Zeolite</strong> Phase Compositions (%)<br />
K-Cha K-Phi K-F<br />
Calculated CEC (meq/g) Measured CEC (meq/g)<br />
M1d 47,40 0,03 1,24 1,778 2,304<br />
M2d 2,90 3,33 19,44 1,360 2,509<br />
M4d 0,39 0,57 30,77 1,819 3,091<br />
<strong>The</strong> differences between calculated and<br />
measured CEC might be caused by the existence <strong>of</strong><br />
nonzeolitic phases that have ability to exchange<br />
cations. Those phases may be conta<strong>in</strong>ed <strong>in</strong><br />
unconverted phases <strong>of</strong> fly ash. Hidayati, et al.[7]<br />
reported that CEC measured <strong>of</strong> the fly ash were 4,46<br />
meq/100 g fly ashes. This result <strong>in</strong>dicates that there<br />
are phases <strong>in</strong> fly ash that able to exchange cations.<br />
Conclusions<br />
From the discussions above, it is concluded that the<br />
higher the first step hydrothermal temperature on<br />
synthesis <strong>of</strong> zeolite from fly ash, the shorter the<br />
second hydrothermal reaction needed for zeolite<br />
crystallisation. Different compositions <strong>of</strong> three mixed<br />
zeolite phases, i.e K-Chabazite, K-Phillipsite, and K-<br />
F formed at variation <strong>of</strong> first hydrothermal<br />
temperature (100, 120, 150 and 180 o C) dur<strong>in</strong>g second<br />
hydrothermal time 6-96 hs on synthesis <strong>of</strong> zeolite<br />
from fly ash.<br />
Calculated weight percentage <strong>of</strong> oxide <strong>of</strong><br />
zeolites <strong>in</strong> this study different from XRF result due to<br />
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the existences <strong>of</strong> oxides <strong>in</strong> unidentified phases and<br />
amorphous phases, then could not be quantified by<br />
Rietveld method. <strong>The</strong> differences between calculated<br />
CEC and experiment were caused by exchangeable<br />
cations <strong>of</strong> nonzeolitic and amorphous phases.<br />
Acknowledgements<br />
<strong>The</strong> authors would like to thank Mr. Sum<strong>in</strong>ar Pratapa<br />
from Physics Department, <strong>ITS</strong> Surabaya for his help<br />
on part <strong>of</strong> the XRD data collection and analyses.<br />
Fund<strong>in</strong>g for this research was provided by grant from<br />
<strong>The</strong> M<strong>in</strong>istry <strong>of</strong> Research and Technology, Republic<br />
<strong>of</strong> Indonesia.<br />
References<br />
[1] Barrer, R. M. 1982. Hydrothermal chemsitry <strong>of</strong><br />
zeolites. London: Academic Press.<br />
[2] Berkgaut, V.& S<strong>in</strong>ger, A. 1996. High capacity<br />
cation exchanger by hydrothermal<br />
zeolitization <strong>of</strong> coal fly ash. Applied Clay<br />
Science 10: 369-378.<br />
[3] Bo, W. & Hongzhu, M. 1998. Factors affect<strong>in</strong>g<br />
the synthesis <strong>of</strong> microsized NaY zeolite.<br />
Microporous and Mesoporous Materials 25:<br />
131–136.<br />
[4] Chang, H., & Shih, W. 1998. Conversion <strong>of</strong> fly<br />
ash <strong>in</strong>to zeolites for ion-exchange<br />
applications. Materials Letters 28: 263-268.<br />
[5] Cruciani, G. 2006. <strong>Zeolite</strong>s upon heat<strong>in</strong>g: factors<br />
govern<strong>in</strong>g their thermal stability and<br />
structural changes. Journal <strong>of</strong> Physics and<br />
Chemistry <strong>of</strong> Solids 67: 1973–1994.<br />
[6] El-Naggar, M.R., El-Kamash, A.M., El-Dessouky,<br />
M.I., Ghonaim A.K. 2008. Two-step method<br />
for preparation <strong>of</strong> Na-X zeolite blend from<br />
fly ash for removal <strong>of</strong> Cesium ions. Journal<br />
<strong>of</strong> Hazardous Materials 154: 963–972.<br />
[7] Hidayati, R.H. 2008. S<strong>in</strong>tesis zeolit dari abu<br />
layang batubara: kajian pengaruh waktu<br />
hidrotermal awal terhadap pembentukan<br />
zeolit. Tesis tidak diterbitkan Institut<br />
Teknologi Sepuluh November Surabaya.<br />
[8] Hollman, G.G., Steenbruggen, Janssen-<br />
Jurkovicvova M. 1999. A two-step process<br />
for the synthesis <strong>of</strong> zeolites from coal fly<br />
ash. Fuel 78: 1225–1230.<br />
[9] Hui, K.S. & Chao, C.Y.H. 2006. Effects <strong>of</strong> stepchange<br />
<strong>of</strong> synthesis temperature on synthesis<br />
<strong>of</strong> zeolite 4A from coal fly ash. Microporous<br />
and Mesoporous Materials 881: 45–151.<br />
[10] Juan, R., Hernandez, S., Andres, J. M., Ruiz, C.<br />
2007. Synthesis <strong>of</strong> granular zeolitic materials<br />
with high cation exchange capacity from<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
agglomerated coal fly ash. Fuel 86:1811–<br />
1821.<br />
[11] Kamali, M., Vaezifar, S., Kolahduzan, H.,<br />
Malekpour, A., Abdi, M. R. 2008. Synthesis<br />
<strong>of</strong> nanozeolite a from natural cl<strong>in</strong>optilolite<br />
and alum<strong>in</strong>um sulfate: optimization <strong>of</strong> the<br />
method. Powder Technology, Article <strong>in</strong><br />
Press.<br />
[12] Mol<strong>in</strong>a, A. & Poole, C. 2004. A comparative<br />
study us<strong>in</strong>g two methods to produce zeolites<br />
from fly ash. M<strong>in</strong>erals Eng<strong>in</strong>eer<strong>in</strong>g 17: 167–<br />
173.<br />
[13] Muasyaroh, D., Prasetyoko, D., Fansuri, H.<br />
2007. Pengaruh waktu hidrotermal terhadap<br />
pembentukan zeolit dari fly ash batu bara.<br />
Prosid<strong>in</strong>g, Sem<strong>in</strong>ar Nasional Kimia Jurusan<br />
Pendidikan Kimia FMIPA Universitas<br />
Negeri Yogyakarta, 17 November 2007.<br />
[14] Murayama, N., Takahashi, T., Shuku, K., Lee,<br />
H., Shibata, J. 2008. Effect <strong>of</strong> reaction<br />
temperature on hydrothermal syntheses <strong>of</strong><br />
potassium type zeolites from coal fly ash.<br />
Int. J. M<strong>in</strong>er. Process., Article <strong>in</strong> Press.<br />
[15] Querol, X., Alastuey, A. S., Lopez-Soler, A.,<br />
Plana, F. 1997. A fast method for recycl<strong>in</strong>g<br />
fly ash: microwave-assisted zeolite synthesis.<br />
Environ. Sci. Technol. 31: 2527-2533.<br />
[16] Querol, X., Uman’a, J.C., Plana F., Alastuey, A.,<br />
Lopez-Soler, A., Med<strong>in</strong>aceli, A., Valero, A.,<br />
Dom<strong>in</strong>go, M. J., Garcia-Rojo, E. 2001.<br />
Synthesis <strong>of</strong> zeolites from fly ash at pilot<br />
plant scale. example <strong>of</strong> potential<br />
applications. Fuel 80: 857-865.<br />
[17] Shigemoto, N., Hayashi, H., Miyaura, K. 1993.<br />
Selective formation <strong>of</strong> Na-X, zeolite from<br />
coal fly ash by fusion with sodium hydroxide<br />
prior to hydrothermal reaction. J. Mater. Sci.<br />
28: 4781– 4786.<br />
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NOx Adsorption with CuO Supported on NaY <strong>Zeolite</strong> from Rice Husk<br />
Introduction<br />
Chusnul Suraidah, Irm<strong>in</strong>a Kris Murwani *<br />
Chemistry Departement, Faculty <strong>of</strong> Mathematics and Natural Sciences<br />
Institut Teknologi Sepuluh Nopember<br />
Kampus <strong>ITS</strong> Sukolilo, Surabaya, Indonesia<br />
* e-mail : irm<strong>in</strong>a@chem.its.ac.id<br />
Abstract<br />
NO x adsorption has been studied on NaY zeolite and CuO (5, 10 and 15% wt) supported on NaY zeolite<br />
(CuO/NaY) from rice husk. NaY and CuO/NaY were characterized us<strong>in</strong>g XRD, FT-IR and spesific<br />
surface area were determ<strong>in</strong>ed by methylene blue method. <strong>The</strong> spesific surface area <strong>of</strong> NaY, 5% CuO/NaY,<br />
10% CuO/NaY and 15% CuO/NaY are 8,130; 8,127; 8,124 and 8,121 m 2 /g respectively. After adsorption,<br />
the NO x concentration on adsorbent was determ<strong>in</strong>ed by colorimetry method. Adsorptivity <strong>of</strong> NO x<br />
adsorbent from higher to lower are 5% CuO/NaY > 10% CuO/NaY > 15% CuO/NaY > NaY. This result<br />
are proportional with spesific surface area and reverse with adsorbent acidity for CuO/NaY zeolite.<br />
Adsorptivity was <strong>in</strong>fluenced by active adsorbent sites.<br />
Keywords: NaY and CuO/NaY synthesis, NO x adsorption, colorimetry.<br />
Experiment about nitrogen oxides (NOx) has been<br />
studied before because NOx are important family <strong>of</strong><br />
air pollut<strong>in</strong>g chemical. NOx sources produced from<br />
chemistry reaction, combustion, automobiles and<br />
<strong>in</strong>dustrial. NOx are extremely toxic, it can made<br />
ozone <strong>in</strong> the air, lung diseases such asthma and acid<br />
ra<strong>in</strong> [15]. Adsorption pr<strong>in</strong>ciple can used to solve this<br />
problem, adsorbent was used to NOx adsorption. NOx<br />
adsorption with zeolite and Al2O3 adsorbent has been<br />
studied before [1,2,12]. <strong>Zeolite</strong> synthesis has been<br />
done from rice husk as silica source [10].<br />
Hydrothermal method was used to NaY zeolite<br />
synthesis with comparison specific composition [13].<br />
High sillica content (94-96%) <strong>in</strong> rice husk to enable<br />
zeolite was synthezed from this material [6,17]. Ba,<br />
Pt and MnO2 supported on NaY zeolite was used as<br />
adsorbent, present metal load<strong>in</strong>g <strong>in</strong> zeolite shown<br />
adsorptivity zeolite <strong>in</strong>crease [1,5,9].<br />
Indonesia as producer rice plant yield rice husk<br />
garbage, for that reason benefit <strong>of</strong> rice husk must be<br />
look<strong>in</strong>g. High silica content <strong>in</strong> rice husk can used as<br />
silica precursor <strong>in</strong> zeolite synthesis that used as<br />
adsorbent. On the other hand, <strong>in</strong>creas<strong>in</strong>gly <strong>in</strong>dustrial<br />
and automobiles make NOx emission <strong>in</strong>crease. Based<br />
on two problem above, experiment zeolite synthesis<br />
from rice husk must be done and than zeolite used as<br />
NOx adsorbent. Metal supported on zeolite can<br />
<strong>in</strong>crease adsorptivity, so that CuO supported on<br />
zeolite NaY from rice husk must be studied too.<br />
Thus, rice husk garbage was hoped useful and NOx<br />
can reducible.<br />
Materials and Methods<br />
Preparation Adsorbent<br />
In this research, SiO2 precursor for synthesis <strong>of</strong> NaY<br />
was taked from rice husk. NaY zeolite synthesis was<br />
performed accord<strong>in</strong>g to composition <strong>of</strong> 10 Na2O :<br />
Al2O3 : 15 SiO2 : 300 H2O (molar ratio). <strong>The</strong> <strong>in</strong>itial<br />
precursor was prepared by mix<strong>in</strong>g alum<strong>in</strong>ate gel and<br />
silicate gel. After that, the mixture was heated <strong>in</strong> an<br />
oven at 100ºC for 24 hour. Subsequenly, the solid<br />
product was separated by filtration, washed and dried<br />
for overnight. CuO/NaY zeolite synthesis was<br />
prepared by <strong>in</strong>cipient wetness impregnation with CuO<br />
prosentage 5,10 and 15%. <strong>The</strong> mixture was dried at<br />
temperature 100ºC. <strong>The</strong> calc<strong>in</strong>ation <strong>of</strong> the prepared<br />
samples was performed <strong>in</strong> air at 400ºC for 4 hour.<br />
Characterization<br />
Adsorbent characterization was carried out by means<br />
<strong>of</strong> XRD and FTIR. XRD characterization was<br />
performed us<strong>in</strong>g XRD JEOL JDX – 3530 (Cu)<br />
equipment. FTIR characterisation was performed<br />
us<strong>in</strong>g FTIR Shimadzu – 8201 P equipment. <strong>The</strong><br />
specific surface area <strong>of</strong> adsorbent was determ<strong>in</strong>ed by<br />
methylene blue method. Adsorbent acidity was<br />
analysed by FT-IR after pyrid<strong>in</strong>e adsorption<br />
(pyrid<strong>in</strong>e-FTIR).<br />
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NOx adsorption test<br />
<strong>The</strong> adsorptivity <strong>of</strong> solids product NaY and<br />
CuO/NaY were tested by adsorption <strong>of</strong> NOx onto<br />
adsorbent samples, extraction <strong>of</strong> NOx from the<br />
occluded samples us<strong>in</strong>g a solvent, reduction <strong>of</strong><br />
nitrogen oxides to nitrite ions conta<strong>in</strong>ed <strong>in</strong> the extract<br />
us<strong>in</strong>g hydraz<strong>in</strong>e sulfate and detection and<br />
quantification <strong>of</strong> nitrogen oxides by colorization<br />
us<strong>in</strong>g a modified Griess reagent [8, 11].<br />
Results and Discussion<br />
<strong>The</strong> XRD pattern <strong>of</strong> NaY zeolite, shown <strong>in</strong> Fig. 1.<br />
<strong>The</strong> diffraction l<strong>in</strong>es characteristic <strong>of</strong> NaY at 2θ : 6,<br />
10, 12, 15 dan 24 [PPIT FAU (Powder Pattern<br />
Identification Tabel Faujasite)]. <strong>The</strong> framework IR<br />
spectra <strong>of</strong> NaY zeolite, shown <strong>in</strong> Fig. 2. <strong>The</strong> bands at<br />
about 3450 cm -1 was caused by vibrations <strong>of</strong> O-H and<br />
HO-H which are the consequence <strong>of</strong> the adsorption <strong>of</strong><br />
water. <strong>The</strong> presence <strong>of</strong> water was also evidenced by<br />
the H-O-H band at 1633 cm -1 . <strong>The</strong> bands at about<br />
1116 cm -1 , 955 cm -1 , 774 cm -1 , 714 cm -1 are due to<br />
symmetric and asymmetric stretch<strong>in</strong>g mode <strong>of</strong><br />
(Si,Al)O4 tetrahedra. <strong>The</strong> bands at about 574 cm -1 ,<br />
503 cm -1 are due to vibration related to external<br />
l<strong>in</strong>kages <strong>of</strong> double r<strong>in</strong>g polyhedra <strong>in</strong> the zeolite<br />
framework [7, 13, 16].<br />
CuO/NaY zeolite was synthezed by the <strong>in</strong>cipient<br />
wetness impregnation with 5, 10 and 15% <strong>of</strong> Cu<br />
load<strong>in</strong>gs. <strong>The</strong> XRD pattern <strong>of</strong> NaY and CuO/NaY,<br />
shown <strong>in</strong> Fig. 3. <strong>The</strong> XRD pattern <strong>of</strong> CuO/NaY show<br />
evidence <strong>of</strong> CuO phase at 2θ : 35; 38 dan 48 that<br />
labeled with (*) [3]. <strong>The</strong> framework IR spectra <strong>of</strong><br />
CuO/NaY zeolite, shown <strong>in</strong> Fig. 4. <strong>The</strong> bands at<br />
about 3450 cm -1 , 1633 cm -1 are caused by vibrations<br />
<strong>of</strong> O-H and HO-H, bend<strong>in</strong>g vibration <strong>of</strong> H-O-H,<br />
respectively. <strong>The</strong> bands at about 1116 cm -1 , 955 cm -1 ,<br />
774 cm -1 , 714 cm -1 , 574 cm -1 , 503 cm -1 are typical for<br />
NaY [7 13, 16]. <strong>The</strong> bands at about 1396 cm -1 , 567<br />
cm -1 dan 458 cm -1 due to CuO [3].<br />
Intensitas (cps)<br />
3000<br />
2000<br />
1000<br />
%T<br />
0<br />
90<br />
60<br />
30<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
10 20 30 40 50 60 70 80 90<br />
2 θ(°)<br />
Figure 1. XRD pattern <strong>of</strong> NaY zeolite<br />
OH<br />
4000 3000 2000 1000<br />
1/cm<br />
Figure 2. FT-IR spectra <strong>of</strong> NaY zeolite<br />
Intensitas (cps)<br />
∗<br />
∗<br />
∗<br />
HOH<br />
TO<br />
TO<br />
TO<br />
TO<br />
574<br />
503<br />
10 20 30 40 50 60 70 80 90<br />
2θ(°)<br />
Figure 3. XRD pattern <strong>of</strong> NaY (a) and CuO/NaY(b)<br />
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HO<br />
(d)<br />
(c)<br />
(b)<br />
(a)<br />
4000 3000 2000 1000<br />
1/cm<br />
HOH<br />
CuO<br />
T-O<br />
T-O<br />
T-O<br />
T-O<br />
CuO<br />
CuO<br />
Figure 4. FT-IR spectra <strong>of</strong> NaY (a) and CuO/NaY<br />
(5% CuO/NaY (b), 10% CuO/NaY (c), 15%<br />
CuO/NaY (d))<br />
Specific surface area measured by methylene blue<br />
method. Surface area <strong>of</strong> NaY, 15% CuO/NaY, 10%<br />
CuO/NaY and 5% CuO/NaY are 8,130; 8,121; 8,124<br />
and 8,127 m 2 /gram, respectively.<br />
FTIR spectra <strong>of</strong> pyrid<strong>in</strong>e adsorbed on NaY and (5,<br />
10 and 15%) CuO/NaY are shown <strong>in</strong> Fig. 5. <strong>The</strong><br />
vibration bands at about 1450 cm -1 , 1490 cm -1 and<br />
1610 cm -1 correspond to pyrid<strong>in</strong>e coord<strong>in</strong>ated on<br />
Lewis acid sites that labeled with (*) [14]. Adsorbent<br />
acidity from higher to lower are 15% CuO/NaY ><br />
10% CuO/NaY > 5% CuO/NaY > NaY.<br />
(a)<br />
(b)<br />
(c)<br />
(d)<br />
*<br />
*<br />
*<br />
1800 1700 1600 1500 1400 1300<br />
1/λ (cm -1 )<br />
Figure 5. FT-IR spectra <strong>of</strong> NaY (a) and CuO/NaY<br />
(5% CuO/NaY (b), 10% CuO/NaY (c), 15%<br />
CuO/NaY (d)) after pyrid<strong>in</strong>e adsorbed.<br />
<strong>The</strong> result <strong>of</strong> NOx adsorption test on NaY and (5,<br />
10, 15%) CuO/NaY adsorbent shown <strong>in</strong> Fig. 6.<br />
Adsorptivity <strong>of</strong> CuO/NaY zeolite was higher than<br />
NaY zeolite, it caused presence CuO <strong>in</strong> NaY zeolite.<br />
Adsorptivity <strong>of</strong> 5% CuO load<strong>in</strong>g was higher than<br />
15% CuO load<strong>in</strong>g. Adsorptivity decrease with<br />
<strong>in</strong>creas<strong>in</strong>gly CuO load<strong>in</strong>g on NaY zeolite, because<br />
CuO cover zeolite surface. This results are<br />
proportional with spesific surface area and reverse<br />
*<br />
*<br />
*<br />
*<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
with adsorbent acidity for CuO/NaY zeolite. NOx was<br />
adsorpted on cation, oxygen atoms and hydroxyl<br />
groups, that are active zeolite sites [1,2,4,9,12]. NOx<br />
adsorption on CuO/NaY zeolite was not <strong>in</strong>fluenced<br />
presence Cu 2+ because this cation has been<br />
surrounded by oxygen atoms. This <strong>in</strong>dicate that<br />
adsorptivity was <strong>in</strong>fluenced active adsorbent sites.<br />
NO x (mmol)<br />
0.4<br />
0.3<br />
0.2<br />
0.1<br />
0.0<br />
NaY 5% CuO/NaY 10% CuO/NaY 15% CuO/NaY<br />
Adsorbent<br />
Figure 6. NOx adsorption test on adsorbent NaY and<br />
CuO/NaY.<br />
Conclusion<br />
Adsorptivity <strong>of</strong> zeolite <strong>in</strong>crease after CuO<br />
supported on NaY zeolite. Adsorptivity <strong>of</strong> NOx<br />
adsorbent from higher to lower are 5% CuO/NaY ><br />
10% CuO/NaY > 15% CuO/NaY > NaY.<br />
Adsorptivity was <strong>in</strong>fluenced by active adsorbent sites<br />
and surface area, but was not <strong>in</strong>fluenced adsorbent<br />
acidity.<br />
Acknowledgements<br />
This reasearch was supported by Chemistry<br />
Departement, Faculty <strong>of</strong> Mathematics and Natural<br />
Sciences, Institut Teknologi Sepuluh Nopember<br />
Surabaya. <strong>The</strong> autors thanks LPPM <strong>ITS</strong> for their<br />
f<strong>in</strong>ancial support.<br />
References<br />
[1] Bentrup, Ursula., Angelika Brückner, Manfred<br />
Richter, Rolf Fricke, Applied Catalysis B:<br />
Environmental 32, (2001), 229–241.<br />
[2] Brosius, Roald., Kalle Arve, Marijke H.<br />
Groothaert, Johan A. Martens, Journal <strong>of</strong><br />
Catalysis 231, (2005), 344–353.<br />
[3] El-Bahy, Ze<strong>in</strong>hom Mohamed., Materials<br />
Research Bullet<strong>in</strong>, (2007).<br />
[4] Gil, Barbara., Karol<strong>in</strong>a Mierzyn´ska, Monika<br />
Szczerb<strong>in</strong>´ska, Jerzy Datka, Applied Catalysis<br />
A: General 319, (2007), 64–71.<br />
Proceed<strong>in</strong>g Book 533
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January 24, 2009<br />
[5] Goscianska, Joanna., Philippe Baz<strong>in</strong>, Olivier<br />
Marie, Marco Daturi, Izabela Sobczak, Maria<br />
Ziolek, Catalysis Today 119, (2007), 78–82.<br />
[6] Harsono, heru., Jurnal Ilmu Dasar vol. 3, No.<br />
2, (2002), 98-103.<br />
[7] Holmberg, Brett A., Huant<strong>in</strong>g Wang, Yushan<br />
Yan, Microporous and Mesoporous Materials<br />
74, (2004), 189–198.<br />
[8] Kil, Jeong Ki., In Sik Nam, Joo-Hyoung Park,<br />
Sang Jun Park, United States Patent<br />
Application Publication, US 2006/0024836<br />
A1, (2006).<br />
[9] Li, Gonghu., Conrad A. Jones, Vicki H.<br />
Grassian, Sarah C. Larsen, Journal <strong>of</strong> Catalysis<br />
234,(2005), 401–413.<br />
[10] Malek, Nik Ahmad Nizam Nik., Alias Mohd<br />
Yus<strong>of</strong>, <strong>The</strong> Malaysian Journal <strong>of</strong> Analytical<br />
Sciences, Vol 11, No 1, (2007), 76-83.<br />
[11] Park, Joo-Hyoung., M<strong>in</strong> S. H., Sang J. P., Sang<br />
j. P., et all, Journal <strong>of</strong> Catalysis 241, (2006),<br />
470-474.<br />
[12] Perdana, Indra, , Derek Creasera,, I. Made<br />
Bendiyasab, Rochmadib, BomaWikan Tyosob,<br />
Chemical Eng<strong>in</strong>eer<strong>in</strong>g Science 62, (2007),<br />
3882 – 3893.<br />
[13] Sang, Shiyun., Zhongm<strong>in</strong> Liu, Peng Tian, Ziyu<br />
Liu, Lihong Qu, Yangyang Zhang, Materials<br />
letters 60, (2006), 1131-1133.<br />
[14] Salama, Tarek M., Ayman H. Ahmed, Ze<strong>in</strong>hom<br />
M. El-Bahy, Microporous and Mesoporous<br />
Materials 89, (2006), 251–259.<br />
[15] Velsen, Daniel Van., Sulphur Dioxide and<br />
NitroOxides <strong>in</strong> ndustrial Waste Gases:<br />
Emission, Legislation and Abatement, Kluwer<br />
Academic Publishers, Netherlands, (1991).<br />
[16] Weitkamp, J., L. Puppe, Catalysis and <strong>Zeolite</strong>s<br />
Fundamental and Application, Spr<strong>in</strong>ger, New<br />
York, (1999).<br />
[17] Yalc<strong>in</strong>, N., V. Sev<strong>in</strong>c, Ceramic International 27,<br />
(2001), 219-224.<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
Proceed<strong>in</strong>g Book 534
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January 24, 2009<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
NOx Adsorption with Cr Supported on NaY <strong>Zeolite</strong> from Rice Husk<br />
Adhita Febriana and Irm<strong>in</strong>a Kris Murwani<br />
Chemistry <strong>Study</strong> Program, Faculty <strong>of</strong> Mathematics and Natural Sciences<br />
Sepuluh Nopember Institute <strong>of</strong> Technology Surabaya,<br />
Keputih Sukolilo, Surabaya, Indonesia, 60111.<br />
*Email : irm<strong>in</strong>a@chem.its.ac.id<br />
Abstract<br />
NO x adsorption with Cr supported on NaY zeolite from rice husk have been <strong>in</strong>vestigated. <strong>The</strong><br />
adsorbent used <strong>in</strong> this studied were NaY zeolite and Cr 2O 3/NaY that made from rice husk. Rice husk<br />
was used for precursor NaY zeolite because its has high content SiO 2 about 94 – 96%. Cr 2O 3/NaY<br />
(2,97 and 3,84 wt%) were synthesized by impregnation method. <strong>The</strong> adsorbents were characterized<br />
by XRD, FTIR, the specific surface areas was determ<strong>in</strong>ed by the methylene blue method and the<br />
acidity was carried out by pyrid<strong>in</strong>e – FTIR. <strong>The</strong> concentration <strong>of</strong> NO x gas was analyzed with<br />
colorimetric method. <strong>The</strong> adsorptivity for NO x gas decreased <strong>in</strong> the order Cr 2O 3/NaY 3,84% ><br />
Cr 2O 3/NaY 2,97% > zeolit NaY. <strong>The</strong> specific surface areas <strong>of</strong> NaY zeolite was 8,1301 m 2 /g,<br />
Cr 2O 3/NaY 2,97% was 8,1301 m 2 /g, and Cr 2O 3/NaY 3,84% was 8,1048 m 2 /g.<br />
Keywords: Adsorption NO x gas, NaY, Cr 2O 3/NaY, rice husk<br />
Introduction<br />
Generally, chemical reactions will produce side<br />
products that <strong>of</strong>ten become waste, where the waste<br />
will become a new problem because it will<br />
contam<strong>in</strong>ate the surround<strong>in</strong>g environment. One <strong>of</strong><br />
the side products <strong>of</strong> the chemical reaction is<br />
nitrogen oxide gas (NOx), which is one <strong>of</strong> the side<br />
products <strong>of</strong> the synthesis <strong>of</strong> picric acid. Generally,<br />
the NOx gas is a chemical compound derived from<br />
burn<strong>in</strong>g coal or petroleum, generated from the<br />
disposal automobile and mach<strong>in</strong>e. NOx gas is one<br />
<strong>of</strong> the air pollutant that is quite dangerous for the<br />
environment because the NOx gas can cause<br />
damage to people, such as emphysema and lung<br />
damage, and will also damage the ozone, which is a<br />
major cause <strong>of</strong> global warm<strong>in</strong>g and acid ra<strong>in</strong>.<br />
<strong>The</strong>refore, need to be a way to the NOx gas <strong>in</strong> the<br />
air can be reduce (Kil, 2006; Sakamoto, 2006).<br />
One way to reduce NOx gases <strong>in</strong> the air is<br />
adsorption the NOx gases with an adsorbent.<br />
Materials that can be used as adsorbent is Al2O3,<br />
MgF2, zeolite and many more other materials that<br />
can be used as adsorbent. Synthesis <strong>of</strong> zeolite has<br />
been done by many researchers on the previous<br />
<strong>in</strong>vestigation <strong>in</strong>clud<strong>in</strong>g Sang (2005), Malek (2007),<br />
and Gonghu Li (2005) by us<strong>in</strong>g several methods<br />
and comparison mol certa<strong>in</strong>. One way to get zeolite<br />
is from rice husk because SiO2 content on rice husk<br />
is high (94 - 96%) allows zeolite can be synthesis<br />
from these raw materials. <strong>Zeolite</strong> conta<strong>in</strong><strong>in</strong>g metal<br />
such as Mn, Mo, Pt, Pd and Ba have also been<br />
made by previous researchers, where load<strong>in</strong>g<br />
zeolite with metal shows the <strong>in</strong>fluence <strong>of</strong> <strong>in</strong>creas<strong>in</strong>g<br />
the capacity <strong>of</strong> adsorption.<br />
Rice is the ma<strong>in</strong> agricultural products <strong>in</strong> the<br />
agricultural countries, <strong>in</strong>clud<strong>in</strong>g Indonesia. This is<br />
because rice is one <strong>of</strong> the staple food <strong>in</strong> Indonesia.<br />
Rice husk is one <strong>of</strong> the side products <strong>of</strong> rice mill<strong>in</strong>g<br />
process, which until the current rice husk is waste<br />
that still has not been used optimally. Dur<strong>in</strong>g this<br />
rice husk is only used as a propellant brick or just<br />
casually discarded. Some research <strong>in</strong>dicates that<br />
rice husk ash have the silica content is high enough,<br />
where silica is one <strong>of</strong> the basic materials for<br />
synthesis <strong>of</strong> zeolite (Harsono, 2002; Malek, 2007).<br />
Dur<strong>in</strong>g this research about adsorption <strong>of</strong> NOx<br />
gas is very low, which zeolite used as support for<br />
adsorption <strong>of</strong> NOx gas. In order for the utilization<br />
<strong>of</strong> waste rice husk as a producer <strong>of</strong> silica for<br />
synthesis zeolite and <strong>in</strong> order to overcome the air<br />
pollution <strong>in</strong> the NOx gas, so need research on the<br />
NOx gases adsorption on zeolite NaY and<br />
Cr2O3/NaY made from rice husk. This research<br />
started from preparation source <strong>of</strong> silica from rice<br />
husk and synthesis zeolite NaY. <strong>The</strong>n zeolite NaY<br />
will impregnation with CrCl3·6H2O that will be<br />
obta<strong>in</strong>ed Cr2O3/NaY, where zeolite NaY and<br />
Cr2O3/NaY is then tested with XRD, FT-IR, with a<br />
surface area <strong>of</strong> the measurement method methylene<br />
blue and test the acidity with pyrid<strong>in</strong>e-FTIR. In<br />
addition, the test adsorption <strong>of</strong> zeolite NaY and<br />
Cr2O3/NaY will be done by conduct<strong>in</strong>g NOx gas at<br />
adsorbent and analyzed by colorimetric method to<br />
know the concentration <strong>of</strong> NOx gases.<br />
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Materials and Methods<br />
Preparation <strong>of</strong> adsorbents<br />
In this research, SiO2 precursor for synthesis <strong>of</strong><br />
NaY zeolite was taked from rice husk. Synthesis<br />
NaY zeolite was performed accord<strong>in</strong>g to the<br />
composition <strong>of</strong> 10 Na2O : Al2O3 : 15 SiO2 : 300<br />
H2O (molar ratio) [12]. <strong>The</strong> <strong>in</strong>itial precursor was<br />
prepared by mix<strong>in</strong>g the required amounts <strong>of</strong><br />
alum<strong>in</strong>at gel solution and silicate gel, stirred for<br />
two hours, and then heated at the temperatures <strong>of</strong><br />
100°C for 12 hours. <strong>The</strong> results <strong>of</strong> synthesis then<br />
filtered, washed, and dried <strong>in</strong> an oven at the<br />
temperatures <strong>of</strong> 100°C for 24 hours so it will be<br />
acquired zeolite NaY. <strong>The</strong> adsorbents <strong>of</strong> 2,97 and<br />
3,84 wt% Cr2O3/NaY were prepared by<br />
impregnation method us<strong>in</strong>g CrCl3·6H2O solution.<br />
<strong>The</strong> adsorbents were dried at 100°C for 24 hours<br />
and calc<strong>in</strong>ed <strong>in</strong> air at 400°C for 4 hours [14].<br />
Characterization<br />
Adsorbents characterization was carried out by<br />
means <strong>of</strong> XRD and FTIR. XRD characterization<br />
was performed us<strong>in</strong>g XRD JEOL JDX 3530 (Cu<br />
Kα) equipment. FTIR characterization was<br />
performed us<strong>in</strong>g Shimadzu FTIR 8400S equipment.<br />
Specific surface areas were determ<strong>in</strong>ed by<br />
methylene blue method. Lewis acid sites and<br />
Brønsted acid were analyzed by pyrid<strong>in</strong>e – FTIR.<br />
Adsorption <strong>of</strong> NOx Gas on <strong>Zeolite</strong> NaY and<br />
Cr2O3/NaY from Rice Husk<br />
Adsorption <strong>in</strong>volves the uptake NOx gas by the<br />
adsorbents. <strong>The</strong> tube conta<strong>in</strong>s about 20 mg <strong>of</strong><br />
adsorbent were placed <strong>in</strong> the reactor adsorption.<br />
<strong>The</strong> sample were activated by heat<strong>in</strong>g to 100°C and<br />
then NOx gas was adsorbed for 1 hour at room<br />
temperature. All the adsorbents were extracted at 5<br />
times. About 15 mL aquades was added to each<br />
adsorbents, and then sentrifuge for 15 m<strong>in</strong>utes. One<br />
mL CuSO4 solution, 1 mL hidraz<strong>in</strong>e sulphate<br />
solution and 2 mL sodium hydroxide solution were<br />
added per 1 mL <strong>of</strong> eluted solvent. Reduction was<br />
performed at 40°C for 15 m<strong>in</strong>utes, and then the<br />
chemical sensor was the Griess reagent, conta<strong>in</strong><strong>in</strong>g<br />
N-1-naphthylethylenediam<strong>in</strong>e dihydrochloride<br />
(NED) dissolved <strong>in</strong> 85% phosphate solution<br />
conta<strong>in</strong><strong>in</strong>g 1 g <strong>of</strong> sulphanyl amide, then diluted to<br />
100 mL was added. <strong>The</strong> changes color then<br />
measured with spectrophotometer on the<br />
wavelength 540 nm [2,4,9].<br />
Results and Discussion<br />
Synthesis <strong>of</strong> zeolite NaY beg<strong>in</strong>s with preparation<br />
<strong>of</strong> SiO2 obta<strong>in</strong>ed from rice husk ash. <strong>Zeolite</strong> NaY<br />
is synthesized from silicate gel and alum<strong>in</strong>at with<br />
the comparison 10 Na2O : Al2O3 : 15 SiO2 : 300<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
H2O (Sang, 2005). Synthesis <strong>of</strong> zeolite NaY will<br />
also be performed on hidrotermal assisted with the<br />
high temperatures with the water.<br />
<strong>The</strong> solvent <strong>of</strong> silicate gel and alum<strong>in</strong>at are<br />
mixed, and then <strong>in</strong>serted <strong>in</strong>to the reactor and<br />
heated at the temperatures <strong>of</strong> 100°C for 12 hours.<br />
After cold, the mixture is filtered and washed with<br />
aquades up to its neutral pH (Prasetyoko, 2005;<br />
Sang, 2006). <strong>The</strong> solid that have been obta<strong>in</strong>ed,<br />
then dried <strong>in</strong> the oven for 24 hours at the<br />
temperature <strong>of</strong> 100°C so it will be obta<strong>in</strong>ed powder<br />
<strong>of</strong> zeolite NaY is creamy. Powder <strong>of</strong> zeolite NaY<br />
is then characterized with XRD, as seen <strong>in</strong> the<br />
Figure 2.<br />
Intensitas (cps)<br />
Zeolit NaY<br />
PPIT<br />
20 40 60 80<br />
2θ (°)<br />
Figure 1. Pattern <strong>of</strong> Zeolit NaY<br />
Pattern <strong>of</strong> zeolite NaY showed the peak <strong>in</strong> the<br />
region 2θ about 6, 10, 12, 15 and 24º, which where<br />
area <strong>in</strong> the region 2θ about 6 º with the highest<br />
<strong>in</strong>tensity shows typical peak <strong>of</strong> zeolite NaY. This is<br />
<strong>in</strong> accordance with the peaks on the standard PPIT<br />
(Powder Pattern Identification Table), so this shows<br />
that the synthesis <strong>of</strong> zeolite NaY has been<br />
successful.<br />
In addition analyzed with XRD, zeolite NaY<br />
also analyzed by FTIR. In the figure 3, there is a<br />
peaks <strong>in</strong> the region 3,450 cm -1 shows the region <strong>of</strong><br />
O-H vibration stretch<strong>in</strong>g associated with water. At<br />
the peak <strong>of</strong> 1633 cm -1 shows the peak for H-O-H.<br />
Peak area <strong>in</strong> 1116 cm -1 shows the peak <strong>of</strong> TO4<br />
asimetri external l<strong>in</strong>kages vibration stretch<strong>in</strong>g (T =<br />
Si or Al) (Prasetyoko, 2005).<br />
T (%)<br />
O - H<br />
4000 3500 3000 2500<br />
1/cm<br />
2000 1500 1000 500<br />
Figure 2. Spectra FTIR <strong>of</strong> Zeolit NaY<br />
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H - O - H<br />
TO 4 eksternal<br />
TO 4 <strong>in</strong>ternal<br />
NaY<br />
T - O ulur<br />
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<strong>The</strong> First International Sem<strong>in</strong>ar on Science and Technology<br />
January 24, 2009<br />
At the peak <strong>of</strong> 955 cm -1 shows the region to<br />
TO4 tetrahedron asimetri <strong>in</strong>ternal vibration<br />
stretch<strong>in</strong>g (Liu, 2003) and can also <strong>in</strong>dicate areas<br />
vibration stretch<strong>in</strong>g (alum<strong>in</strong>o) <strong>of</strong> silicate and silica<br />
polimorfis. Peak <strong>in</strong> the 774 and 714 cm -1 is the<br />
peak symmetry vibration stretch<strong>in</strong>g T-O. Peak <strong>in</strong><br />
the 578 and 503 cm -1 which does not show sharp<br />
regional for a double r<strong>in</strong>g <strong>of</strong> the external l<strong>in</strong>kages<br />
related to the structure <strong>of</strong> the framework <strong>Zeolite</strong><br />
NaY (El - Bahy, 2007; Sang, 2006; Weitkamp,<br />
1999).<br />
After synthesis <strong>of</strong> zeolite NaY as supported<br />
have been successful, this research followed by<br />
metal load<strong>in</strong>g CrCl3·6H2O on supported zeolite<br />
NaY through impregnation. <strong>The</strong> impregnation<br />
method used is the <strong>in</strong>cipient wetness method.<br />
Impregnation will done by mixed the powder<br />
zeolite NaY <strong>in</strong> solution CrCl3·6H2O with a<br />
percentage load<strong>in</strong>g are 2.97 and 3.84%. Mixed <strong>in</strong><br />
the form <strong>of</strong> pulp is then dried at temperatures <strong>of</strong><br />
100°C for 24 hours and calc<strong>in</strong>ed at the<br />
temperatures <strong>of</strong> 400°C for four hours for activation<br />
adsorbent with the purpose to remove the solvent<br />
(Weitkamp, 1999). <strong>The</strong> powder are obta<strong>in</strong>ed after<br />
calc<strong>in</strong>ations are a bright yellow powder and then<br />
characterized with XRD. <strong>The</strong> pattern <strong>of</strong> the<br />
analysis as shown <strong>in</strong> figure 4.<br />
Intensitas (cps)<br />
♦♦<br />
♦ ♦<br />
∗<br />
♦<br />
♦<br />
∗<br />
∗<br />
Zeolit NaY<br />
Cr 2 O 3 /NaY<br />
20 40 60 80<br />
2θ (°)<br />
Cr 2 O 3<br />
Figure 3. Patterm <strong>of</strong> <strong>Zeolite</strong> NaY, Cr2O3/NaY and<br />
Cr2O3<br />
In the figure 4, the pattern <strong>of</strong> impregnation is<br />
not shows the significant changes <strong>of</strong> the pattern <strong>of</strong><br />
zeolite NaY. <strong>The</strong>re are differences <strong>in</strong> the <strong>in</strong>tensity<br />
both <strong>of</strong> the pattern where the <strong>in</strong>tensity <strong>of</strong><br />
Cr2O3/NaY (♦) is lower than zeolite NaY. This<br />
shows that zeolite NaY has been impregnated with<br />
Cr2O3, but because the percentage <strong>of</strong> load<strong>in</strong>g <strong>of</strong><br />
ion Cr 3+ is small, the peak <strong>of</strong> Cr2O3 (*) does not<br />
appear, but will only reduce the <strong>in</strong>tensity <strong>of</strong> the<br />
supported <strong>of</strong> zeolite NaY. From the pattern can<br />
also be known that impregnation is not damage the<br />
structure <strong>of</strong> supported zeolite NaY, although the<br />
<strong>in</strong>tensity is reduced when compared with pattern <strong>of</strong><br />
supported zeolite NaY. Cr2O3/NaY which has been<br />
obta<strong>in</strong>ed, besides characterized with XRD also<br />
analyzed by FTIR.<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
In the figure 4 shows that peak <strong>in</strong>tensity at<br />
3,492 cm -1 shows the region O-H vibration<br />
stretch<strong>in</strong>g associated with water. Peak at 1641 cm -1<br />
shows region <strong>of</strong> the H-O-H (Liu, 2003). Peak <strong>in</strong><br />
2071 cm -1 (ξ) shows the <strong>in</strong>tensity decreased from<br />
zeolite NaY > Cr2O3/NaY 2,97% > Cr2O3/NaY<br />
3,8%. This is because this area is a likely peak <strong>of</strong><br />
the T-O-H (T = Al or Si), where the H atoms <strong>in</strong> the<br />
T-O-H will be replaced with ion Cr 3+ , which are<br />
absorbed <strong>in</strong>to the <strong>Zeolite</strong> NaY when impregnation.<br />
Because not all H atoms can be replaced by ion<br />
Cr 3+ , the peak <strong>in</strong>tensity <strong>in</strong> the region <strong>in</strong> 2071 cm-1<br />
will not lost all.<br />
T (%)<br />
O - H<br />
a<br />
b<br />
c<br />
4000 3500 3000 2500 2000 1500 1000 500<br />
1/cm<br />
⌧<br />
⌧<br />
⌧<br />
H - O - H<br />
<br />
<br />
Figure 4. Spectra FTIR <strong>of</strong> (a) Zeolit NaY,<br />
(b) Cr2O3/NaY 2,97%, (c) Cr2O3/NaY<br />
3,84%<br />
Two peaks <strong>in</strong> 1478 and 1423 cm -1 on zeolite<br />
NaY ( ) after becom<strong>in</strong>g lost when zeolite NaY<br />
impregnation with Cr 3+ , but this peak can not be<br />
characterized. Peak area <strong>in</strong> 1179 cm -1 shows the<br />
structure <strong>of</strong> chromium where this is related to Cr5 +<br />
= O (Wojciechowska, 1995). At the peak <strong>of</strong> 797cm -<br />
1 shows the region to TO4 tetrahedron external<br />
symmetry vibration stretch<strong>in</strong>g (Liu, 2003) and can<br />
also <strong>in</strong>dicate areas vibration stretch<strong>in</strong>g <strong>of</strong><br />
tetrahedral symmetry SiO4 (Prasetyoko, 2005).<br />
Peak 955 cm -1 shows vibration stretch<strong>in</strong>g that TO4<br />
tetrahedron asimetri <strong>in</strong>ternal (Liu, 2003) and<br />
vibration stretch<strong>in</strong>g (alum<strong>in</strong>o) silicate and silica<br />
polimorfis.<br />
In this research, the specific surface area <strong>of</strong> the<br />
determ<strong>in</strong>ation made by us<strong>in</strong>g the methylene blue<br />
method. This method beg<strong>in</strong>s with the determ<strong>in</strong>ation<br />
<strong>of</strong> the maximum length <strong>of</strong> the wave and mak<strong>in</strong>g the<br />
calibration curve to know the concentration <strong>of</strong><br />
methylene blue absorbed by the sample so that the<br />
specific surface area <strong>of</strong> each sample can be<br />
calculated. <strong>The</strong> result as shown <strong>in</strong> table 1.<br />
Table 1. Surface Area Adsorbent<br />
Adsorbent<br />
Spesific Surface Area<br />
(m 2 /g)<br />
<strong>Zeolite</strong> NaY 8,1301<br />
Cr2O3/NaY 2,97% 8,1301<br />
Cr2O3/NaY 3,84% 8,1048<br />
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<br />
Cr 5+ = O<br />
TO 4
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January 24, 2009<br />
Adsorbent which has been obta<strong>in</strong>ed <strong>in</strong> this<br />
research is then used to adsorption <strong>of</strong> NOx gas with<br />
the ability to see how the adsorptivity from each<br />
adsorbent. <strong>The</strong> results <strong>of</strong> adsorption test for each<br />
adsorbent as the follow<strong>in</strong>g:<br />
NO x (mmol)<br />
0.40<br />
0.35<br />
0.30<br />
0.25<br />
0.20<br />
0.15<br />
0.10<br />
0.05<br />
0.00<br />
NaY<br />
Cr O /NaY 2,97% Cr O /NaY 3,8%<br />
2 3 2 3<br />
Figure 5. Relations between the adsorbent with the<br />
amount <strong>of</strong> gas absorbed NOx<br />
On the figure 6, adsorbent shows that most<br />
high adsorptivity is Cr2O3/NaY 3.84% at 0.39<br />
mmol. Adsorptivity adsorbent sequence from the<br />
largest to the smallest is Cr2O3/NaY 3.84% ><br />
Cr2O3/NaY 2.97% > zeolite NaY. Adsorbent with<br />
a specific surface area is large that is expected to<br />
have a high adsorptivity, but the adsorptivity from<br />
the adsorbent is not <strong>in</strong>fluenced by the specific<br />
surface area and acidity, but more <strong>in</strong>fluenced by<br />
the distribution <strong>of</strong> ion Cr 3+ . This can be seen from<br />
the surface area <strong>of</strong> the order <strong>of</strong> the adsorbent :<br />
zeolite NaY = Cr2O3/NaY 2.97% > Cr2O3/NaY<br />
3.84%. From the spesific surface area that zeolite<br />
NaY and Cr2O3/NaY 2.97% have large surface<br />
area but the adsorptivity smaller when compared<br />
with Cr2O3/NaY 3.84%, which has a surface area<br />
<strong>of</strong> the smallest but have the highest adsorptivity if<br />
compared with the other adsorbent. This <strong>in</strong>dicates<br />
that the specific area <strong>of</strong> the adsorbent not affect<br />
adsorptivity.<br />
In terms <strong>of</strong> acidity, the nature acidity <strong>of</strong><br />
Cr2O3/NaY 2,97% and 3,84% is Brønsted acid. On<br />
the other side, zeolite NaY is Lewis acid. From the<br />
data specific surface area and acidity <strong>of</strong> the each<br />
adsorbent, the adsorptivity from the adsorbent is<br />
not <strong>in</strong>fluenced by the specific surface area and the<br />
acidity, but more <strong>in</strong>fluenced by the distribution <strong>of</strong><br />
ion Cr 3+ . <strong>The</strong> adsorbent Cr2O3/NaY 3.84% has ion<br />
Cr 3+ more on the surface if compared with other<br />
adsorbent, so the adsorptivity <strong>of</strong> Cr2O3/NaY 3.84%<br />
will have the highest if compared with the other<br />
adsorbent. This is <strong>in</strong> accordance with the results <strong>of</strong><br />
the test adsorption <strong>of</strong> NOx gas that has been done,<br />
where the NOx gas will be attached to the surface<br />
Cr2O3 <strong>in</strong> the form <strong>of</strong> [-O-N = O +], where N atoms<br />
that has positive charge will be attached to the O<br />
atoms <strong>in</strong> the Cr2O3 so a lot <strong>of</strong> Cr2O3 that are<br />
absorbed and stick on zeolite NaY surface, the NOx<br />
gas that adsorp on the adsorbent will be higher.<br />
Conclusion<br />
Acknowledgements<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
<strong>The</strong> authors are grateful to the Chemistry<br />
Departement, all the participant that help make this<br />
research, and the f<strong>in</strong>ancial support from <strong>The</strong><br />
M<strong>in</strong>istry <strong>of</strong> National Education.<br />
.<br />
References<br />
[1] El - Bahy, Z. H., (2007), “Oxidation <strong>of</strong> Carbon<br />
Monoxide over Cu- and Ag-NaY Catalysts<br />
with Aqueous Hydrogen Peroxide”, Materials<br />
Research Bullet<strong>in</strong>.<br />
[2] Haris, Daniel C., (1997), Explor<strong>in</strong>g Chemical<br />
Analysis, New York : W. H. Freeman and<br />
Company.<br />
[3] Harsono, Heru, (2002), “Pembuatan Silika<br />
Amorf dari Limbah Sekam Padi”, Jurnal Ilmu<br />
Dasar, Vol. 3, No. 2, hal. 98 – 103.<br />
[4] Kil, J. K., Nam, I. S., Park, J. H., Park, S. J.,<br />
(2006), “Quantitative Analysis <strong>of</strong> Nitrogen<br />
Oxides Occluded <strong>in</strong> Heterogeneous Catalysis”,<br />
Patent Application Publication, Pub. No. US<br />
2006/0024836 A1.<br />
[5] Li, G., Jones, C. A., Grassian, V. H., Larsen, S.<br />
C., (2005), “Selective Catalytic Reduction <strong>of</strong><br />
NO2 with Urea <strong>in</strong> Nanocrystall<strong>in</strong>e NaY<br />
<strong>Zeolite</strong>”, Journal <strong>of</strong> Catalysis, 234, hal. 401–<br />
413.<br />
[6] Liu, X., Yan, Z., Wang, H., Luo, Y., (2003), “In<br />
– situ Synthesis <strong>of</strong> NaY <strong>Zeolite</strong> with Coal-<br />
Based Kaol<strong>in</strong>”, Journal <strong>of</strong> Natural Gas<br />
Chemistry, 12, hal. 63-70.<br />
[7] Malek, N. A. N. N., Yus<strong>of</strong>, A. M., (2007),<br />
“Removal <strong>of</strong> Cr(III) From Aqueous Solutions<br />
Us<strong>in</strong>g <strong>Zeolite</strong> NaY Prepared From Rice Husk<br />
Ash”, <strong>The</strong> Malaysian Journal <strong>of</strong> Analytical<br />
Sciences, Vol. 11, No. 1, hal. 76 – 83.<br />
[8] Nakamoto Kazuo. 1978. Infrared and Raman<br />
Spectra <strong>of</strong> Inorganic and Coord<strong>in</strong>ation<br />
Compounds. Third edition. America : John<br />
Wiley & Sons.<br />
[9] Park, Joo-Hyoung., Han, M. S., Park, S. J.,<br />
Kim, D. H., Nam, In-Sik, Yeo, G. K., Kil, J.<br />
K., Youn, Y. K., (2006), “Colorimetric Assay<br />
for a Fast Parallel Screen<strong>in</strong>g <strong>of</strong> NOx Storage”,<br />
Journal <strong>of</strong> Catalysis, 241, hal. 470 – 474.<br />
[10] Prasetyoko, D., Ramli, Z., Endud, S.,<br />
Hamdan, H., Silikowski, B. (2005),<br />
Proceed<strong>in</strong>g Book 538
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January 24, 2009<br />
“Conversion <strong>of</strong> Rice Husk Ash to <strong>Zeolite</strong><br />
Beta”, Waste Management.<br />
[11] Sakamoto, Y., Okumura, K., Kizaki, Y.,<br />
Matsunaga, S., Takahashi, N., Sh<strong>in</strong>joh, H.,<br />
(2006), “Adsorption and Desorption Analysis<br />
<strong>of</strong> NOx and SOx on a Pt/Ba Th<strong>in</strong> Film Model<br />
Catalyst”, Journal <strong>of</strong> Catalysis, 238, hal. 361 –<br />
368.<br />
[12] Sang, S., Liu, Z., Tian, P., Liu, Z., Qu, L.,<br />
Zhang, Y., (2006), “Synthesis <strong>of</strong> Small<br />
Crystals <strong>Zeolite</strong> NaY”, Materials Letters, 60,<br />
hal. 1131 – 1133.<br />
[13] Weitkamp, J and Puppe, L. 1994. Catalysis and <strong>Zeolite</strong>s<br />
Fundamentals an Aplications. Spr<strong>in</strong>ger.<br />
[14] Wojciechowska, M., Ziel<strong>in</strong>ski, M.,<br />
Przystajko, W., Pietrowski, M., (2007), “NO<br />
Decomposition and Reduction by C3H6 Over<br />
Transition Metal Oxides Supported on MgF2”,<br />
Catalysis Today, 119, hal. 44 – 47<br />
[15] Yalç<strong>in</strong>, N., Sev<strong>in</strong>ç, V., (2001), “Studies on<br />
Silica obta<strong>in</strong>ed from Rice Husk”, Ceramics<br />
International, 27, hal. 219 – 224.<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
Proceed<strong>in</strong>g Book 539
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January 24, 2009<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
Synthesis <strong>of</strong> Calcium Phosphate Carbonate-Polyglycolide Composite us<strong>in</strong>g<br />
Precipitation Method<br />
Introduction<br />
Kiagus Dahlan, Arif Rahmadi, Yessie Widya Sari<br />
Department <strong>of</strong> Physics, Faculty <strong>of</strong> Mathematics and Natural Sciences, Institut Pertanian Bogor,<br />
Jalan Meranti, Kampus IPB Dramaga, Bogor, Indonesia<br />
Abstract<br />
Composite <strong>of</strong> calcium phosphate carbonate-polyglycolide has been synthesized us<strong>in</strong>g<br />
precipitation method. Calcium phosphate carbonate was resulted by pour<strong>in</strong>g CaCl2.2H2O <strong>in</strong>to<br />
NaHCO3 and Na2HPO4.2H2O solutions us<strong>in</strong>g precipitation method at temperature <strong>of</strong> 70 o C<br />
and N2 atmosphere to elim<strong>in</strong>ate foreign ions. Porous polyglycolide was resulted from solid<br />
state polymerization <strong>of</strong> sodium chloroacetate at temperature <strong>of</strong> 212 o C. <strong>The</strong> composite was<br />
synthesized by add<strong>in</strong>g polyglycolide <strong>in</strong>to NaHCO3 and Na2HPO4.2H2O us<strong>in</strong>g precipitation<br />
method. <strong>The</strong> precipitate was dried at 110 o C for 10 hours after which the precipitate mass was<br />
then measured. AAS analysis presented Ca/P ratio <strong>of</strong> calcium phosphate carbonate ranged<br />
from 1.46 to 1.67. <strong>The</strong> presence <strong>of</strong> polyglycolide was shown by FTIR spectra. <strong>The</strong> formation<br />
<strong>of</strong> the composite was <strong>in</strong>dicated by sample mass which was close to the calculation mass. FTIR<br />
spectra <strong>of</strong> the composite showed the presence <strong>of</strong> absorption bands <strong>of</strong> calcium phosphate<br />
carbonate and several groups <strong>of</strong> polyglycolide.<br />
Keywords : Composite, precipitation, calcium phosphate, polyglycolide<br />
Bone is a natural composite material<br />
conta<strong>in</strong><strong>in</strong>g about 55% <strong>in</strong>organic m<strong>in</strong>eral, 30%<br />
organic matrix and 15% water [1]. <strong>The</strong> m<strong>in</strong>eral<br />
component <strong>of</strong> bone is a form <strong>of</strong> calcium phosphate<br />
known as hydroxyapatite (HAp). <strong>The</strong> matrix<br />
component is comprised primarily <strong>of</strong> Type I<br />
collagen that is highly aligned, yield<strong>in</strong>g a very<br />
anisotropic structure. This organic component <strong>of</strong><br />
bone is predom<strong>in</strong>antly responsible for its tensile<br />
strength and made an important role <strong>in</strong> skeletal<br />
system to provide the support<strong>in</strong>g structure for the<br />
body. Bone can remodel and adapt itself to the<br />
applied mechanical environment [2,3]. An accident<br />
or bone disease may cause bone damage that<br />
becomes necessary to replace or recontour the<br />
damage <strong>in</strong> the heal<strong>in</strong>g process. Many materials<br />
have been proposed as useful replacements.<br />
<strong>The</strong>re are several techniques deal<strong>in</strong>g with<br />
bone reconstruction such as allograft, autograft, and<br />
xenograft. Autograft is a bone reconstruction us<strong>in</strong>g<br />
one <strong>of</strong> body parts and implanted to other part from<br />
the same <strong>in</strong>dividual. Allograft is implantation from<br />
different <strong>in</strong>dividuals <strong>in</strong> the same species. Xenograft<br />
is implantation from different species. In many<br />
cases, implementation <strong>of</strong> autograft usually does not<br />
cause refusal response from the host body, but the<br />
availability is limited, moreover this can cause<br />
additional operation and prolongation <strong>of</strong> operation<br />
time, <strong>in</strong>creased loss <strong>of</strong> blood, and postoperative<br />
pa<strong>in</strong> [4-6]. On the other hand, allograft and<br />
xenograft sometimes cause refusal response from<br />
host and the availability is also limited. <strong>The</strong>se may<br />
also become media for contagious diseases.<br />
Synthetical biomaterials are expected to be able to<br />
overcome those problems. Good biomaterial for<br />
bone implantation must be biocompatible,<br />
bioactive, no corrotion, non toxic, has long time<br />
stability, strength, and easy to obta<strong>in</strong>.<br />
Hydroxyapatite has been widely used as a<br />
bone replacement material <strong>in</strong> restorative dental and<br />
orthopaedic implant as its chemical and<br />
crystallographic structure be<strong>in</strong>g similar to that <strong>of</strong><br />
bone m<strong>in</strong>eral. Bone substitution needs composite <strong>of</strong><br />
biomaterial with<strong>in</strong> polymer and ceramics<br />
biomaterial. One type <strong>of</strong> polymer match<strong>in</strong>g with<br />
this problem is Polyglycolide (PGA). Polyglycolide<br />
(or polyglycolic acid) is a well-known biomaterial<br />
with excellent biocompatibility and<br />
biodegradability lead to its widespread application<br />
<strong>in</strong> medic<strong>in</strong>e as material for bone implants and bone<br />
fixation device. <strong>The</strong> existence <strong>of</strong> polymer as matrix<br />
is not forever <strong>in</strong> the body, after apatite m<strong>in</strong>eral<br />
coalesces <strong>in</strong> bone and forms healthy bone, the<br />
polymer matrix will disappear. It means that<br />
polymer must be accepted <strong>in</strong> biological<br />
environment and biodegradable [7].<br />
This research aimed to synthesize calcium<br />
phosphate carbonate-polyglicolide composite by<br />
precipitat<strong>in</strong>g calcium, phosphate, and carbonate<br />
compound on polyglycolide.<br />
Proceed<strong>in</strong>g Book 540
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January 24, 2009<br />
Experimental<br />
Polymer matrix preparation<br />
Sodium chloroacetate was placed <strong>in</strong> a<br />
ceramic cup and heated us<strong>in</strong>g furnace with heat<strong>in</strong>g<br />
rate <strong>of</strong> 0.2 o C/m<strong>in</strong>ute until polymerization<br />
temperature, 212 o C, was reached, <strong>in</strong> nitrogen<br />
ambience, result<strong>in</strong>g polyglycolide (PGA) and NaCl.<br />
<strong>The</strong> next step was wash<strong>in</strong>g processes by solv<strong>in</strong>g<br />
polyglycolide powder <strong>in</strong>to hot water and stirred for<br />
about 4 m<strong>in</strong>utes. <strong>The</strong>n the polyglycolide was<br />
filtered and dried at 110 o C for one hour.<br />
Precipitation <strong>of</strong> calcium phosphate carbonate<br />
Solution <strong>of</strong> calcium phosphate carbonate<br />
was prepared from NaHCO3 and Na2HPO4.2H2O<br />
mixed <strong>in</strong>side a beaker glass. CaCl2.2H2O was then<br />
poured <strong>in</strong>to the solution. Variation <strong>of</strong><br />
Table 1 Concentration variation <strong>of</strong> calcium phosphate carbonate<br />
Sample<br />
code<br />
CaCl2.<br />
2H2O<br />
(50ml)<br />
NaHCO3<br />
(50ml)<br />
A 0.2 0.2 0.2<br />
B 0.334 0.2 0.2<br />
Precipitation <strong>of</strong> calcium phosphate carbonate-<br />
polyglycolide composite<br />
<strong>The</strong> calcium phosphate carbonatepolyglycolide<br />
composite was synthesized <strong>in</strong> the<br />
same way as calcium phosphate carbonate. Prior to<br />
the precipitation <strong>of</strong> composite, polyglycolide was<br />
added <strong>in</strong>to NaHCO3 and Na2HPO4.2H2O solutions.<br />
Characterization<br />
AAS analysis was used for identify<strong>in</strong>g<br />
concentrations <strong>of</strong> Ca, Na dan P <strong>in</strong> samples. FTIR<br />
analysis used to determ<strong>in</strong>e conta<strong>in</strong> <strong>of</strong> complex<br />
bench <strong>in</strong> composite.<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
concentrations to make this mixture was shown <strong>in</strong><br />
Table 1.<br />
Precipitation processes were controlled at<br />
a temperature <strong>of</strong> 70 o C and N2 atmosphere. N2<br />
atmosphere was purposed to elim<strong>in</strong>ate foreign ions<br />
from background. To control homogeneity <strong>of</strong><br />
solution, stirr<strong>in</strong>g was performed dur<strong>in</strong>g<br />
precipitation us<strong>in</strong>g magnetic stirrer. Calcium<br />
phosphate carbonate solution as the result <strong>of</strong> the<br />
precipitation was decanted for about 12 hours<br />
before filter<strong>in</strong>g. Afterward, the precipitate was<br />
dried us<strong>in</strong>g furnace at 110 o C for 10 hours. Mass <strong>of</strong><br />
precipitate was then measured us<strong>in</strong>g analytical<br />
balance. This measurement aimed to compare the<br />
mass <strong>of</strong> calcium phosphate carbonate m<strong>in</strong>eral, the<br />
mass <strong>of</strong> PGA matrix and the mass <strong>of</strong> m<strong>in</strong>eralmatrix<br />
composite.<br />
Na2HPO4.2H2O<br />
(50ml)<br />
Results and Discussions<br />
Figure 1 DSC analysis <strong>of</strong> sodium chloroacetate.<br />
Polymer matrix preparation<br />
Porous polyglycolide was obta<strong>in</strong>ed<br />
through polymerization <strong>of</strong> sodium chloroacetate at<br />
212 C result<strong>in</strong>g polyglycolide and sodium<br />
chloride (as by product). Accord<strong>in</strong>g to the analysis<br />
<strong>of</strong> DSC (Figure 1), sodium chloroacetate used <strong>in</strong><br />
this study polymerized at 212 C. This po<strong>in</strong>t was<br />
different from previous study eventhough the type<br />
<strong>of</strong> sodium chloroacetate was identical (MERCK,<br />
98%) [7]. <strong>The</strong>refore, it is suggested for further<br />
study that it is important to analyze the<br />
polymerization po<strong>in</strong>t <strong>of</strong> sodium chloroacetate.<br />
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<strong>The</strong> pore <strong>of</strong> polyglycolide was obta<strong>in</strong>ed through<br />
the elim<strong>in</strong>ation <strong>of</strong> sodium chloride through out the<br />
immersion <strong>of</strong> polyglycolide <strong>in</strong>to aquadest. It was<br />
assumed that the wash<strong>in</strong>g treatment succeeded <strong>in</strong><br />
elim<strong>in</strong>at<strong>in</strong>g the sodium chloride <strong>in</strong> the<br />
polyglycolide as there was a decrease <strong>in</strong> mass <strong>of</strong><br />
polyglycolide as high as 50 % wt (Table 2). This<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
assumption was proven through FTIR spectra.<br />
<strong>The</strong>re was no peak that <strong>in</strong>dicates the presence <strong>of</strong><br />
sodium chloroacetate. Although there was C=O<br />
band, it did not belong to sodium chloroacetate.<br />
XRD spectra <strong>of</strong> this obta<strong>in</strong>ed polyglycolide also<br />
showed that there was only polyglycolide peak.<br />
Table 2 Mass <strong>of</strong> polyglycolide before and after wash<strong>in</strong>g process by warm aquadest<br />
Mass (grams)<br />
Polyglycolide Before After<br />
<strong>The</strong> formation <strong>of</strong> composite<br />
<strong>The</strong> prelim<strong>in</strong>ary <strong>in</strong>dicator <strong>of</strong> the composite<br />
formation was given by the measured mass which<br />
was close to the calculated mass. Table 3 shows<br />
the measured and calculated mass <strong>of</strong> the composite.<br />
Another <strong>in</strong>dicator was given by the presence <strong>of</strong><br />
absorption bands <strong>of</strong> both calcium phosphate<br />
carbonate and several groups <strong>of</strong> polyglycolide <strong>in</strong><br />
the FTIR spectra as presented <strong>in</strong> Table 4.<br />
<strong>The</strong> addition <strong>of</strong> polyglycolide form<strong>in</strong>g the<br />
composite gave an <strong>in</strong>fluence to the FTIR spectra,<br />
particularly at stretch<strong>in</strong>g asymmetric vibration ( 3)<br />
<strong>of</strong> phosphate band (around 1025 cm -1 ) and<br />
stretch<strong>in</strong>g asymmetric vibration ( 3) <strong>of</strong> carbonate<br />
band (around 873 cm -1 ). <strong>The</strong> occurrence <strong>of</strong> (C-O)<br />
Sample<br />
code<br />
Mass m<strong>in</strong>eral<br />
from<br />
precipitation<br />
Mass lost<br />
(%)<br />
1 5.0012 2.4092 51.83<br />
2 4.9049 2.1817 55.52<br />
m<strong>in</strong>eral matrix water<br />
Table 3 Mass <strong>of</strong> samples<br />
Mass<br />
PGA<br />
band <strong>of</strong> polyglycolide tended to disturb the 3 <strong>of</strong><br />
phosphate band so that this band appeared as if<br />
there was a shoulder at around 1210 cm -1 . While the<br />
appearance <strong>of</strong> (COO, CH) band <strong>of</strong> polyglycolide<br />
tended to fades the 3 <strong>of</strong> carbonate band. At higher<br />
concentration, polyglycolide tended to generate the<br />
formation <strong>of</strong> type A carbonate apatite that occurs at<br />
900 cm -1 .<br />
Mass<br />
composite<br />
formed<br />
Mass<br />
calculation<br />
percentage<br />
(%)<br />
A1 55% 30% 15% 0.7263 g 1.8414 g 2.0579 g 89.48<br />
A2 1.3316 g 60% 30% 10% 0.6658 g 1.7406 g 1.9974 g 87.14<br />
A3<br />
70% 20% 10% 0.3806 g 1.5585 g 1.7122 g 91.02<br />
B1 55% 30% 15% 0.8918 g 2.1915 g 2.5268 g 86.73<br />
B2 1.6350 g 60% 30% 10% 0.8175 g 2.1613 g 2.4525 g 88.12<br />
B3<br />
70% 20% 10% 0.4671 g 1.8901 g 2.1021 g 89.91<br />
Calcium phosphate carbonate is <strong>in</strong>dicated<br />
by the appearance <strong>of</strong> (CO3 2- ) and (PO4 3- ). In<br />
samples without polyglycolide, the FTIR spectra <strong>of</strong><br />
those samples are similar. <strong>The</strong>re is no significance<br />
effect <strong>in</strong> Ca/P ratio.<br />
However, when polyglycolide as a matrix<br />
was present, sample A has a dist<strong>in</strong>ct difference<br />
from sample B. Sample A1 has lower transmittance<br />
<strong>of</strong> all bench compared to sample B1 and so did<br />
sample A2 and B2. However, as the percentage <strong>of</strong><br />
matrix <strong>in</strong> the composite decreased, the effect <strong>of</strong><br />
Ca/P is almost undetected as there was no<br />
significant difference <strong>in</strong> percentage <strong>of</strong> transmission<br />
between sample A3 and B3. For all samples, it was<br />
also observed that composite <strong>of</strong> sample A (A1, A2,<br />
and A3) has lower Ca/P ratio compared to<br />
composite <strong>of</strong> sample B (B1, B2, and B3) as<br />
presented by Tables 5 and 6 show<strong>in</strong>g the<br />
concentrations and ratio <strong>of</strong> Ca and P <strong>in</strong> samples.<br />
Proceed<strong>in</strong>g Book 542
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January 24, 2009<br />
Table 4 Calcium phosphate carbonate and polyglycolide absorption band <strong>in</strong> samples<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
Calsium phosphate carbonate wavenumber (cm -1 Code <strong>of</strong><br />
)<br />
samples ACA* CO3 2- (v2) CO3 2- (v3) PO4 3- (v1) PO4 3- (v3) PO4 3- (v4)<br />
A 873.596 1467.65 962.305 1025.94 568.898<br />
A1 900.594 873.596 1043.30 568.898<br />
A2 900.594 873.596 1025.94 565.898,<br />
607.467<br />
A3 873.596 1060.66 561.184<br />
B 873.596 1467.56 958.448 1060.66 603.610<br />
B1 900.594 873.596 1095.37 603.610<br />
B2 900.594 873.596 1060.66 568.098<br />
B3 873.596 1035.59 568.898<br />
Code <strong>of</strong><br />
samples (C-H)<br />
Polyglycolide wavenumber (cm -1 )<br />
(C=O)<br />
<strong>in</strong> ester<br />
(COO, C-H)<br />
A1 2962.13 1751.05 1417.42 815.742<br />
A2 2958.27 1751.05 1417.42 806.742<br />
A3 2962.13 1747.19 1417.42 806.099<br />
B1 2962.13 1747.19 1419.35 815.742<br />
B2 2958.27 1747.19 1417.42 815.742<br />
B3 2958.27 1751.05 1419.35 815.742<br />
Sample code<br />
Ca<br />
Concentration (%)<br />
Na P<br />
A 28.70 3.36 14.32<br />
A1 18.83 2.01 9.96<br />
A2 15.96 2.13 8.02<br />
A3 22.20 2.82 11.48<br />
B 25.88 1.49 12.94<br />
B1 19.85 1.47 9.13<br />
B2 18.89 1.33 9.41<br />
B3 21.06 1.45 10.10<br />
Table 5 Concentrations <strong>of</strong> Ca, Na, andP<br />
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January 24, 2009<br />
Conclusion<br />
Polyglycolide and sodium chloride were<br />
resulted from the polymerization <strong>of</strong> sodium<br />
chloroacetate at 212 C. Porous polyglycolide<br />
obta<strong>in</strong>ed from elim<strong>in</strong>ation <strong>of</strong> sodium chloride<br />
through the immersion <strong>of</strong> polyglycolide <strong>in</strong>to<br />
aquadest could be used as a matrix <strong>of</strong> calcium<br />
phosphate carbonate. Precipitation method enabled<br />
the synthesis <strong>of</strong> composite <strong>of</strong> calcium phosphate<br />
carbonate-polyglycolide. <strong>The</strong> appearance <strong>of</strong><br />
polyglycolide <strong>in</strong>dicated by the disturbance <strong>of</strong> both<br />
3 phosphate and carbonate bands. Phosphate band<br />
tended to have a shoulder occurrence at its 3,<br />
while carbonate band tended to fade away.<br />
References<br />
[1]. Aoki, H. 1991. Science and medical<br />
applications <strong>of</strong> Hydroxyapatite. Institute for<br />
Medical and Dental Eng<strong>in</strong>eer<strong>in</strong>g. Tokyo<br />
Medical and Dental University.<br />
[2] Mickiewicz, RA. 2001. Polymer-calcium<br />
phosphate composites for use as an<br />
Table 6 Ratio <strong>of</strong> Ca/P<br />
Sample code Ca/P<br />
A<br />
A1<br />
A2<br />
A3<br />
B<br />
B1<br />
B2<br />
B3<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
<strong>in</strong>jectable bone substitute.<br />
Department <strong>of</strong> Materials Science and<br />
Eng<strong>in</strong>eer<strong>in</strong>g, Massachusetts Institute <strong>of</strong><br />
Technology.<br />
Proceed<strong>in</strong>g Book 544<br />
1.55<br />
1.46<br />
1.54<br />
1.49<br />
1.55<br />
1.67<br />
1.55<br />
1.61<br />
[3] Emily Y. Ho. 2005. Eng<strong>in</strong>eer<strong>in</strong>g Bioactive<br />
Polymers for the Next Generation <strong>of</strong> Bone<br />
Repair. Drexel University.<br />
[4] Dewi, SU. 2007. Analisis Kuantitatif,<br />
Kekerasan dan Pengaruh Termal Pada<br />
M<strong>in</strong>eral Tulang Manusia. Fakultas<br />
Matematika dan Ilmu Pengetahuan Alam,<br />
Institut Pertanian Bogor.<br />
[5] Langenati, R, Ngatijo, Widjaksana, Latief,<br />
A, Sugeng, B. 2003. Aplikasi<br />
Hidroksiapatit Di Bidang Medis.<br />
Tangerang: Batan, Puspitek Serpong.<br />
[6] Epple, M and Herzberg, O.1997. Porous<br />
Polyglycolide . J Biomed Mater Res (Appl<br />
Biomater) 43: 83–88.<br />
[7] Schwarz, K and Epple, M. 1998.<br />
Biomimetic Crystallization <strong>of</strong> Apatite <strong>in</strong> a<br />
Porous Polymer Matrix. Hamburg: Institute<br />
<strong>of</strong> Inorganic and Applied Chemistry,<br />
University <strong>of</strong> Hamburg.
<strong>The</strong> First International Sem<strong>in</strong>ar on Science and Technology<br />
January 24, 2009<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
An In-Situ Neutron Diffraction <strong>Study</strong> <strong>of</strong> β-Bi2Mo2O9 and γ-Bi2MoO6 as<br />
Partial Oxidation Catalysts<br />
Hamzah Fansui 1 and Dong-ke Zhang 2<br />
1 Chemistry Department, Faculty <strong>of</strong> Mathematics and Natural Sciences<br />
Institut Teknologi Sepuluh Nopember,<br />
Kampus <strong>ITS</strong> Sukolilo, Surabaya, Indonesia, 60111.<br />
2 Centre for Petroleum, Fuels and Energy<br />
<strong>The</strong> University <strong>of</strong> Western Australia,<br />
35 Stirl<strong>in</strong>g Highway, Crawley, Perth, Western Australia 6009<br />
Abstract<br />
<strong>The</strong> dynamics <strong>of</strong> lattice oxygen <strong>in</strong> β-Bi 2Mo 2O 9 and γ-Bi 2MoO 6 as catalysts for partial oxidation <strong>of</strong><br />
propylene to acrole<strong>in</strong> was <strong>in</strong>vestigated us<strong>in</strong>g the neutron diffraction technique. <strong>The</strong> catalyst<br />
characterization experiments were carried out under reaction conditions at 300, 350 and 400 o C us<strong>in</strong>g<br />
the Medium Resolution Powder Diffraction (MRPD). <strong>The</strong> unit cell <strong>of</strong> the β-Bi 2Mo 2O 9 was seen to<br />
expand isotropically to the (111) face with <strong>in</strong>creas<strong>in</strong>g temperature, <strong>in</strong>dicat<strong>in</strong>g that there was no<br />
important atomic coord<strong>in</strong>ate changes <strong>in</strong> the temperature range studied. On the other hand, the unit<br />
cell <strong>of</strong> the γ-Bi 2MoO 6 expanded to the (110) face. <strong>The</strong> difference suggests that the two catalysts have<br />
different activation mechanisms <strong>in</strong> catalys<strong>in</strong>g the partial oxidation reaction. Structure ref<strong>in</strong>ement <strong>of</strong><br />
both catalysts under the <strong>in</strong>-situ conditions shows that certa<strong>in</strong> lattice oxygen ions are more mobile than<br />
others. <strong>The</strong> Oxygen ions No. 3 and 18 <strong>in</strong> β-Bi 2Mo 2O 9 and No. 1 and 5 <strong>in</strong> γ-Bi 2MoO 6 are the mobile<br />
oxygen ions <strong>in</strong> the lattice. <strong>The</strong> mobile lattice oxygen ions are the most probable active oxygen for the<br />
selective oxidation <strong>of</strong> propylene to acrole<strong>in</strong><br />
Keywords: Acrole<strong>in</strong>, Bismuth molybdate, In-Situ Neutron Diffraction, Partial Oxidation,<br />
Propylene.Write five keywords<br />
Introduction<br />
Bismuth molybdates have long been known as active<br />
catalysts for selective oxidation <strong>of</strong> olef<strong>in</strong>s. <strong>The</strong>re are<br />
several phases <strong>of</strong> bismuth molybdates but only three<br />
<strong>of</strong> them are known to be active for partial oxidation <strong>of</strong><br />
propylene to acrole<strong>in</strong>, namely α, β and γ bismuth<br />
molybdates.<br />
Many researchers believe that lattice oxygen<br />
<strong>in</strong> bismuth molybdate catalysts plays an important<br />
role <strong>in</strong> determ<strong>in</strong><strong>in</strong>g the activities <strong>of</strong> bismuth<br />
molybdates <strong>in</strong> catalys<strong>in</strong>g the partial oxidation <strong>of</strong><br />
olef<strong>in</strong>. It has been proven that the oxidation reaction<br />
uses the lattice oxygen and follows the Mars-van<br />
Krevelen mechanisms [1-2]. Several studies have also<br />
shown that the lattice oxygen ions are <strong>in</strong>volved <strong>in</strong> the<br />
oxidation process [1, 3-6]. Furthermore, Haber [7]<br />
mentioned that the ease <strong>of</strong> oxygen movement <strong>in</strong><br />
bismuth molybdates, by the formation <strong>of</strong> shear plane<br />
and rearrangement <strong>of</strong> corner-l<strong>in</strong>ked metal oxides <strong>in</strong>to<br />
edge-l<strong>in</strong>ked octahedrals <strong>of</strong> molybdenum as well as<br />
tungstate oxide, favour their activities and selectivity<br />
towards acrole<strong>in</strong> formation.<br />
Materials and Methods<br />
Experimental<br />
<strong>The</strong> catalysts used <strong>in</strong> the present study were<br />
prepared us<strong>in</strong>g the co-precipitation method from<br />
Bi(NO3)3.5H2O and (NH4)6Mo7O24.4H2O solutions.<br />
Molar ratio <strong>of</strong> Bismuth to Molybdenum was 1 and 2<br />
for the preparation <strong>of</strong> β-Bi2Mo2O9 and γ-Bi2MoO6,<br />
respectively. <strong>The</strong> suspension was kept <strong>in</strong> a water bath<br />
at 70 o C and stirred well to evaporate the liquid<br />
slowly until it became a paste. <strong>The</strong> paste was then<br />
dried at 120 o C for 20 hrs <strong>in</strong> air. <strong>The</strong> dried cake was<br />
crushed and calc<strong>in</strong>ed <strong>in</strong> air at 250 o for 2 hrs followed<br />
by calc<strong>in</strong>ation at 650 o C for 24 hrs for β-Bi2Mo2O9<br />
and at 480 o C for 20 hrs for γ-Bi2MoO6. Room<br />
temperature structure <strong>of</strong> the catalysts thus prepared<br />
was characterized us<strong>in</strong>g both X-ray and Neutron<br />
diffraction techniques. XRD analysis employed Cu<br />
Kα radiation operated at 40 kV and 30 mA. Neutron<br />
diffraction analysis was carried out us<strong>in</strong>g the High<br />
Resolution Powder Diffraction (HRPD). A<br />
monochromatic neutron beam at a wavelength <strong>of</strong><br />
1.495Å was applied. In-situ neutron diffraction<br />
analyses were carried out us<strong>in</strong>g the Medium<br />
Resolution Powder Diffractometer (MRPD) with a<br />
monochromatic neutron beam at a wavelength <strong>of</strong><br />
1.665 Å. <strong>The</strong> catalyst characterisation was carried out<br />
at 300, 350 and 400 o C <strong>in</strong> air and <strong>in</strong> a simulated<br />
reaction atmosphere comprised <strong>of</strong> 1% C3H6, 2% O2<br />
and 97% He <strong>in</strong> a special quartz cell reactor [8]<br />
Proceed<strong>in</strong>g Book 545
<strong>The</strong> First International Sem<strong>in</strong>ar on Science and Technology<br />
January 24, 2009<br />
(Figure 1). All diffractograms were used to ref<strong>in</strong>e the<br />
lattice parameters, <strong>in</strong>ter-atomic distances and thermal<br />
parameters, us<strong>in</strong>g the LHPM Rietica ref<strong>in</strong>ement<br />
method [9].<br />
Figure 1. A schematic <strong>of</strong> the special sample<br />
cell for the <strong>in</strong>-situ MRPD analyses<br />
Results and Discussion<br />
Figure 2 shows HRPD diffractograms and<br />
ref<strong>in</strong>ement fit <strong>of</strong> room temperature -Bi2Mo2O9 and<br />
-Bi2MoO6. Search and Match results us<strong>in</strong>g Jade 6.0<br />
and PDF (Powder Data File) database version 2<br />
reveals that the bismuth molybdate catalysts prepared<br />
<strong>in</strong> this experiment are -Bi2Mo2O9 and -Bi2MoO6.<br />
<strong>The</strong> beta phase corresponds to ICSD<br />
(Inorganic Crystal Structure Database) collection No.<br />
201742 based on structural model reported by Chen<br />
and Sleight [10]. <strong>The</strong> unit cell <strong>in</strong> the model is<br />
monocl<strong>in</strong>ic with unit cell parameters a=11.972(3),<br />
b=10.813(4), c=11.899(2), =90.0 =90.1(0)<br />
=90.0 and unit cell volume V=1540.4. Meanwhile,<br />
the gamma phase corresponds to ICSD collection No.<br />
47139 where the unit cell is orthorhombic and<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
a=5.482(0), b=16.199(1), c=5.509(0), =90.0<br />
=90.0 =90.0 and unit cell volume V=489.2 as<br />
reported by Teller et al. [11]. Structure ref<strong>in</strong>ement<br />
results <strong>of</strong> the beta and gamma phases from their room<br />
temperature HRPD and XRD us<strong>in</strong>g their<br />
correspond<strong>in</strong>g structural model give slightly different<br />
unit cell parameters as shown <strong>in</strong> Table 1.<br />
)<br />
Figure 2. Graphical representation <strong>of</strong> the<br />
ref<strong>in</strong>ement results <strong>of</strong> room temperature<br />
HRPD diffractograms. (A) β-Bi2Mo2O9<br />
and (B) γ-Bi2MoO6.<br />
Table 1. Ref<strong>in</strong>ed unit cell parameters <strong>of</strong> bismuth molybdates <strong>of</strong> room temperature X-ray and Neutron<br />
(HRPD) diffractograms.<br />
Parameters<br />
β-Bi2Mo2O9<br />
γ-Bi2MoO6<br />
X-ray Neutron X-ray Neutron<br />
Volume (Å 3 ) 1534.05(9) 1538.27(5) 489.41(3) 490.84(2)<br />
a (Å) 11.954(0) 11.965(0) 5.484(0) 5.489(0)<br />
b (Å) 10.799(0) 10.810 (0) 16.209(0) 16.225(0)<br />
c (Å) 11.883(0) 11.893 (0) 5.506(0) 5.511(0)<br />
α ( o ) 90.000 90.000 90.000 90.000<br />
β ( o ) 90.143(3) 90.139(2) 90.000 90.000<br />
<strong>The</strong> dynamic changes on the structure <strong>of</strong><br />
beta and gamma phases under reaction condition<br />
<br />
90.000 90.000 90.000 90.000<br />
(<strong>in</strong>creas<strong>in</strong>g temperature and reaction atmosphere)<br />
were studied by HRPD. <strong>The</strong> unit cell <strong>of</strong> the β-<br />
Proceed<strong>in</strong>g Book 546<br />
(b)<br />
(a
<strong>The</strong> First International Sem<strong>in</strong>ar on Science and Technology<br />
January 24, 2009<br />
Bi2Mo2O9 expanded isotropically as the temperature<br />
<strong>in</strong>creased (Figure 2.a). <strong>The</strong> isotropic unit cell<br />
expansion revealed that there is no important atomic<br />
coord<strong>in</strong>ate change <strong>in</strong> the temperature range studied.<br />
<strong>The</strong> thermal parameters did not <strong>in</strong>crease as the<br />
temperature <strong>in</strong>creased. However, some oxygen ions<br />
(No. 3 and 18) <strong>in</strong> the lattice had larger thermal<br />
parameters than the others. <strong>The</strong>se oxygen atoms were<br />
laid <strong>in</strong> the cavities <strong>of</strong> the β-Bi2Mo2O9 crystal and<br />
bonded to molybdenum and bismuth ions. On the<br />
other hand, the unit cell <strong>of</strong> the γ-Bi2MoO6 expanded<br />
more <strong>in</strong> the a and c directions than <strong>in</strong> the b direction<br />
(Figure 2.b). Some oxygen ions <strong>in</strong> the lattice (No. 1<br />
and 5) experienced greater <strong>in</strong>creases <strong>in</strong> their thermal<br />
parameters than the others. Oxygen No 1 was<br />
a, b, c, and beta<br />
0.80%<br />
0.70%<br />
0.60%<br />
0.50%<br />
0.40%<br />
0.30%<br />
0.20%<br />
0.10%<br />
0.00%<br />
a<br />
b<br />
c<br />
beta<br />
Cell Volume<br />
275 300 325 350 375 400 425<br />
Temperature ( o C)<br />
2.50%<br />
2.00%<br />
1.50%<br />
1.00%<br />
0.50%<br />
0.00%<br />
Cell Volume<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
situated between the Mo-O and Bi(2)-O layers while<br />
Oxygen No 5 was on the Mo-O layer and closer to<br />
the Bi(1) layer than the other oxygen ions <strong>in</strong> the Mo-<br />
O layer. <strong>The</strong> specific thermal parameters <strong>of</strong> Oxygen<br />
ions No 1 and 5 <strong>in</strong>dicate that they are probably the<br />
key <strong>in</strong> controll<strong>in</strong>g the catalyst activity for the<br />
selective partial oxidation. In addition, the less lattice<br />
expansion <strong>in</strong> the b direction suggests that oxygen<br />
atoms bridg<strong>in</strong>g the layers were strongly bonded to<br />
molybdenum and/or bismuth, except Oxygen No 1.<br />
<strong>The</strong> lattice oxygen atoms with high thermal<br />
parameters at high temperatures are the source <strong>of</strong> the<br />
oxidis<strong>in</strong>g oxygen responsible for the selective<br />
oxidation <strong>of</strong> propylene to acrole<strong>in</strong>.<br />
a, b and c<br />
1.00%<br />
0.90%<br />
0.80%<br />
0.70%<br />
0.60%<br />
0.50%<br />
0.40%<br />
0.30%<br />
0.20%<br />
0.10%<br />
0.00%<br />
a<br />
b<br />
c<br />
Cell Volume<br />
275 300 325 350 375 400 425<br />
Temperature ( o C)<br />
(a)<br />
(b)<br />
Conclusion<br />
Figure 2. Percentage <strong>of</strong> unit cell extensions <strong>of</strong> a) β-Bi2Mo2O9 and b) γ-Bi2MoO6<br />
4. Y.-H. Han, W. Ueda, Y. Moro-Oka, Applied<br />
Catalysis A: General 176 (1999)<br />
5. L. D. Krenzke, <strong>The</strong> K<strong>in</strong>etics and Mechanism<br />
<strong>The</strong> <strong>in</strong>-situ neutron diffraction study revealed<br />
<strong>of</strong> Propylene Oxidation over Bismuththat<br />
the most probable active lattice oxygen ions<br />
Molybdate,<br />
responsible for the partial oxidation <strong>of</strong> propylene<br />
Bismuth(1)Molybdenum(1)Oxygen(12),<br />
to acrole<strong>in</strong> are oxygen No 3 and 18 <strong>in</strong> -Bi2Mo2O9<br />
and No. 1 and 5 <strong>in</strong> -Bi2MoO6. <strong>The</strong> active oxygen<br />
atoms <strong>in</strong> both bismuth molybdates are slightly<br />
different <strong>in</strong> their nature. In the phase, active<br />
oxygen ions are lay<strong>in</strong>g <strong>in</strong> the crystal’s cavity and<br />
directly bonded to molybdenum and bismuth ions,<br />
while <strong>in</strong> the phase, the active oxygen are<br />
sandwiched between molybdenum and bismuth<br />
oxide layers.<br />
6.<br />
7.<br />
Bismuth(3)Iron(1)Molybdenum(2)Oxygen(12)<br />
and Uranium(1)Antimony(3)Oxygen(10), <strong>in</strong><br />
Chemistry. 1977, <strong>The</strong> University <strong>of</strong><br />
Wiscons<strong>in</strong>: Milwaukee, USA. p. 163-175.<br />
E. Ruckenste<strong>in</strong>, D. B. Dadyburjor, <strong>The</strong><br />
Journal <strong>of</strong> Physical Chemistry 84 (1980) 26<br />
J. Haber, <strong>in</strong> R. K. Grasselli, J. F. Brazdil (Ed.),<br />
Catalysis by Transition Metal Oxides,<br />
American Chemical Society, Wash<strong>in</strong>gton, D.<br />
C., 1985, p. 1-19<br />
References<br />
8. H. Fansuri, Catalytic Partial Oxidation <strong>of</strong><br />
Propylene to Acrole<strong>in</strong>: <strong>The</strong> Catalyst Structure,<br />
1. J. M. Thomas, W. J. Thomas, Pr<strong>in</strong>ciples and<br />
Practice <strong>of</strong> Heterogeneous Catalysis, VCH<br />
Verlagsgesellschaft mbH, We<strong>in</strong>heim, 1997<br />
2. A. Bielanski, J. Haber, Oxygen <strong>in</strong> Catalysis,<br />
Marcel Dekker, Inc., New York, 1991, p. 472-<br />
479.<br />
3. M. M. Bettahar, G. Constent<strong>in</strong>, L. Savary, J.<br />
C. Lavalley, Applied Catalysis A: General 145<br />
(1996)<br />
Catalyst', Journal <strong>of</strong> Solid State Chemistry, vol. 63, pp. 70-75.<br />
Reaction Mechanisms and K<strong>in</strong>etics, Ph.D<br />
<strong>The</strong>sis, Curt<strong>in</strong> University <strong>of</strong> Technology, 2005,<br />
p. 49<br />
9. C. J. Howard, B. A. Hunter, LHPM Manual, A<br />
Computer Program for Rietveld Analysis <strong>of</strong><br />
X-ray and Neutron Powder Diffraction<br />
Patterns, Australian Institute <strong>of</strong> Nuclear<br />
Science and Eng<strong>in</strong>eer<strong>in</strong>g, Sydney, 1997.<br />
10. Chen, H-Y & Sleight, AW, 1986, 'Crystal<br />
Structure <strong>of</strong> Bi2Mo2O9: A Selective Oxidation<br />
Proceed<strong>in</strong>g Book 547<br />
2.50%<br />
2.00%<br />
1.50%<br />
1.00%<br />
0.50%<br />
0.00%<br />
Cell Volume
<strong>The</strong> First International Sem<strong>in</strong>ar on Science and Technology<br />
January 24, 2009<br />
11. Teller, RG, Brazdil, JF & Grasselli, RK, 1984,<br />
'<strong>The</strong> Structure <strong>of</strong> -Bismuth Molybdate,<br />
Bi2MoO6, by Powder Neutron Diffraction',<br />
Acta Crystallographica C, vol. 40, pp. 2001-<br />
2005.<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
Proceed<strong>in</strong>g Book 548
<strong>The</strong> First International Sem<strong>in</strong>ar on Science and Technology<br />
January 24, 2009<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
A Neutron Diffraction <strong>Study</strong> <strong>of</strong> Co and Mn Incorporation <strong>in</strong>to<br />
AlPO4-5 Lattice<br />
Hamzah Fansuri 1 , Mei Dong 2 , Sawsan Jamil Freij 3 , Jianguo Wang 2 and Dong-ke Zhang 4<br />
1 Chemistry Department, Faculty <strong>of</strong> Mathematics and Natural Sciences<br />
Institut Teknologi Sepuluh Nopember,<br />
Kampus <strong>ITS</strong> Sukolilo, Surabaya, Indonesia, 60111.<br />
2 State Key Laboratory <strong>of</strong> Coal Conversion, Institute <strong>of</strong> Coal Chemistry, Ch<strong>in</strong>ese Academy <strong>of</strong> Sciences, P.O.<br />
Box 165, Taiyuan, Shanxi 030001, Ch<strong>in</strong>a<br />
3 Centre for Fuels and Energy-Curt<strong>in</strong> University <strong>of</strong> Technology, GPO Box U1987, WA 6845, Australia<br />
4 Centre for Petroleum, Fuels and Energy, <strong>The</strong> University <strong>of</strong> Western Australia,<br />
35 Stirl<strong>in</strong>g Highway, Crawley, Perth, Western Australia 6009<br />
h.fansuri@chem.its.ac.id<br />
Abstract<br />
Incorporation <strong>of</strong> Co 2+ and Mn 2+ <strong>in</strong>to the lattice <strong>of</strong> AlPO 4-5 to alter its acidity and redox properties <strong>in</strong><br />
order to improve the AlPO catalytic activity was studied us<strong>in</strong>g the neutron diffraction and analysed<br />
us<strong>in</strong>g the Rietveld ref<strong>in</strong>ement method. Several Co 2+ and Mn 2+ substituted AlPO 4-5 samples were<br />
synthesised us<strong>in</strong>g a hydrothermal method and then calc<strong>in</strong>ed at 550 o C <strong>in</strong> air before the neutron<br />
diffraction analyses. Electron microscopy images <strong>of</strong> the AlPOs showed that they were ma<strong>in</strong>ly<br />
agglomerates <strong>of</strong> hexagonal plates and prisms where no clear difference was observed between Co and<br />
Mn substituted AlPO 4-5. Rietveld ref<strong>in</strong>ement <strong>of</strong> the neutron diffraction data <strong>in</strong> the Pcc2 group<br />
showed that the substitution <strong>of</strong> alum<strong>in</strong>ium with either cobalt or manganese did not affect the structure<br />
<strong>of</strong> AlPO 4-5 significantly and no other phases <strong>of</strong> Mn or Co were detected. This is an <strong>in</strong>dication that<br />
the Co and Mn ions were homogenously distributed <strong>in</strong> the AlPO 4-5 framework and will have similar<br />
catalytic selectivity to that <strong>of</strong> unsubstituted AlPO 4-5. Further ref<strong>in</strong>ements are required to fully<br />
understand the Co 2+ and Mn 2+ <strong>in</strong>corporation <strong>in</strong>to the AlPO 4-5 lattice.<br />
Keywords: Neutron diffraction, Alum<strong>in</strong>ophosphate molecular sieves, Transition metal<br />
<strong>in</strong>corporation.<br />
Introduction<br />
Alum<strong>in</strong>ophosphate molecular sieves (AlPOs) are<br />
important materials for their potential applications <strong>in</strong><br />
catalysis, adsorption and separation. <strong>The</strong> AlPO4-5<br />
generally consists <strong>of</strong> a tetrahedral structure <strong>of</strong> AlO4<br />
and PO4, which corner-share an oxygen atom to build<br />
a three-dimensional framework with molecule-sized<br />
channels [1]. However, the framework lacks acidic<br />
and redox active sites and thus does not possess<br />
catalytic activity. Incorporation <strong>of</strong> transition metal<br />
ions can alter the AlPO catalytic activity. For<br />
example, CoAPO-5 is an excellent catalyst for<br />
selective oxidation <strong>of</strong> alkanes due to its highly<br />
dispersed redox centres and proper pore structure [2].<br />
Although many publications have reported the<br />
synthesis <strong>of</strong> MeAPOs, little is known about the<br />
detailed nature <strong>of</strong> the metal <strong>in</strong>corporation <strong>in</strong> the<br />
framework. Progress <strong>in</strong> the designed synthesis <strong>of</strong><br />
these microporous catalysts with desired locations <strong>of</strong><br />
active sites and well def<strong>in</strong>ed atomic environment is<br />
limited due to the lack <strong>of</strong> adequate knowledge <strong>of</strong> the<br />
transient active ions from the precursor gel to the<br />
templated solid microporous materials.<br />
This paper reports our effort <strong>in</strong> the<br />
determ<strong>in</strong>ation <strong>of</strong> metal <strong>in</strong>corporation <strong>in</strong> AlPO4-5<br />
us<strong>in</strong>g a neutron diffraction technique. Neutron<br />
diffraction is a sensitive probe for this <strong>in</strong>corporation<br />
s<strong>in</strong>ce Al and P have different scatter<strong>in</strong>g lengths. <strong>The</strong><br />
<strong>in</strong>itial structure model <strong>of</strong> the Co- and Mn-AlPO4 was<br />
deduced from the unsubstituted AlPOs with a<br />
hexagonal symmetry and strict alternation <strong>of</strong> Al and P<br />
<strong>in</strong> the framework (space group P6cc) [3, 4].<br />
Materials and Methods<br />
Experimental<br />
<strong>The</strong> Co- and Mn-AlPO4 were synthesised accord<strong>in</strong>g<br />
to the verified method [5]. Samples were crystallised<br />
at 200 o C for 2, 8, 16 and 24 hours. <strong>The</strong>y were then<br />
calc<strong>in</strong>ed <strong>in</strong> a muffle furnace <strong>in</strong> air (flow rate: 100<br />
ml/m<strong>in</strong>) with a heat<strong>in</strong>g rate <strong>of</strong> 10 ºC per m<strong>in</strong>ute to 550<br />
o C and kept at this temperature for 6 hours.<br />
<strong>The</strong> XRD analyses <strong>of</strong> all samples were performed<br />
us<strong>in</strong>g Cu Kα radiation operat<strong>in</strong>g at 40 kV and 30 mA.<br />
Neutron Diffraction was used to characterise the Co 2+<br />
and Mn 2+ substituted molecular sieves at room<br />
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temperature <strong>in</strong> air us<strong>in</strong>g the Medium Resolution<br />
Powder Diffractometer (MRPD) over 3 o – 138 o <strong>of</strong><br />
two-theta. A Ge crystal monochromator was used to<br />
provide a monochromatic neutron beam at 1.665 Ǻ.<br />
Unit cell parameters were ref<strong>in</strong>ed us<strong>in</strong>g RIETICA, a<br />
rietveld ref<strong>in</strong>ement s<strong>of</strong>tware 6 . <strong>The</strong> SEM images were<br />
also taken us<strong>in</strong>g a Philips XL30 Scann<strong>in</strong>g Electron<br />
Microscope fitted with a SE, BSE and EDS detectors.<br />
Results and Discussion<br />
Figures 1 and 2 show diffractograms <strong>of</strong> Neutron-<br />
Medium Resolution Powder Diffraction (MRPD) and<br />
XRD, respectively, collected at room temperature for<br />
10 samples <strong>of</strong> cobalt and manganese<br />
alum<strong>in</strong>ophosphate. <strong>The</strong> patterns have shown that the<br />
crystall<strong>in</strong>ity <strong>of</strong> <strong>of</strong> Mn-AlPO <strong>in</strong>creases with the<br />
crystallization time while the crystall<strong>in</strong>ity <strong>of</strong> Co-AlPO<br />
reaches a maximum at 8 hour <strong>of</strong> crystallization and<br />
decreases with longer crystallization time. <strong>The</strong><br />
crystal<strong>in</strong>ity is taken as the ratio between the peak<br />
heights versus FWHM (Full Width <strong>of</strong> Half<br />
Maximum).<br />
Figure 1 Diffractograms <strong>of</strong> Neutron-Medium<br />
Resolution Powder Diffraction (MRPD)<br />
Blue l<strong>in</strong>e = CoAlPO4-5 and Red l<strong>in</strong>e =<br />
MnAlPO4-5.<br />
<strong>The</strong> data from diffractograms (MRPD and XRD)<br />
were ref<strong>in</strong>ed <strong>in</strong> Pcc2 group us<strong>in</strong>g Rietica S<strong>of</strong>tware to<br />
<strong>in</strong>vestigate the effect <strong>of</strong> metal substitution on the<br />
crystal structure and parameters. An example <strong>of</strong><br />
ref<strong>in</strong>ement results is shown <strong>in</strong> Figures 3 and 4 for the<br />
MRPD data for Co and Mn alum<strong>in</strong>ophosphate,<br />
respectively.<br />
3000<br />
2500<br />
2000<br />
1500<br />
1000<br />
500<br />
3500<br />
3000<br />
2500<br />
2000<br />
1500<br />
1000<br />
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0<br />
5 15 25 35 45 55 65 75 85 95 105 115 125<br />
500<br />
Figure 5 <strong>The</strong> ref<strong>in</strong>ed data for Co-AlPO4-5<br />
crystallised for 16 hours<br />
0<br />
5 25 45 65 85 105 125<br />
Figure 6 <strong>The</strong> ref<strong>in</strong>ed data for Mn-AlPO4-5<br />
crystallised for 16 hours<br />
Analysis <strong>of</strong> the X-ray diffractogram <strong>of</strong> Co- and<br />
Mn-AlPO4 reveals that their structure are better<br />
described as hav<strong>in</strong>g a Pcc2 rather than P6cc<br />
symmetry. Prelim<strong>in</strong>ary ref<strong>in</strong>ements, either with X-ray<br />
or neutron diffraction patterns, have shown that<br />
substitution <strong>of</strong> alum<strong>in</strong>ium with either cobalt or<br />
manganese did not affect the bulk structure <strong>of</strong> AlPO4-<br />
5 significantly and no other phases <strong>of</strong> Mn or Co were<br />
detected. It <strong>in</strong>dicates that Co and Mn are<br />
homogenously distributed <strong>in</strong> the AlPO4-5 framework.<br />
Table 1 compares the crystal lattice parameters for the<br />
unsubstituted and metal-substituted<br />
alum<strong>in</strong>ophosphate samples studied. Further<br />
ref<strong>in</strong>ements are required to fully understand the<br />
structure by vary<strong>in</strong>g the atomic positions with degree<br />
<strong>of</strong> substitution<br />
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Table 1. Unit cell parameters for pure AlPO4-5 and the metal-substituted AlPO4-5<br />
Phase<br />
Unit cell (Pcc2)<br />
a ∆ b ∆ c ∆<br />
AlPO(Unsubsituted<br />
) 13.794 23.901 8.417<br />
CoAlPO (2 hrs) 13.770 8 23.859 13 8.389 2<br />
CoAlPO (8 hrs) 13.775 6 23.868 10 8.392 1<br />
CoAlPO (16 hrs) 13.771 6 23.876 10 8.391 1<br />
CoAlPO (24 hrs) 13.771 5 23.879 9 8.393 1<br />
MnAlPO (2 hrs) 13.772 6 23.888 11 8.396 1<br />
MnAlPO (8 hrs) 13.778 6 23.882 11 8.396 1<br />
MnAlPO (16 hrs) 13.778 6 23.871 11 8.395 1<br />
MnAlPO (24 hrs) 13.773 6 23.880 11 8.394 2<br />
.<br />
<strong>The</strong> possibility that the Co- and Mn-AlPO4- different crystallographic faces. This may <strong>in</strong>duce<br />
5 hav<strong>in</strong>g preferred orientation is justified by their preferred orientation effect <strong>in</strong> the diffraction patterns<br />
electron microscope images as shown <strong>in</strong> Figures 5 as some faces would be expressed more than others,<br />
and 6.<br />
depend<strong>in</strong>g on the overall composition <strong>of</strong> the samples<br />
Electron microscopic images show that the<br />
AlPO4 ma<strong>in</strong>ly consists <strong>of</strong> agglomerates <strong>of</strong> hexagonal<br />
plates and some prisms. It is also shown that both<br />
Co-AlPO4-5 and Mn-AlPO4-5 have two ma<strong>in</strong><br />
morphologies; each morphology is dom<strong>in</strong>ated by<br />
analysed.<br />
Figure 3 SEM Images <strong>of</strong> CoAlPO4-5, crystallised for 24 hours<br />
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Conclusion<br />
Figure 4 SEM Images <strong>of</strong> MnAlPO4-5, crystallised for 24 hours<br />
<strong>The</strong> present study has shown that crystals <strong>of</strong> Co<br />
and Mn substituted alum<strong>in</strong>ophosphates consist<br />
ma<strong>in</strong>ly <strong>of</strong> agglomerates <strong>of</strong> hexagonal plates and<br />
prisms. No clear difference was observed between<br />
Co and Mn substituted AlPO4-5. Prelim<strong>in</strong>ary<br />
ref<strong>in</strong>ements <strong>of</strong> the neutron diffraction data <strong>in</strong> the<br />
Pcc2 group have shown that the substitution <strong>of</strong><br />
alum<strong>in</strong>ium with either cobalt or manganese did not<br />
affect the structure <strong>of</strong> AlPO4-5 significantly and no<br />
other phases <strong>of</strong> Mn or Co were detected. This is<br />
an <strong>in</strong>dication that Co and Mn are homogenously<br />
distributed <strong>in</strong> the AlPO4-5 framework and may<br />
suggest similar selectivity to that <strong>of</strong> the<br />
unsubsituted AlPO4-5.<br />
References<br />
1. Ribeiro, F.R., F. Alvarez, C. Henriques, F.<br />
Lemos, J.M. Lopes, and M.F. Ribeiro, J. Mol.<br />
Catal. A, 96 (1995) 245.<br />
2. G. Sanker, R. Raja, J. M. Thomas, Catal. Lett.,<br />
55 (1998) 15.<br />
3. Bennet JM, Cohen JP, Flanigen EM, Pluth JJ,<br />
Smith JV, Am Chem Soc Symp Ser 218<br />
(1983)109.<br />
4. Qiu S, Pang W, Kessler H, Guth JL, <strong>Zeolite</strong>s 8<br />
(1989) 440.<br />
5. Harry Robson (Editor), “Syntheses <strong>of</strong> Zeolitic<br />
Materials”, Elsevier B.V., Amsterdam, 2001.<br />
p.90.<br />
6. C. J. Howard, B. A. Hunter, LHPM Manual, A<br />
Computer Program for Rietveld Analysis <strong>of</strong><br />
X-ray and Neutron Powder Diffraction<br />
Patterns, Australian Institute <strong>of</strong> Nuclear<br />
Science and Eng<strong>in</strong>eer<strong>in</strong>g, Sydney, 1997<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
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Relation Between <strong>Addition</strong> <strong>of</strong> Alum<strong>in</strong>o-Silicate with Alkali-Silica Reaction and<br />
Geopolimer Product<br />
Anggaria Maharani, Lukman Atmaja 1 and Hamzah Fansuri<br />
Laboratories <strong>of</strong> Physical Chemistry, Department <strong>of</strong> Chemistry, Faculty <strong>of</strong> Mathematic and Natural Sciences, Sepuluh<br />
Nopember Institut <strong>of</strong> Technology (<strong>ITS</strong>), Surabaya, Indonesia.<br />
1) Correspond<strong>in</strong>g author, Phone: +62-31-5943353<br />
email: lukman_at@chem.its.ac.id,<br />
Introduction<br />
Abstract<br />
Geopolymers have been studied for several decades due to their excellent mechanical and thermal properties,<br />
as well as chemical and fire resistance. Geopolymer were synthesized via reaction <strong>of</strong> alum<strong>in</strong>osilicate<br />
material, fly ash, with alkal<strong>in</strong>esilicate solution at ambient temperature. In this paper, geopolymers was<br />
modified by the addition the amount <strong>of</strong> <strong>in</strong>soluble additive, α-Al 2O 3 (Corundum) and SiO 2 (Quartz) to Si/Al<br />
variation. <strong>The</strong> result show that the geopolymer product (Si/Al=5.0) has highest strength (65 MPa) as compare<br />
to other sample. <strong>The</strong> current work used XRD, the quartz and mullite were found both <strong>of</strong> fly ash and<br />
geopolymer product. This study also <strong>in</strong>dicates that not only amorphous phases but also crystall<strong>in</strong>e phases<br />
<strong>in</strong>volve <strong>in</strong> the geopolymerization process.<br />
Keywords : crystall<strong>in</strong>e phase reactivity <strong>in</strong> geopolymerization, fly ash utilization, geopolymers, alkali-silica<br />
reaction<br />
Power stations, us<strong>in</strong>g coal like-fuels, are<br />
worldwide energy source, <strong>in</strong>clud<strong>in</strong>g Indonesia will<br />
dramatically <strong>in</strong>crease its coal fired-power station to<br />
produce 10000 MW electricity. <strong>The</strong> generation <strong>of</strong><br />
electricity by coal combustion produces fly ash (80-<br />
90%) and bottom ash (10-20%) [1,2]. It is considered<br />
that volume <strong>of</strong> fly ash production will reach 800<br />
MTon <strong>in</strong> around the world) <strong>in</strong> 2010 where only a<br />
small part (20-30%) <strong>of</strong> these ashes are used at present<br />
[3]. Thus, the <strong>in</strong>crease <strong>of</strong> coal fired power station will<br />
give serious problems to particularly our environment<br />
like air pollution, contam<strong>in</strong>ant <strong>of</strong> water and decrease<br />
<strong>of</strong> ecosystem quality.<br />
<strong>The</strong> important advances <strong>in</strong> the search for<br />
new application for fly ashes are be<strong>in</strong>g achieved.<br />
Among the ma<strong>in</strong> achievements is a new <strong>in</strong>organic<br />
material which is called geopolymer. Geopolymer is a<br />
synthetic material analogues <strong>of</strong> natural zeolite.<br />
Geopolymer materials has excellent mechanical<br />
properties, <strong>in</strong>clud<strong>in</strong>g fire and acid resistance [4].<br />
<strong>The</strong>se properties make geopolymer an alternative<br />
construction material compared to Portland cement.<br />
Geopolymer has better strength than Portland cement<br />
[5].<br />
Fly ashes conta<strong>in</strong> sufficient amount <strong>of</strong><br />
alum<strong>in</strong>a and silica that can be used as source<br />
materials for geopolymerisation reaction. It was<br />
reported that the type and nature <strong>of</strong> the start<strong>in</strong>g<br />
materials will directly affect the f<strong>in</strong>al physical and<br />
chemical properties <strong>of</strong> a geopolymer [6]. Moreover,<br />
the ma<strong>in</strong> m<strong>in</strong>eral component <strong>in</strong> fly ash like quartz and<br />
mullite might also affect the geopolymer product due<br />
to their activation reaction [7]. Geopolymer from Fly<br />
ash with more amorphous phases are more reactive<br />
than those conta<strong>in</strong>s more crystall<strong>in</strong>e phases [8]. Xu<br />
and van Deveneter also reported that Si and Al <strong>in</strong><br />
amorphous phase are more dissolvable <strong>in</strong> an alkal<strong>in</strong>e<br />
solution than the crystall<strong>in</strong>e phase [9].<br />
<strong>The</strong> aim <strong>of</strong> the present study is to prove the<br />
role <strong>of</strong> Si and Al <strong>in</strong> crystall<strong>in</strong>e phases and their<br />
contribution to Si/Al ratio <strong>in</strong> the geopolymerisation<br />
process and product. <strong>The</strong> present study explores the<br />
effect <strong>of</strong> the <strong>in</strong>soluble silicone and alum<strong>in</strong>ium content<br />
<strong>in</strong> a series <strong>of</strong> composition on the mechanical strength,<br />
microstructural and to identify and quantify such<br />
products.<br />
Experimental<br />
Materials<br />
Fly ash class F (accord<strong>in</strong>g to ASTM C 618-<br />
03) used <strong>in</strong> the synthesis <strong>of</strong> all geopolymer matrices<br />
was obta<strong>in</strong>ed from Asam-asam power station <strong>in</strong> South<br />
Kalimantan, Indonesia. Its chemical composition is<br />
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shown <strong>in</strong> Table 1. <strong>The</strong> composition <strong>of</strong> fly ash was<br />
determ<strong>in</strong>ed by X-ray fluorescence (XRF) method.<br />
Quartz/SiO2 (Merck, 99%), Corrundum/α-Al2O3<br />
(Merck, 95%), sodium silicate, distilled water and<br />
analytical-grade NaOH were used throughout all<br />
experiment.<br />
Geopolymerisation<br />
<strong>The</strong> ash and either quartz or corundum <strong>in</strong> the<br />
required proportions were mixed with the activat<strong>in</strong>g<br />
solution to prepare cyl<strong>in</strong>drical specimens (15x30<br />
mm). Alkal<strong>in</strong>e solution (NaOH, sodium silicate and<br />
H2O) and source materials were mixed for 3 m<strong>in</strong>utes.<br />
<strong>The</strong> mixture was cast <strong>in</strong> plastic moulds and vibrated<br />
for 10 second. Specimens was cured at 60°C for 24h.<br />
At the end <strong>of</strong> the cur<strong>in</strong>g process, the specimens were<br />
removed from the oven and kept <strong>in</strong> the mould for 7,<br />
14, 21 and 28 days.<br />
Compressive strength test<strong>in</strong>g<br />
Result and Discussion<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
Compressive strength test<strong>in</strong>g was carried out<br />
on the molded, cyl<strong>in</strong>drical speciments with 1:2<br />
diameter to length ratio. Three cyl<strong>in</strong>ders <strong>of</strong> each<br />
sample were tested and the experimental values be<strong>in</strong>g<br />
averaged. All samples were tested at 7, 14, 21 and 28<br />
days. An Torsee Universal Test<strong>in</strong>g Mach<strong>in</strong>e Au-5<br />
20490 was used for all tests.<br />
Morphology, FT-<strong>in</strong>frared analysis and X-ray<br />
diffraction<br />
<strong>The</strong> samples were studied by SEM/EDX<br />
us<strong>in</strong>g a JEOL JSM-6360LA scann<strong>in</strong>g microscope<br />
equipped with an energy dispersive X-ray at the<br />
accelerat<strong>in</strong>g voltage <strong>of</strong> 10 kV. FT-<strong>in</strong>frared spectra<br />
were recorded on a spectrometer us<strong>in</strong>g the KBr pellet<br />
technique. X-ray powder diffraction data were<br />
obta<strong>in</strong>ed us<strong>in</strong>g a Phillips PW 1800 diffractometer<br />
with Cu Kα radiation (40 kV, 30 mA) with scann<strong>in</strong>g<br />
rate 2°/m<strong>in</strong> from 5° to 70°.<br />
Table 1 Elemental composition Fly ash, expressed as oxides (%)<br />
Mechanical strength<br />
Fig. 1 shows the variation <strong>in</strong> compressive<br />
strength with cur<strong>in</strong>g time for the various work<strong>in</strong>g<br />
system (3 cube per test were tested). At short cur<strong>in</strong>g<br />
time (7 day), an <strong>in</strong>crease <strong>in</strong> the soluble silica content<br />
at Si/Al = 5.0 favored the development <strong>of</strong> high<br />
mechanical strength <strong>in</strong> material (compressive strength<br />
> 50 MPa). At slightly longer cur<strong>in</strong>g times (14 day),<br />
however, a substantial <strong>in</strong>crease was observed <strong>in</strong> the<br />
strength <strong>of</strong> systems. Longer cur<strong>in</strong>g times had a<br />
consistently beneficial effect on the mechanical<br />
strength <strong>of</strong> the all matrices.<br />
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Compressive strength (MPa)<br />
70<br />
65<br />
60<br />
55<br />
50<br />
45<br />
40<br />
35<br />
30<br />
25<br />
7 d<br />
14 d<br />
21 d<br />
28 d<br />
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20<br />
1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5<br />
<strong>The</strong> mol ratio <strong>of</strong> Si/Al<br />
Fig. 1. Mechanical strength vs mol ratio <strong>of</strong> Si/Al for various cur<strong>in</strong>g time<br />
<strong>The</strong> geopolymerisation <strong>of</strong> fly ash, fly ash-corundum,<br />
and fly ash-quartz was conducted with the mol ratio<br />
<strong>of</strong> Si/Al was varied from 1.5 to 6.0 <strong>in</strong> NaOH and<br />
Na2SiO3 solutions. It was found that all geopolymer<br />
products have satisfactory compressive strength<br />
(Fig.1). When a mixture <strong>of</strong> fly ash and corundum was<br />
geopolymerised, theere was no significant change <strong>in</strong><br />
the compressive strength, namely around 34 MPa. On<br />
the other hand, addition <strong>of</strong> SiO2 (Quartz) results <strong>in</strong><br />
dramatic <strong>in</strong>crease <strong>in</strong> the compressive strength. It was<br />
faound that the strength reached up to 65 MPa,<br />
doubled than those prepared by corrundum addition.<br />
<strong>The</strong> Figure also shows that the <strong>in</strong>crease <strong>in</strong> Si/Al ratio<br />
improve the compressive strength <strong>of</strong> geopolymers.<br />
However, when the ratio is higher that 5 it start to<br />
decl<strong>in</strong>es.<br />
<strong>The</strong> variation <strong>in</strong> mechanical strength as a<br />
result <strong>of</strong> variation <strong>in</strong> Si/Al ratio has a relation with<br />
material reactivity. <strong>The</strong> propety can be analysed by<br />
elemental analysis us<strong>in</strong>g ICP for silicone and<br />
alum<strong>in</strong>ium dissolved from the material <strong>in</strong> a strong<br />
alkal<strong>in</strong>e solution. <strong>The</strong> analysis results showed that the<br />
solubility <strong>of</strong> alum<strong>in</strong>ium <strong>in</strong> corundum was only<br />
0.067% while <strong>in</strong> fly ash it was 4.57%. <strong>The</strong> same trend<br />
was also shown by quartz where the solubility <strong>of</strong><br />
silicone was only 2.06%. Thus, it can be seen that a<br />
high reactivity raw materials were needed to produce<br />
a high performance geopolymer.<br />
3.2 Sample crystall<strong>in</strong>ity and FT-Infrared<br />
Characteristics<br />
X-ray powder diffraction pattern for the<br />
material studied, <strong>in</strong>clud<strong>in</strong>g orig<strong>in</strong>al fly ash, SiO2 and<br />
corundum, are shown <strong>in</strong> Fig. 2. In contrast to the<br />
other two, the fly ash shows a substantial amorphous<br />
phase (hump registered between 2θ = 20° and 2θ =<br />
30°) <strong>in</strong> its structure with the peaks <strong>of</strong> the quartz<br />
(SiO2, JCPDS 03-0444) and mullite (3Al2O3.2SiO2,<br />
JCPDS 15-0776) as a rema<strong>in</strong>der. It has been reported<br />
[9] that source materials like fly ash are usually have<br />
a higher reactivity <strong>in</strong> geopolymerization process.<br />
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Fig. 3 shows the XRD pattern <strong>of</strong> the<br />
geopolymer synthesized at Si/Al molar ratio =3.0;<br />
3.5 and 5.0. <strong>The</strong> Figure shows crystall<strong>in</strong>e phases<br />
detected <strong>in</strong> the product <strong>of</strong> geopolymer, namely quartz<br />
.<br />
Si/Al=5.0 + TiO 2<br />
Si/Al=3.5 + TiO 2<br />
Si/Al=1.5 + TiO 2<br />
Q<br />
Q<br />
R<br />
R<br />
5 10 15 20 25 30 35 40 45 50 55 60 65 70<br />
5 10 15 20 25 30 35 40 45 50 55 60 65 70<br />
2θ<br />
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Fly ash<br />
Quartz<br />
Corundum<br />
Fig. 2. <strong>The</strong> XRD pattern <strong>of</strong> fly ash, quartz and corundum<br />
R M<br />
R<br />
R Q<br />
M<br />
Q<br />
M<br />
R<br />
MM<br />
Q/M<br />
R<br />
Q M R<br />
M<br />
M<br />
Fig. 3. <strong>The</strong> XRD pattern <strong>of</strong> some geopolymer<br />
products. Q= quartz, M= mullite, and R= Rutile<br />
2θ<br />
M<br />
R<br />
and mullite. <strong>The</strong> addition <strong>of</strong> <strong>in</strong>soluble material<br />
(Quartz and Corundum) <strong>in</strong>creased the <strong>in</strong>tensity <strong>of</strong><br />
quartz (<strong>in</strong> 2θ = 27, <strong>in</strong>crease from 438 to 487) and<br />
mullite (<strong>in</strong> 2θ = 42, <strong>in</strong>crease from 89 to 291).<br />
<strong>The</strong> FTIR spectra <strong>of</strong> the orig<strong>in</strong>al fly ash and<br />
geopolymer products are shown <strong>in</strong> Fig. 4. <strong>The</strong> fly ash<br />
spectrum shows one broad absorbance registered at<br />
1089cm -1 which is ascribed to T-O asymmetric<br />
stretch<strong>in</strong>g vibration (T=Si or Al). Absorbance at<br />
466cm -1 ascribed to υ4 (O-Si-O) bend<strong>in</strong>g modes <strong>of</strong><br />
SiO4 tetrahedra and around 782 cm -1 is assigned as<br />
symmetrical stretch<strong>in</strong>g <strong>of</strong> Si-O-Si [6,10]. An<br />
absorbance at 679 cm -1 is assigned for quartz as a<br />
part <strong>of</strong> the fly ash component[11]. <strong>The</strong>re was no<br />
significant differences between the FTIR pattern <strong>of</strong><br />
fly ash and the geopolymer products which means<br />
that the most vibrant forms <strong>of</strong> the molecular cha<strong>in</strong>s<br />
exist<strong>in</strong>g <strong>in</strong> the raw materials are reta<strong>in</strong>ed <strong>in</strong> the<br />
geopolymer product<br />
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1464<br />
1427 784 690<br />
1081 1018 560<br />
1089<br />
Wave number (cm -1 )<br />
On the other hand, the geopolymer products either<br />
with or without <strong>in</strong>soluble material additives were<br />
found to have vitreous phases compris<strong>in</strong>g <strong>of</strong> SiO2 and<br />
Al2O3 namely quartz and mullite. <strong>The</strong> presence <strong>of</strong><br />
quartz <strong>in</strong> the FTIR spectra is shown by a series <strong>of</strong><br />
bands located at around 1081, 784 (double band), 690<br />
and 460 cm -1 . Meanwhile, the presence <strong>of</strong> mullite is<br />
shown by bands at around at 560 cm -1 (band<br />
associated with the octahedral alum<strong>in</strong>ium present <strong>in</strong><br />
mullite) [12]. Absorption band which is appeared at<br />
around 1427 cm -1 has been assigned to the presence<br />
<strong>of</strong> the sodium bicarbonate [10] as a result <strong>of</strong> the<br />
reaction between excess sodium with atmospheric<br />
carbondioxide. <strong>The</strong> geopolymer absorption band at<br />
around 1089 cm -1 (asymmetric stretch<strong>in</strong>g vibration <strong>of</strong><br />
459<br />
782 679 466<br />
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Si/Al = 6.0<br />
Si/Al = 5.0<br />
Si/Al = 3.5<br />
Si/Al = 3.0<br />
Si/Al = 1.5<br />
Fly ash<br />
Fig. 4. FTIR spectra <strong>of</strong> fly ash and geopolymers product<br />
T-O) is shifted to between 1081 and 1018 cm -1 . <strong>The</strong><br />
shift <strong>in</strong>dicates that the vitreous components <strong>in</strong> fly ash<br />
are reacted with the alkali activator and the alkal<strong>in</strong>e<br />
alum<strong>in</strong>osilicate gels are be<strong>in</strong>g formed [11].<br />
Microscopic morphology<br />
<strong>The</strong> micrographs presented <strong>in</strong> this paper<br />
depict the typical microstructure by the material at<br />
Si/Al ratio (Fig. 5 and 6). Fig. 5 is a SEM image<br />
show<strong>in</strong>g the characteristic morphology <strong>of</strong> the orig<strong>in</strong>al<br />
fly ash, quartz and corundum. <strong>The</strong> ash (a) consists <strong>of</strong><br />
a series <strong>of</strong> spherical vitreous particles <strong>of</strong> different<br />
sizes (diameter rang<strong>in</strong>g from 0.2 to 5 µm). While<br />
quartz powder (b) shows a prismatic shape with<br />
particle size mostly larger than 50 µm and corundum<br />
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powder displays hexagonal shapes with particle size mostly smaller than 5 µm.<br />
(a) (b)<br />
(c)<br />
Fig. 5. SEM Picture (a) orig<strong>in</strong>al fly ash, (b) Quartz, (c) Corundum<br />
Fig. 6a shows the geopolymer product<br />
without <strong>in</strong>soluble material additives. <strong>The</strong> picture<br />
correspond to a geopolymer cured for 28 days. Fly<br />
ash particles which have reacted with the alkali<br />
solution are observed to co-exist with some unreacted<br />
sphere (see ). Fig. 6b shows the geopolymer<br />
product with corundum addition. Corundum crystals<br />
(see ) are detected under the matrix layer on the<br />
broken surface. Fig. 6c shows the product with quartz<br />
additive. Almost all quartz particles reacted with the<br />
alkali solution.<br />
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<strong>The</strong> ma<strong>in</strong> reaction product from<br />
geopolymerization <strong>in</strong> alkal<strong>in</strong>e condition is sodiumalum<strong>in</strong>o-silicate<br />
gel that are gett<strong>in</strong>g compacted dur<strong>in</strong>g<br />
precipitation step with more gel proceed<strong>in</strong>g from<br />
other particles giv<strong>in</strong>g place to a geopolymer matrix.<br />
<strong>The</strong> EDX analyses for the geopolymer matrix show<br />
that the Si/Al ratio <strong>in</strong> the ma<strong>in</strong> reaction products is<br />
3.5 <strong>in</strong> the geopolymer with no additive), 3.0 with 0.03<br />
mol corundum additive and 5.0 with 0.3 mol quartz<br />
additive. This phenomenon suggests that some added<br />
corrundum and quartz may still exist <strong>in</strong> the<br />
geopolymer product.<br />
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Conclusion<br />
(a) (b)<br />
Product <strong>of</strong> geopolymers from fly ash and<br />
<strong>in</strong>soluble material (Quartz and corundum) has been<br />
successfully synthesized. It is found that there is an<br />
<strong>in</strong>terrelationship among the <strong>in</strong>soluble additives that<br />
affect the f<strong>in</strong>al structure and properties <strong>of</strong> geopolymer<br />
products. It was shown that the reactivity <strong>of</strong> start<strong>in</strong>g<br />
material affect the mechanical properties where<br />
highly reactive start<strong>in</strong>g material produces high<br />
mechanical strength. <strong>The</strong> lower reactivity <strong>of</strong> the<br />
quartz, the <strong>in</strong>teraction between the source material<br />
and the alkal<strong>in</strong>e solution and the re<strong>in</strong>forc<strong>in</strong>g effect<br />
caused by the unreacted quartz particles give<br />
satisfactory mechanical strength <strong>of</strong> the formed<br />
geopolymers. <strong>The</strong> Si/Al ratio (5.0) gives the highest<br />
mechanical strength. This study also <strong>in</strong>dicates that not<br />
(c)<br />
Fig. 6. SEM images <strong>of</strong> Geopolymer product<br />
(a) Si/Al=3.5, (b) Si/Al=3.0 and (c) Si/Al=5<br />
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only amorphous phases but also crystall<strong>in</strong>e phases<br />
<strong>in</strong>volve <strong>in</strong> the geopolymerization process.<br />
Acknowledgements<br />
<strong>The</strong> authors gratefully acknowledge fund<strong>in</strong>g<br />
from the Directorate General <strong>of</strong> Higher Education,<br />
Indonesia, under Hibah Pasca grant.<br />
References<br />
[1] Bankowski, P., Zou, L., Hodges, R.,”Us<strong>in</strong>g<br />
<strong>in</strong>organic polymer to reduce leach rates <strong>of</strong><br />
metals from brown coal fly ash”, M<strong>in</strong>eral<br />
Eng<strong>in</strong>eer<strong>in</strong>g, 17 (2004) 159-166.<br />
[2] Perera, D. S., Uchida, O., Vance, E.R.,<br />
F<strong>in</strong>nie, K.S., (2007), “Influence <strong>of</strong> Cur<strong>in</strong>g<br />
Schedule on the Integrity og Geopolymers”,<br />
Proceed<strong>in</strong>g Book 559
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January 24, 2009<br />
Journal <strong>of</strong> Material Science, 42 (2007)<br />
3099-3106.<br />
[3] Bakharev, T., “<strong>The</strong>rmal Behaviour <strong>of</strong><br />
Geopolymers Prepared us<strong>in</strong>g Class F Fly<br />
Ash and Elevated Temperature Cur<strong>in</strong>g”,<br />
Cement and Concrete Research, 36 (2006)<br />
1134-1147.<br />
[4] Fletcher, A.R., MacKenzie, K. J. D.,<br />
Nicholson, L. C., Shimida, Shiro, “<strong>The</strong><br />
composition range <strong>of</strong> alum<strong>in</strong>oslicate<br />
geopolymers”, Journal <strong>of</strong> European<br />
Ceramic Society, 25 (2005) 1471-1477.<br />
[5] Fernandez-Jimenez, A., Palomo, A., and<br />
Criado, M., “Microstructure Development<br />
<strong>of</strong> Alkali-Activated Fly Ash Cement : A<br />
Descriptive Model”, Cement and Concrete<br />
Research, 35 (2005) 1204-1209.<br />
[6] Van Jaarsveld, J.G.S., van Deventer, J.S.J.<br />
and G.C. Lukey., “<strong>The</strong> Effect <strong>of</strong><br />
Composition and Temperature on <strong>The</strong><br />
Properties <strong>of</strong> Fly Ash- and Kaol<strong>in</strong>ite-Based<br />
Geopolymers”, Chemical Eng<strong>in</strong>eer<strong>in</strong>g<br />
Journal, 8 (2002) 63-73.<br />
[7] Xu, Hua, Lukey, G. C., van Deventer, J. S.<br />
J., (2006), “<strong>The</strong> effect <strong>of</strong> Ca on Activation <strong>of</strong><br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
Class C-, Class F-Fly ash and Blast Furnace<br />
Slag, Cement and Concrete Research, xx<br />
(2006) xxx-xxx.<br />
[8] Xu, Hua, Van Deventer, J.S.J., “<strong>The</strong><br />
geopolymerisation <strong>of</strong> alum<strong>in</strong>osilicate<br />
m<strong>in</strong>erals”, International Journal <strong>of</strong> M<strong>in</strong>eral<br />
Process<strong>in</strong>g, 59 (2000) 247-266.<br />
[9] Xu, Hua dan J.S.J., Van Deventer,<br />
“Geopolymerisation <strong>of</strong> Multiple M<strong>in</strong>erals”,<br />
Journal <strong>of</strong> M<strong>in</strong>eral Engeneer<strong>in</strong>g, 15 (2002)<br />
1131-1139.<br />
[10] Lee, W. K. W., J.S.J., Van Deventer, “<strong>The</strong><br />
effect <strong>of</strong> the <strong>in</strong>organic salt contam<strong>in</strong>ation on<br />
the strength and durability <strong>of</strong> geopolymers”,<br />
Colloidal and Surface A : Physicochem.<br />
Eng. Aspects., 211 (2002) 115-126.<br />
[11] Fernandez-Jimenez, A., Palomo, A.,<br />
“Composition and Microstructure <strong>of</strong> Álcali<br />
Activated Fly Ash B<strong>in</strong>der : Effect the<br />
Activator”, Cement and Concrete Research,<br />
35 (2005) 1984-1992.<br />
[12] Criado, M., Fernández-Jiménez, A., Palomo,<br />
A., (2007), “Alkali activation <strong>of</strong> fly ash :<br />
Effect <strong>of</strong> the SiO2/Na2O ratio Part I : FTIR<br />
study”, Microporous and Mesoporous<br />
Materials, 106 (2007) 180-191.<br />
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Dye Sensitized Solar Cell Build<strong>in</strong>g by Anchored-Tio2<br />
Wahyun<strong>in</strong>gsih, 1,2 Joshua Watts 3 , Indriana Kart<strong>in</strong>i, 2 Narsito 2 , Lianzhou Wang 3 , Max Lu 3<br />
1 Department <strong>of</strong> Chemistry, Faculty Mathematic and Natural Science Sebelas Maret University<br />
Ir. Sutami Street, 36A, Kent<strong>in</strong>gan, Surakarta, Indonesia.<br />
E-mail: w.sayekti.yahoo.com, phone: 62-274-368381<br />
2 Department <strong>of</strong> Chemistry, Faculty Mathematic and Natural Science Gadjah Mada University<br />
Sekip Utara, Yogyakarta 55281, Indonesia<br />
3 ARC Centre <strong>of</strong> Excellence for Functional Nanomaterials, Level 5 AIBN Build<strong>in</strong>g 74 Brisbane Qld 4072<br />
Australia<br />
Abstract<br />
In this study, mesoporous TiO 2 with 30 nm pore size diameter synthesized us<strong>in</strong>g the template method<br />
with a short-range ordered-framework structure was successfully used as an electrode material <strong>in</strong><br />
dye-sensitized solar cells. <strong>The</strong> higher light-to-electricity energy conversion efficiency is attributed to<br />
the novel physicochemical properties <strong>of</strong> mesoporous TiO 2, which <strong>in</strong>clude high surface area, anchored<br />
by silyl agent, and uniform nanochannels. <strong>The</strong> high surface area adsorbs large quantities <strong>of</strong> the<br />
sensitized dye, result<strong>in</strong>g <strong>in</strong> the generation <strong>of</strong> a higher photocurrent density. A significant <strong>in</strong>fluence <strong>of</strong><br />
the mesopore structure on photovoltaic performance was also observed based on these novel<br />
properties. <strong>The</strong> photovoltaic performance <strong>of</strong> the dye-sensitized solar cells composed <strong>of</strong> mesoporous<br />
TiO 2 is expected to be further improved through the use <strong>of</strong> an anchor group, which has higher thermal<br />
stability. <strong>The</strong>refore, mesoporous TiO 2, used as an electrode material <strong>in</strong> DSSCs, may provide a means<br />
<strong>of</strong> obta<strong>in</strong><strong>in</strong>g higher efficiencies <strong>in</strong> dye sensitized solar cells, possibly approach<strong>in</strong>g their theoretical<br />
efficiency value <strong>in</strong> future.<br />
Keywords: belum ada<br />
Introduction<br />
S<strong>in</strong>ce the power<strong>in</strong>g work <strong>of</strong> Regan and Gratzel (1), a<br />
great attention has been paid to dye sensitized solar<br />
cell (DSSC) as cheap, effective and environmentally<br />
benign candidates for a new generation <strong>of</strong> solar<br />
power. Solar cells based on dye-sensitization <strong>of</strong> TiO2<br />
electrodes are regarded as a regenerative low-cost<br />
alternative to conventional solid-state devices. DSSC<br />
is a photoelectrochemical device which effectively<br />
utilizes a property <strong>of</strong> nanocrystal<strong>in</strong>e wide bandgap<br />
metal oxide semiconductor porous electrode.<br />
Nanocrystall<strong>in</strong>e TiO2, particularly <strong>in</strong> the anatase<br />
phase, has been extensively <strong>in</strong>vestigated as a potential<br />
material for dye-sensitized solar cells (DSSCs) (1).<br />
Currently, this k<strong>in</strong>d <strong>of</strong> solar cell reaches an efficiency<br />
exceed<strong>in</strong>g 10% <strong>of</strong>fer<strong>in</strong>g a realistic option for<br />
convert<strong>in</strong>g light to electrical energy. However, it is<br />
not easy to ga<strong>in</strong> 10% efficiency, which is still far<br />
from the theoretical efficiency <strong>of</strong> 33%.<br />
Generally, a DSSC consists <strong>of</strong> <strong>in</strong>dium t<strong>in</strong> oxide,<br />
(ITO), dye modified TiO2 electrode, electrolyte, and a<br />
counter electrode. To establish high energy<br />
conversion efficiency, mesoporous TiO2 electrode <strong>of</strong><br />
a large surface area have been <strong>in</strong>vestigated<br />
extensively as a key material for DSSC (1). <strong>The</strong><br />
efficiency <strong>of</strong> 10% was obta<strong>in</strong>ed by us<strong>in</strong>g mesoporous<br />
TiO2 as electrode materials (12). Over the whole<br />
range <strong>of</strong> 0–40 mm, the amount <strong>of</strong> dye adsorbed by the<br />
mesoporous TiO2 films was about 1.5–2 times greater<br />
than that by the P-25 films (12). This high efficiency<br />
is attributable to the physicochemical properties <strong>of</strong><br />
mesoporous TiO2, such as surface area, ordered<br />
structure, particles size and uniform pore size (12). In<br />
this study, mesoporous TiO2 was synthesized with<br />
triblock copolymer Pluronic P123 as the structure<br />
direction template to satisfy this need. In order to<br />
make breakthroughs <strong>in</strong> progress, a great deal <strong>of</strong><br />
attention has also been focused on develop<strong>in</strong>g new<br />
sensitizers (2,3), new electrolytes (4,8,16,17), new<br />
model counter electrodes (5,10,15) and new<br />
semiconductor electrode materials (2,6,9). Recently,<br />
an efficiency <strong>of</strong> 10.2% was obta<strong>in</strong>ed us<strong>in</strong>g a N719<br />
dye as a sensitizer (7), and a new record efficiency <strong>of</strong><br />
11.04% was achieved us<strong>in</strong>g a modified electrolyte<br />
(11). One <strong>of</strong> the strategies to improve conversion<br />
efficiency is to <strong>in</strong>crease high harvest<strong>in</strong>g efficiency by<br />
<strong>in</strong>creas<strong>in</strong>g the amount <strong>of</strong> dye <strong>in</strong> the TiO2 electrode<br />
us<strong>in</strong>g anchor<strong>in</strong>g group onto TiO2 surface.<br />
In this article, we present the photophysic and<br />
photoelectrochemical characteristics <strong>of</strong> mesoporous<br />
TiO2, anchored by silyl agent, abbreviated as<br />
anchored-TiO2. Photosensitizer was anchored onto<br />
TiO2 surface via anchor group to ga<strong>in</strong> chemical<br />
bond<strong>in</strong>g between TiO2 and dye. Compared to<br />
nanowires or nanorods, mesoporous anchored-TiO2<br />
has a high surface area (approx. 140.1 m 2 g -1 after<br />
calc<strong>in</strong>ated at 400 o C), and also uniform nanochannels<br />
that can be easily accessed by the electrolyte for I3 -<br />
ion transport. Sensitized anchor<strong>in</strong>g-TiO2 was applied<br />
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for the electrode <strong>of</strong> DSSC. <strong>The</strong> <strong>in</strong>cident photon to<br />
current conversion efficiency (IPCE) <strong>of</strong> the cell made<br />
from anchored TiO2 was <strong>in</strong>vestigated. <strong>The</strong>re are many<br />
factors limit<strong>in</strong>g the cell performance, among which<br />
light harvest<strong>in</strong>g efficiency is the most important.<br />
Materials and Methods<br />
Materials<br />
Nanocrystal<strong>in</strong>e TiO2 was synthesized via self<br />
assembly-sol–gel technique adopted followed<br />
previous work (19). Titanium tetra isopropoxide<br />
(TTIP) was purchased from Aldrich, triblock<br />
copolymer HO(CH2CH2O)20(CH2CH(CH3)O)70<br />
(CH2CH2O)20H (Mav = 5750, designated<br />
EO20PO70EO20; Pluronic P123) was received as a gift<br />
from BASF, acetylacetonate (acac) was purchased<br />
from Merck, 2-propanol (iPr) and hydrochloric acid<br />
(HCl) 37% was purchased from Merck. TiO2 film<br />
prepared on <strong>in</strong>dium t<strong>in</strong> oxide (resistivity: 10 Ω/cm 2 )<br />
conductive glass (Asahi Glass, Japan) and Pt coated<br />
FTO conduct<strong>in</strong>g glass (Dyesol). Complexes<br />
compound were prepared us<strong>in</strong>g CoCl2 from Merck,<br />
am<strong>in</strong>opropyltrimethoxysilane (APTS) from Aldrich,<br />
and 4-(2-piridilazoresorc<strong>in</strong>ol) (PAR) from Aldrich.<br />
Methanol used as solution <strong>of</strong> <strong>in</strong> situ complexes<br />
sensitizer formation was purchased from Merck.<br />
Sealant spacer, alum<strong>in</strong>um back cover, electrolyte (EL-<br />
HSE) and N719 dye were purchased from Dyesol.<br />
Instrumental<br />
Crystal structure <strong>of</strong> TiO2 powders were<br />
analyzed by X-ray diffraction (XRD) measurements<br />
us<strong>in</strong>g Cu Kα radiation (Shimadzu XRD-6000).<br />
Differential thermal analysis (DTA) and thermal<br />
gravimetric analysis (TGA) and fourier transform<br />
<strong>in</strong>fra red spectrophotometer (FTIR) were used to<br />
observe template replac<strong>in</strong>g process. Pore size<br />
distribution and surface area were calculated us<strong>in</strong>g N2<br />
adsorption-desorption data from Autosorp NOVA<br />
1000. Scann<strong>in</strong>g Electron Microscope (SEM)<br />
<strong>in</strong>clud<strong>in</strong>g Energy Dispersive X Ray Analysis (EDX)<br />
specimen (Joel JSM 6360LA) was employed to<br />
<strong>in</strong>vestigate the morphology <strong>of</strong> the anchored TiO2 film.<br />
<strong>The</strong> absorption and reflectant spectrum was analyzed<br />
by UV-Vis spectrophotometer (SHIMADZU UV<br />
1799 Pharma-Spec) equipped with specularreflectance<br />
accessories. Anneal<strong>in</strong>g process <strong>of</strong> TiO2<br />
film preparation was carried out us<strong>in</strong>g a Furnace<br />
Carbolite CWF 1300 with a heat<strong>in</strong>g rate <strong>of</strong> 5 o C/m<strong>in</strong><br />
at 400 o C for 2 hour.<br />
Preparation <strong>of</strong> Anchored-TiO2 Photoelectrodes<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
TiO2 film was fabricated on the <strong>in</strong>dium t<strong>in</strong><br />
oxide (ITO) covered glass substrate (Asahi Glass<br />
Japan, 10 Ω/cm 2 ) by doctor bland technique. Anatase<br />
TiO2 particles (7-8 nm <strong>in</strong> size) were prepared by<br />
us<strong>in</strong>g a published method (19). TiO2 pastes were<br />
prepared by add<strong>in</strong>g water, acetylacetonate, and triton-<br />
X 100 (10:1:2 v/v). <strong>The</strong> film thickness was prepared<br />
by SEM. <strong>The</strong> apparent film size was 5 mm x 5 mm.<br />
<strong>The</strong> films were annealed at 400 o C for 2 hour with a<br />
ris<strong>in</strong>g rate <strong>of</strong> 5 o C/m<strong>in</strong>. TiO2 film was immersed <strong>in</strong> the<br />
anchor<strong>in</strong>g ligand am<strong>in</strong>opropyltrimethoxysilane (5%)<br />
for 5 times, and then r<strong>in</strong>sed with methanol creat<strong>in</strong>g<br />
anchored-TiO2. Anchored-TiO2 film was immersed <strong>in</strong><br />
the Co 2+ solution (10 -4 M), then <strong>in</strong> the 4-(2piridylazo)<br />
resorc<strong>in</strong>ol (10 -4 M) for 2 hour. After dye<br />
adsorption via <strong>in</strong> situ complexes formation, the colour<br />
<strong>of</strong> the th<strong>in</strong> films changed to a deep red.<br />
Solar cell assembly<br />
<strong>Step</strong>wise <strong>of</strong> DSSC build<strong>in</strong>g <strong>in</strong>clud<strong>in</strong>g (1)<br />
preparation <strong>of</strong> dye sensitised photoanode cell, (2) the<br />
use <strong>of</strong> Pt-coated on conductive glass electrode, and<br />
(3) assembly <strong>of</strong> sandwiched dye sensitized solar cell.<br />
<strong>The</strong> dye-sensitized TiO2 electrode was<br />
<strong>in</strong>corporated <strong>in</strong>to a th<strong>in</strong>-layer, sandwiched solar cell<br />
(Fig.8). <strong>The</strong> area <strong>of</strong> the TiO2 electrodes was 0.5 x 0.5<br />
cm 2 . <strong>The</strong> Pt sputtered on a transparent conduct<strong>in</strong>g<br />
glass (SnO2-F) (Dyesol) was used as the counter<br />
electrode. A thermoplastic sealant film spacer (50 µm<br />
nom<strong>in</strong>al thickness, TPS 109129-50 from Dyesol) was<br />
used to prevent the cell from short-circuit<strong>in</strong>g when<br />
the counter- and work<strong>in</strong>g electrodes were clamped<br />
together. <strong>The</strong> electrolyte (EL-HSE electrolyte from<br />
Dyesol) was placed <strong>in</strong>side counter and work<strong>in</strong>g<br />
electrodes through a small hole <strong>in</strong> counter electrode.<br />
Electrolyte addition was kept <strong>in</strong> vacuum desiccators.<br />
After electrolyte addition (without air bubble<br />
formation), the cell was pressed together with<br />
electrolyte sealer (thermoplastic backed alum<strong>in</strong>ium<br />
strip) <strong>in</strong> the back side. DSSC cell was tested with a<br />
solar simulator, which has an <strong>in</strong>put power <strong>of</strong> 250 watt<br />
and able to reach a voltage range <strong>of</strong> about 0.2-0.5 V.<br />
This <strong>in</strong>dicates that the cell is ready for IPCE<br />
measurement.<br />
Fig 1. Build<strong>in</strong>g component <strong>of</strong> dye sensitized solar cell<br />
IPCE measurement<br />
Action spectra <strong>of</strong> the monochromatic<br />
<strong>in</strong>cident photon to current conversion efficiency<br />
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(IPCE) for the solar cells were measured with a Oriel<br />
QE/IPCE measurenment kit Model QE-PV-SI from<br />
Newport Corporation. We employed an AM1.5 solar<br />
simulator with 300 watt Xenon Lamp as the light<br />
source. <strong>The</strong> <strong>in</strong>cident light <strong>in</strong>tensity was calibrated<br />
with a standard solar cell for silicon solar cell<br />
produced by Japan Quality Assurance Organization<br />
Results and Discussion<br />
A monochromatic <strong>in</strong>cident photon to current<br />
conversion efficiency (%IPCE) <strong>of</strong> 0.9 was obta<strong>in</strong>ed<br />
at 655 nm composed <strong>of</strong> mesoporous TiO2. <strong>The</strong><br />
photocurrent yield measured at 655 nm was found to<br />
depend on the counter ion <strong>of</strong> the iod<strong>in</strong>e/triiod<strong>in</strong>e<br />
redox electrolyte.<br />
IPCE%<br />
1<br />
0.9<br />
0.8<br />
0.7<br />
0.6<br />
0.5<br />
0.4<br />
0.3<br />
0.2<br />
0.1<br />
0<br />
350 450 550 650 750 850 950 1050<br />
Wevelength (nm)<br />
IPCE(%)<br />
10<br />
9<br />
8<br />
7<br />
6<br />
5<br />
4<br />
3<br />
2<br />
1<br />
0<br />
IPCE(%)<br />
.<br />
IPCE (%)<br />
0.2<br />
0.18<br />
0.16<br />
0.14<br />
0.12<br />
0.1<br />
0.08<br />
0.06<br />
0.04<br />
0.02<br />
0<br />
.<br />
1<br />
0.8<br />
0.6<br />
0.4<br />
0.2<br />
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0<br />
350 450 550 650 750 850 950 1050<br />
750 850 950 1050<br />
Wavelength (nm)<br />
Wavelength (nm)<br />
350 450 550 650 750 850 950 1050<br />
Wavelength (nm)<br />
Fig. 2. Incident photon to electron conversion efficiency (IPCE) <strong>of</strong> (a) mesoporous TiO2/am<strong>in</strong>osilyl-Co II -<br />
piridylazoresorc<strong>in</strong>ol and (b) P25 TiO2/am<strong>in</strong>osilyl-Co II -piridylazo resorc<strong>in</strong>ol (c) mesoporous TiO2/N719.<br />
Insert: row photocurrent action spectra along visible region.<br />
Based on the figures, there are correlations<br />
between IPCE spectra (Fig. 10) and UV VIS<br />
absorption spectra <strong>of</strong> related cell (Fig. 11).<br />
Excitation dyes electrons seen <strong>in</strong> UV VIS<br />
absorption will be <strong>in</strong>jected to the conduction band<br />
<strong>of</strong> electrode TiO2. <strong>The</strong> cell performance improves<br />
significantly if the dye acts not only as an absorber<br />
but also as an efficiency block<strong>in</strong>g layer (Schmith-<br />
Mende et al, 2005). <strong>The</strong> recomb<strong>in</strong>ation <strong>of</strong><br />
photogeneration electrons and hole <strong>in</strong> the band <strong>of</strong><br />
all solar cells are the ma<strong>in</strong> reasons for their less<br />
efficiency. DSSCs, <strong>in</strong> which the electrons and hole<br />
exist <strong>in</strong> separate chemical phases, are subject<br />
almost exclusively to <strong>in</strong>terfacial recomb<strong>in</strong>ation. We<br />
suggest the lower result <strong>of</strong> am<strong>in</strong>osilyl anchored-<br />
TiO2 based DSSC compared to mesoporous<br />
TiO2/N719 is due to <strong>in</strong>efficient block<strong>in</strong>g layer as a<br />
consequence <strong>of</strong> the recomb<strong>in</strong>ation <strong>of</strong><br />
photogeneration electrons and holes. <strong>The</strong> sluggish<br />
efficient <strong>in</strong>terfacial charge transfer between the<br />
TiO2 and dye complexes anchored to the TiO2<br />
surface also propose the lower result <strong>of</strong> anchored-<br />
TiO2 based DSSC. Unfortunately, for the second<br />
periods transition metals Co II used <strong>in</strong> this study, the<br />
ratio <strong>of</strong> <strong>in</strong>jection over recapture ratio k<strong>in</strong>j/kb lower<br />
that 10 3 .<br />
<strong>The</strong> nanocrystal<strong>in</strong>e films with particles size<br />
commensurate or smaller that their Bohr radius<br />
exhibits quantum size properties, which can be<br />
illustrated <strong>in</strong> photocurrent action spectra <strong>of</strong><br />
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mesoporous TiO2/am<strong>in</strong>osilyl-Co II -<br />
piridylazoresorc<strong>in</strong>ol (Fig. 2a) and <strong>of</strong> mesoporous<br />
TiO2/N719 (Fig 2c).. This means that there is a<br />
potential barrier between the particles and that the<br />
particles constitut<strong>in</strong>g the film can, <strong>in</strong> some respect,<br />
be regarded as <strong>in</strong>dividual entities. Quantum size<br />
effect occur if crystal size <strong>of</strong> TiO2 less than 10 nm.<br />
Fig.3 shows dependency <strong>of</strong> crystal size on<br />
anneal<strong>in</strong>g temperature. Anneal<strong>in</strong>g until 400 O C still<br />
get quantum size TiO2. In the absent <strong>of</strong> quantum<br />
size effect, the ext<strong>in</strong>ction spectrum is described by<br />
the Mie’s <strong>The</strong>ory (26). By Mie’s <strong>The</strong>ory, a very<br />
small colloidal semiconductor particle removes<br />
light from the <strong>in</strong>cident beam both by scatter<strong>in</strong>g and<br />
absorption.<br />
Crystal Size (nm)<br />
25<br />
20<br />
15<br />
10<br />
5<br />
0<br />
0 200 400 600 800 1000<br />
Temperature (C)<br />
Fig. 3. Dependency <strong>of</strong> TiO2 crystal size on<br />
anneal<strong>in</strong>g temperature. Anneal<strong>in</strong>g<br />
temperature rate 5 o C/m<strong>in</strong>. ( ____anatase, ---<br />
rutile)<br />
<strong>The</strong> BET surface area <strong>of</strong> mesoporous TiO2<br />
(140.1 m 2 g -1 ) is higher than that <strong>of</strong> P-25 (approx.<br />
55 m 2 g -1 ), result<strong>in</strong>g <strong>in</strong> more dye be<strong>in</strong>g adsorbed<br />
per unit thickness <strong>of</strong> film. <strong>The</strong> high-adsorption<br />
property <strong>of</strong> mesoporous TiO2 allows high<br />
photocurrent action spectra properties <strong>of</strong> DSSC<br />
based mesoporous TiO2 (Fig. 2a and Fig. 2b). <strong>The</strong><br />
higher efficiency is attributable to the<br />
physicochemical properties <strong>of</strong> mesoporous TiO2,<br />
such as high surface area, ordered structure, particle<br />
size and uniform pore size. <strong>The</strong> results <strong>of</strong> the<br />
characterization <strong>of</strong> the mesoporous TiO2 are<br />
depicted <strong>in</strong> Fig. 4 (data calculations were shown <strong>in</strong><br />
Table 1). <strong>The</strong> pore size distribution was very<br />
narrow and the highest pore diameter was estimated<br />
to be 30 nm. <strong>The</strong> isotherm is <strong>of</strong> type IV,<br />
characteristic <strong>of</strong> mesoporous materials. <strong>The</strong><br />
hysteresis loop exhibited by the specimen is ma<strong>in</strong>ly<br />
between the H1- and H2-types.<strong>The</strong> character <strong>of</strong><br />
small size distribution expla<strong>in</strong>s the low efficiency<br />
<strong>in</strong> the P25 film, because <strong>of</strong> the diffusion <strong>of</strong> I 3- ion <strong>in</strong><br />
electrolyte become a slow and limits the current<br />
production.<br />
Experiment results can be illustrated <strong>in</strong> the form <strong>of</strong><br />
figures (graphics or picture, see example Figure 1).<br />
Title <strong>of</strong> figure (10 pts) is set under the figure.<br />
Figure can be formatted s<strong>in</strong>gle or double column. It<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
should set centered alignment, and the resolution <strong>of</strong><br />
scanned picture has to be not less then 300 dpi.<br />
(a)<br />
(b)<br />
Fig 4. Characteristic <strong>of</strong> (a) isotherm adsorptiondesorption<br />
N2 and (b) pore size distribution<br />
<strong>of</strong> mesoporous TiO2 (synthesized at molar<br />
ratio <strong>of</strong> TTIP/P123/acac/H2O/iPr =<br />
1/0,051/0,53/12/30)<br />
Table 1. <strong>The</strong> BET data and pore characteristic <strong>of</strong><br />
TiO2 used <strong>in</strong> DSSCs cells<br />
Surface<br />
area<br />
(m 2 Pore<br />
volume<br />
/g) cm 3 Average<br />
pore size<br />
/g (nm)<br />
mesoporous 140.1 216.6 6.2<br />
TiO2<br />
TiO2 P25 58 0.291 1.04<br />
Many researchers have tried to reproduce the<br />
overall efficiency <strong>of</strong> 10% for N719 DSSC, reported<br />
<strong>in</strong> 1993 (13). However, this record rema<strong>in</strong>ed<br />
unmatched for several years until 2001, when a<br />
black dye-adsorbed DSSC gave an efficiency <strong>of</strong><br />
10.4 % (14). Sensitization <strong>of</strong> mesoporous TiO2<br />
us<strong>in</strong>g N719 dyes can <strong>in</strong>crease photocurrent action<br />
spectra compared with mesoporous<br />
TiO2//am<strong>in</strong>osilyl-Co II -pyridilazoresorc<strong>in</strong>ol (Fig 2c).<br />
This report proves that anchor<strong>in</strong>g <strong>of</strong> carboxylic<br />
group more favour than silyl group, except <strong>of</strong> metal<br />
ion and ligand <strong>in</strong>fluence. Further explanation need<br />
observation <strong>of</strong> two dyes with the equivalent metal<br />
ions and ligand.<br />
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<strong>The</strong> photovoltaic performance <strong>of</strong> DSSCs<br />
depends largely on the film thickness (12). Wei et.<br />
al. (12) have showed Jsc <strong>of</strong> the cells composed <strong>of</strong><br />
mesoporous TiO2 and P-25 <strong>in</strong>itially <strong>in</strong>creased with<br />
film thickness but then fell <strong>of</strong>f with further<br />
<strong>in</strong>creases <strong>in</strong> thickness. <strong>The</strong> film thickness<br />
approximately 20 µm for the mesoporous TiO2 film<br />
and that for the P-25 film is fix<strong>in</strong>g with sealant used<br />
as spacer between work<strong>in</strong>g electrode and counter<br />
electrode. On the other hand, the electron<br />
recomb<strong>in</strong>ation between the electrons <strong>in</strong>jected from<br />
the excited dye to the conduction band <strong>of</strong> electrode<br />
TiO2 and the I3 - ions <strong>in</strong> the electrolyte becomes<br />
more serious <strong>in</strong> the thicker films. It should be<br />
po<strong>in</strong>ted out that this IPCE tendency <strong>of</strong> the cells<br />
made <strong>of</strong> P-25 less than those <strong>of</strong> mesoporous TiO2,<br />
<strong>in</strong>dicat<strong>in</strong>g that the electron recomb<strong>in</strong>ation between<br />
the transported electrons and I3 - ions <strong>in</strong> the P-25<br />
film is more serious than that <strong>in</strong> the mesoporous<br />
TiO2 film (Fig 2). This may contribute to the<br />
differences <strong>in</strong> electrode material morphology. As<br />
mentioned above, the particle size <strong>of</strong> P-25 is<br />
approximately 20 nm, while mesoporous TiO2 has a<br />
short-range ordered-framework structure and a<br />
smaller particle size (approx. 7–8 nm, calculated by<br />
Scherrer equation from Fig. 8), and thus conta<strong>in</strong>s a<br />
large number <strong>of</strong> gra<strong>in</strong> boundaries <strong>of</strong> homogeneous<br />
nanocrystall<strong>in</strong>e TiO2 along the framework (Fig.5).<br />
Nakade et al.(18,19) report that the diffusion<br />
coefficients <strong>of</strong> electrons <strong>in</strong>creased with TiO2<br />
particle size. <strong>The</strong> <strong>in</strong>creas<strong>in</strong>g diffusion coefficients<br />
<strong>of</strong> electrons were related to the decreased film<br />
surface area and the condition <strong>of</strong> the gra<strong>in</strong><br />
boundaries. On the other hand, they also found that<br />
the electron lifetimes decreased with <strong>in</strong>creas<strong>in</strong>g<br />
TiO2 particle size. <strong>The</strong>refore, an electrode film<br />
composed <strong>of</strong> mesoporous TiO2 is conductive to<br />
decreased diffusion coefficients <strong>of</strong> electrons and<br />
<strong>in</strong>creased electron lifetimes.<br />
Fig. 5. SEM picture <strong>of</strong> mesoporus TiO2 synthesized<br />
by Pluronic P123 templated at molar ratio <strong>of</strong><br />
TTIP/P123/acac/H2O/IPr =<br />
1/0,051/0,53/12/30 (a) magnitification<br />
50.000x (b) magnitification 95.000x, and<br />
SEM picture <strong>of</strong> TiO2 P25 at (a)<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
magnitification 50.000x (d) magnitification<br />
90.000x<br />
Fig.6. SEM photograph <strong>of</strong> cross section <strong>of</strong><br />
ITO/mesoporousTiO2. <strong>The</strong> ITO/meso<br />
porous TiO2 film was calc<strong>in</strong>ated at 400 o C<br />
for 2 hour.<br />
Fig 6. Illustration <strong>of</strong> mesoporous TiO2 <strong>in</strong> 30 nm<br />
average pore diameter size with numerous<br />
uniform am<strong>in</strong>osilyl nanochannels.<br />
Am<strong>in</strong>osilyl nanochannels absorb monolayer<br />
dyes<br />
Our experimental results suggest that the<br />
mesoporous structure plays a key role and is<br />
responsible for the improvement <strong>in</strong> the performance<br />
parameters. Compared with P-25 nanoparticles,<br />
mesoporous TiO2 has numerous uniform am<strong>in</strong>osilyl<br />
nanochannels 30 nm <strong>in</strong> average pore size (Fig 6).<br />
Assum<strong>in</strong>g that the adsorbed dye forms a monolayer<br />
on the <strong>in</strong>ner surfaces <strong>of</strong> the am<strong>in</strong>osilyl<br />
nanochannels, and the molecular size <strong>of</strong> PAR as<br />
organic ligand is approximately 1.20 Å nm - 2.4 Å<br />
(24), big space is left for electrolyte diffusion. If the<br />
adsorbed dye molecules were stuck <strong>in</strong> the <strong>in</strong>ner<br />
surface <strong>of</strong> the channels as a bilayer or aggregated <strong>in</strong><br />
the entrances <strong>of</strong> the nanochannels, the space for<br />
electrolyte diffusion will not further reduced. Under<br />
these conditions, it only need short time for the<br />
electrolyte solution to penetrate and fill all the<br />
nanochannels. Us<strong>in</strong>g a little dye <strong>of</strong> Co 2+ complexes<br />
the aggregated adsorption dye molecules <strong>in</strong> the<br />
entrances <strong>of</strong> the nanochannels can not hampers dye<br />
adsorption on the <strong>in</strong>ner surface <strong>of</strong> the<br />
nanochannels. Based on the assumptions mentioned<br />
above, part <strong>of</strong> the <strong>in</strong>ner surface is be covered by<br />
dye molecules and the electrode film can be used<br />
efficiently. However, over time, the rearrangement<br />
<strong>of</strong> adsorbed dye might occur accompanied with the<br />
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diffusion <strong>of</strong> electrolyte solution. On the other hand,<br />
due to anchor<strong>in</strong>g group addition cooperated <strong>in</strong> TiO2<br />
surface as well as <strong>in</strong> Co 2+ -pyridilazoresorc<strong>in</strong>ol<br />
complexes, remov<strong>in</strong>g dye together with<strong>in</strong><br />
electrolyte can be reduced. But am<strong>in</strong>osilyl<br />
nanochannels with high concentration may <strong>in</strong>crease<br />
cell resistivity due to silyl condensation.<br />
<strong>The</strong> XRD pattern <strong>of</strong> mesoporous TiO2<br />
synthesized by self assembly-sol gel method<br />
adopted followed previous work (19) was shown <strong>in</strong><br />
Fig. 7. It can be seen that the phase <strong>of</strong> mesoporous<br />
TiO2 annealed at 400 o C show well-crystallized both<br />
anatase (90%) and rutile (10%) peak. <strong>The</strong> average<br />
crystal size <strong>of</strong> TiO2 calculated us<strong>in</strong>g the Scherer<br />
equation is about 7 nm.<br />
Fig. 7. X-ray diffraction pattern <strong>of</strong> TiO2 th<strong>in</strong> film<br />
on <strong>in</strong>dium t<strong>in</strong> oxide glass. Synthesized at<br />
molar ratio <strong>of</strong> P123/acac/HCl/H2O/iPr =<br />
0.05:0.53:1.25:12.00:30.00.<br />
Clean up <strong>of</strong> template occur at 400 o C, due to<br />
organic group burn<strong>in</strong>g at that temperature. <strong>The</strong>se<br />
phenomena show at <strong>in</strong>fra red spectra’s (Fig. 9),<br />
differential thermal analysis (Fig. 10a.) and<br />
thermograph metric analysis (Fig.10b.).<br />
Fig 9. Infra red spectra <strong>of</strong> TiO 2 annealed at (a) 150 o C, (b)<br />
300 o C, and (c) 400 o C.<br />
M icrovolt Endo up (m icrovolt)<br />
W eight % (% )<br />
400<br />
350<br />
300<br />
250<br />
200<br />
150<br />
100<br />
50<br />
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0<br />
0 100 200 300 400 500 600 700 800<br />
100<br />
80<br />
60<br />
40<br />
20<br />
Temperature (C)<br />
0<br />
0 200 400 600 800<br />
Temperature (C)<br />
Fig.10. <strong>The</strong>rmal analysis <strong>of</strong> TiO2 xerogel (a)<br />
differential thermal analysis, and (b)<br />
thermographymetric analysis<br />
We report here a novel dyes, cobalt-based<br />
photosensitizer, was prepared via <strong>in</strong> situ complexes<br />
formation. <strong>The</strong> UV Vis spectra <strong>of</strong> Co 2+ , Co 2+ -APTS<br />
complexes, and Co 2+ -APTS-PAR complexes <strong>in</strong><br />
methanol show <strong>in</strong> Fig. 11. It exposed that visible<br />
absorption <strong>of</strong> Co 2+ -APTS-PAR complexes is very<br />
far above the ground due to chromophore ligand <strong>of</strong><br />
4-(2-piridylazo)resorc<strong>in</strong>ol. <strong>The</strong> specular absorption<br />
spectra <strong>of</strong> the TiO2 sample show <strong>in</strong> Fig. 11a. <strong>The</strong><br />
band gap <strong>of</strong> the anatase crystal as calculated for the<br />
absorption edge <strong>in</strong> the visible region was found to<br />
be 3.02 eV, respectively. This result is appropriate<br />
with Eg value <strong>of</strong> TiO2 anatase and rutile literatures<br />
about 2.99 – 3.32 eV (20, 21, 22). <strong>Addition</strong> <strong>of</strong><br />
anchor<strong>in</strong>g ligand <strong>of</strong> APTS, and Co 2+ complexes can<br />
move absorption spectra at visible region slightly<br />
(Fig 12c).<br />
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January 24, 2009<br />
Fig 11. UV VIS spectra’s <strong>of</strong> (a) Co 2+ ion <strong>in</strong><br />
methanol solution, (b) Co 2+ -APTS<br />
complexes solution <strong>in</strong> methanol, and (c)<br />
Co 2+ -APTS-PAR complexes <strong>in</strong> methanol<br />
Fig 12. UV VIS spectras <strong>of</strong> (a) TiO2 film onto ITO<br />
glass, (b) am<strong>in</strong>osilane-TiO2 film onto<br />
ITO glass, and (c) am<strong>in</strong>osilane-TiO2/dye<br />
film onto ITO glass<br />
High absorption spectra at ultraviolet region,<br />
shown <strong>in</strong> Fig. 12, exhibits one pyridyl based ð-ð*<br />
transition (245 nm) and one metal-to-ligand charge<br />
transfer (MLCT) bands at 550 nm superimposed<br />
with weakly d-d transition. Like those <strong>of</strong> bipyridyl<br />
complexes <strong>of</strong> ruthenium(II), their <strong>in</strong>tense visible<br />
absorptions are due to excitation <strong>in</strong>to <strong>in</strong>itially<br />
s<strong>in</strong>glet metal-to-ligand charge transfer (1MLCT)<br />
states via t2g ð* electronic transitions. However,<br />
cobalt’s weaker ligand field places the metalcentered<br />
antibond<strong>in</strong>g eg orbitals lower <strong>in</strong> energy<br />
than the ligand ð* orbitals. As a consequence,<br />
unlike ruthenium complexes, for which a 3 MLCT<br />
state is populated via <strong>in</strong>tersystem cross<strong>in</strong>g and<br />
persists for nano - to microseconds, cobalt<br />
complexes crossover to a ligand field (LF) state.<br />
<strong>The</strong>re is a concurrent and substantial loss <strong>of</strong> excited<br />
state energy: for the tris-substituted complexes, the<br />
LF state is only 0.9 eV above the ground state (23).<br />
Conclusion<br />
An improvement photocurrent action spectrum<br />
was achieved by apply<strong>in</strong>g anchored-mesoporous<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
TiO2 as an electrode material. This high efficiency<br />
can be attributed to the novel physicochemical<br />
properties <strong>of</strong> mesoporous TiO2, which <strong>in</strong>clude high<br />
surface area, uniform nanochannels and a<br />
homogeneous nanocrystall<strong>in</strong>e TiO2 several nm <strong>in</strong><br />
size arranged along the framework. <strong>The</strong> high<br />
surface area anchored-TiO2 allows adsorption <strong>of</strong> a<br />
large volume <strong>of</strong> dye, result<strong>in</strong>g <strong>in</strong> a higher <strong>in</strong>cident<br />
photon to current efficiency. <strong>The</strong> photovoltaic<br />
performance <strong>of</strong> the dye-sensitized solar cells<br />
composed <strong>of</strong> mesoporous TiO2 is expected to be<br />
further improved through the use anchor group,<br />
which has higher thermal stability. <strong>The</strong>refore,<br />
mesoporous TiO2, used as an electrode material <strong>in</strong><br />
DSSCs, may provide a means <strong>of</strong> obta<strong>in</strong><strong>in</strong>g higher<br />
efficiencies <strong>in</strong> dye sensitized solar cells, possibly<br />
approach<strong>in</strong>g their theoretical efficiency value <strong>in</strong><br />
future.<br />
Acknowledgements<br />
This work was supported by M<strong>in</strong>ister <strong>of</strong><br />
Education <strong>of</strong> Indonesia under Sandwich Program<br />
2008 visit<strong>in</strong>g <strong>in</strong> ARC Centre <strong>of</strong> Excellence for<br />
Functional Nanomaterials, Australian Institute for<br />
Bioeng<strong>in</strong>eer<strong>in</strong>g and Nanotechnology, University <strong>of</strong><br />
Queensland.<br />
References<br />
1. B. O’Regan and M. Grätzel, 1991, A Low cost,<br />
high efficiency solar cell based on dye<br />
sensitized colloidal TiO2 film, Nature, 353,<br />
737-739.<br />
2. M. Gratzel, 2001, Photoelectrochemical cell,<br />
414, 334-338.<br />
3. P. Ravirajan, S.A. Haque, J.R. Darrant, D.<br />
Poplauskyy, D.D.C. Bradley, J. Nelson, 2004,<br />
Hybrid nanocrystall<strong>in</strong>e TiO2 solar cell with a<br />
fluor<strong>in</strong>e-thiophene copolymer as a sensitizer<br />
and hole conductor.<br />
4. J.Li, T. Ossasa, Y. Hirayama, T. Sano, K.<br />
Wakisaka, M. Matssumura., 2006, Solid state<br />
dye sensitized solar cell us<strong>in</strong>g poly(2-methoxy-<br />
5-(2-ethylhexyloxy)-1,4-phenylene-v<strong>in</strong>ylene)<br />
as a hole-transport<strong>in</strong>g material, 45, 11, 8728-<br />
8732.<br />
5. S. Tan, J. Zhai, M. Wan, Q. Meng, Y. Li, L.<br />
Jiang, Daoben Zhau, 2004, Influence <strong>of</strong> small<br />
moleculs <strong>in</strong> conduct<strong>in</strong>g polyanil<strong>in</strong>e on the<br />
photovoltaic properties <strong>of</strong> solid state dye<br />
sensitized solar cell, J. Phys. Chem., B., 108,<br />
18693-18697.<br />
6. P.R. Somari, S.P. Somani, M. Umeno, 2006,<br />
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Applied Physics Letters, 89, 083501.<br />
7. Z.S. Wang, H. Kawauchi, T. Kashima,<br />
H.Arakawa , 2004, Significant <strong>in</strong>fluence <strong>of</strong><br />
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conversion efficiency <strong>of</strong> N719 dye-sensitized<br />
solar cell, Coord<strong>in</strong>ation Chemistry Reviews,<br />
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8. P. Wachter, M. Zistler, C. Schre<strong>in</strong>er, M.<br />
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Wasserscheid, A.H<strong>in</strong>sch, H. J. Gores, 2008,<br />
Characterisation <strong>of</strong> DSSC-electrolytes based<br />
on 1-ethyl-3-methylimidazolium dicyanamide:<br />
Measurement <strong>of</strong> triiodide diffusion coefficient,<br />
viscosity, and photovoltaic performance,<br />
Journal <strong>of</strong> Photochemistry and Photobiology<br />
A: Chemistry 197, 25–33<br />
9. A. Kay, M. Gratzel, 1996, Low cost<br />
photovoltaic modules based on dye sensitized<br />
nanocrystall<strong>in</strong>e titanium dioxide and carbon<br />
powder, Solar Energy Materials and Solar<br />
Cells, 44 99-117.<br />
10. A. Hauch, A. Georg , 2001, Diffusion <strong>in</strong> the<br />
electrolyte and charge transfer reaction at the<br />
plat<strong>in</strong>um electrode <strong>in</strong> dye-sensitized solar cells,<br />
Electrochimica Acta, 46, 3457–3466.<br />
11. M. Grätzel, 2004, Conversion <strong>of</strong> sunlight to<br />
electric power by nanocrystall<strong>in</strong>e dyesensitized<br />
solar cells,_Journal <strong>of</strong><br />
Photochemistry and Photobiology A:<br />
Chemistry, 164 3–12. M. Wei, Y. Konishi, H.<br />
Zhou, M. Yanagida, H.Sugihara and H.<br />
Arakawa, 2006, Highly efficient dye-sensitized<br />
solar cells composed <strong>of</strong> mesoporous titanium<br />
dioxide, Journal <strong>of</strong> Materials chemistry, J.<br />
Mater. Chem., 16, 1287–1293.<br />
12. M.K. Nazeerudd<strong>in</strong>, A.Kay, I. Rodicio, R.<br />
Humphry-Baker, E.Muller, P. Liska, N.<br />
Vchopoulus, and M. Gratzel, 1993, Convertion<br />
<strong>of</strong> Ligh to Electricity by cis-X2Bis(2,2’bipyridyl-4,4’-dicarboxylate)ruthenium(II)<br />
charge-transfer sensitizers (X= Cl-, Br-, I-,<br />
CN-, and SCN-) on nanocrystal<strong>in</strong>e TiO2<br />
electrodes, J.Am.Chem.Soc, 115, 6382-6390.<br />
13. M.K. Nazeerudd<strong>in</strong>, P. Pe´chy, T. Renouard,<br />
S.M. Zakeerudd<strong>in</strong>, R. Humphry-Baker,<br />
P.Comte, P.Liska, L. Cevey, E. Costa.<br />
V.Shklover,. L.Spiccia,. G. B. Deacon, C.A.<br />
Bignozzi, and M.Gra1tzel, 2001, Eng<strong>in</strong>eer<strong>in</strong>g<br />
<strong>of</strong> Efficient Panchromatic Sensitizers for<br />
Nanocrystall<strong>in</strong>e TiO2-Based Solar Cells, J.<br />
Am. Chem. Soc., 123, 1613-1624.<br />
14. K. Suzuki, M. Yamaguchi, M. Kumagai, and<br />
S. Yanagiday, 2003, Application <strong>of</strong> Carbon<br />
Nanotubes to Counter Electrodes <strong>of</strong> Dyesensitized<br />
Solar Cells, Chemistry Letters<br />
Vol.32, No.1, 28-29.<br />
15. A.F. Nogueira, J. R. Durrant, and M. A. De<br />
Paoli, 2001, Dye-Sensitized Nanocrystall<strong>in</strong>e<br />
Solar Cells, Employ<strong>in</strong>g a Polymer Electrolyte,<br />
Adv. Mater., 13, No. 11, 826-830<br />
16. P. Wang, S. M. Zakeerudd<strong>in</strong>, J. E. Moser,<br />
M.K. Nazeerudd<strong>in</strong>, T. Sekiguchi and M.<br />
Grätzel , 2003, A stable quasi-solid-state dye-<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
sensitized solar cell with an amphiphilic<br />
ruthenium sensitizer and polymer gel<br />
electrolyte, nature materials, vol 2, 402-408.<br />
17. S. Nakade, T.Kanzaki, W.Kubo, T.Kitamura,<br />
Y.Wada, S.Yanagida, 2005, Role <strong>of</strong><br />
electrolytes on charge recomb<strong>in</strong>ation <strong>in</strong> dyesensitized<br />
TiO2 solar cell (1): the case <strong>of</strong> solar<br />
cell us<strong>in</strong>g the I - /I3 - redox couple, J. Phys Chem<br />
B Condens Matter Mater surf Interface<br />
Biophys., 109(8), 3480-3487.<br />
18. S. Yanagida, S. Nakade, Y. Saito, W. Kubo, T.<br />
Kitamura, and Y. Wada, Charge transport and<br />
optimization for dye-sensitized nano-porous<br />
TiO2 solar cells, Material and Life Science,<br />
Graduate School <strong>of</strong> Eng<strong>in</strong>eer<strong>in</strong>g, Osaka<br />
University Suita, Osaka 565-0871, Japan.<br />
19. Yun, H., Miyazawa, K., Honma, I., Zhou, H.,<br />
Kuwabara, M., 2003, Syntesis <strong>of</strong><br />
Semicrystallized Mesoporous TiO2 Th<strong>in</strong> Fims<br />
us<strong>in</strong>g Triblock Copolymer Templates,<br />
Materials Science and Eng<strong>in</strong>er<strong>in</strong>g C, 23, 487-<br />
494.<br />
20. Li, Y., Hagen, J., Schaffrath, W., Otsckik, P.,<br />
Haaner, D., 1999, “Titanium dioxide Films for<br />
Photovoltaic Cells Derived from a Sol gel<br />
Process”, Solar Energy and Solar Cells, 56,<br />
167-174.<br />
21. Castillo, N., Olgu´ın, D., Conde-Gallardo, A.,<br />
2004, Structural and morphological properties<br />
<strong>of</strong> TiO2 th<strong>in</strong> films prepared by spray pyrolysis,<br />
REVISTA MEXICANA DE F´ISICA, 50 (4),<br />
382–387.<br />
22. Janczarek, M., Kisch, H., Hupka, J., 2007,<br />
Photoelectrochemical characterization <strong>of</strong><br />
nitrogen-modified TiO2, Physicochemical<br />
Problems <strong>of</strong> M<strong>in</strong>eral Process<strong>in</strong>g, 41, 159-166.<br />
23. J.T. Hupp and Y.Dong, 1994, Intervalence<br />
energy effect accompany<strong>in</strong>g double crown<br />
encapsulation <strong>of</strong> the Creutz-Taube ion; an<br />
<strong>in</strong>terpretation based on three site mix<strong>in</strong>g,<br />
Inorg. Chem., 33 4421-4424.<br />
24. H. Groenz<strong>in</strong>, O.C. Mull<strong>in</strong>s, Petroleum<br />
asphaltene molecular size and structure,<br />
Schlumberger-Doll Research, 728-732<br />
25. A. Hagfeldt, M. Gratzel, 1995, Ligh-<strong>in</strong>duced<br />
redox reactions <strong>in</strong> nanocrystall<strong>in</strong>e systems,<br />
Chem. Rev., 95, 49-68.<br />
26. L. Schmidt-Mende, J. E. Kroeze, J.R. Durrant,<br />
Md. K. Nazeerudd<strong>in</strong>, M. Gratzel, 2005, Effect<br />
<strong>of</strong> hydrocarbon cha<strong>in</strong> length <strong>of</strong> amphiphilic<br />
ruthenium dyes on solid-state dye sensitized<br />
photovoltaic, NANO LETTER, 5, 7, 1315-<br />
1320.<br />
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Introduction<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
Synthesis and Characterization Of PVA/Montmorillonite<br />
Khoirul Himmi Setiawan 1 , Is Fatimah 2<br />
1 Research and Development Unit for Biomaterials LIPI, Bogor, Indonesia,<br />
Email: khoirul_himmi@yahoo.com<br />
2 Chemistry Dept., Islamic University <strong>of</strong> Indonesia, Yogyakarta, Indonesia,<br />
Email: isfatimah@fmipa.uii.ac.id<br />
Abstract<br />
Polyv<strong>in</strong>yl alcohol (PVA)/montmorillonite composites were prepared by <strong>in</strong>tercalation <strong>in</strong> solution<br />
system. <strong>The</strong>ir physicochemical properties as the function <strong>of</strong> PVA to montmorillonite mass ratio were<br />
<strong>in</strong>vestigated with X-ray diffraction (XRD), surface area analyzer and Fourier Transform Infra Red. <strong>The</strong><br />
results showed that PVA cha<strong>in</strong>s could be <strong>in</strong>tercalated <strong>in</strong>to the silica <strong>in</strong>terlayer space <strong>of</strong> montmorillonite<br />
and the properties are affected by the PVA to montmorillonite mass ratio. Due to FTIR and surface area<br />
analyzer data, it can be concluded that there are no significant surface properties <strong>of</strong><br />
PVA/montmorillonite with<strong>in</strong> the range <strong>of</strong> 1% to 3% w.t clay content. However, the XRD pattern <strong>of</strong><br />
materials show the effect <strong>of</strong> the mass ratio <strong>in</strong> that the highest d 001 produced at the ratio <strong>of</strong> 1% PVA <strong>in</strong><br />
the PVA/montmorillonite synthesis. <strong>The</strong>se data are the <strong>in</strong>dication <strong>of</strong> <strong>in</strong>tercalation process to exfoliat<strong>in</strong>g<br />
process as the PVA concentration <strong>in</strong>crease controlled by the cation exchange capacity.<br />
Keywords: <strong>in</strong>tercalation, montmorillonite, PVA/Montmorillonite<br />
Nanocomposite materials, consist<strong>in</strong>g <strong>of</strong> <strong>in</strong>organic<br />
nanolayers <strong>of</strong> montmorillonite (MMT) clay and organic<br />
polymers, have evoked <strong>in</strong>tense <strong>in</strong>terest lately because<br />
their unique characteristics have the potential to be used<br />
<strong>in</strong> many commercial applications. Nanostructured<br />
polymer-<strong>in</strong>organic composites, mixed at the molecular<br />
level or near molecular level, are much different from<br />
the conventional composites with <strong>in</strong>corporation <strong>of</strong> a<br />
variety <strong>of</strong> additives <strong>in</strong> the polymer matrices. In the<br />
polymer-<strong>in</strong>organic nanocomposites, strong chemical<br />
bonds or <strong>in</strong>teractions such as van der Waals forces,<br />
hydrogen bond<strong>in</strong>g, or electrostatic forces, <strong>of</strong>ten exist<br />
between the polymer and <strong>in</strong>organic components (Jung<br />
et al., 2006).<br />
Several useful polymer/clay nanocomposite<br />
materials have been produced. At present, polymer/clay<br />
hybrids are one <strong>of</strong> the most important classes <strong>of</strong><br />
synthetically eng<strong>in</strong>eered materials. <strong>The</strong>y can be<br />
transformed <strong>in</strong>to new materials possess<strong>in</strong>g the<br />
advantages <strong>of</strong> both organic materials, such as light<br />
weight, flexibility, and good moldability, and <strong>in</strong>organic<br />
materials, such as high strength, heat stability, and<br />
chemical resistance (Chang et al., 2003). <strong>The</strong> flexibility<br />
and processability <strong>of</strong> polymer matrices based on watersoluble<br />
polymer such as poly-v<strong>in</strong>yl alcohol (PVA) with<br />
excellent optical properties and good compatibility with<br />
additives can provide good mechanical properties.<br />
Poly-v<strong>in</strong>yl alcohol (PVA) is a water-soluble<br />
polymer extensively used <strong>in</strong> paper coat<strong>in</strong>g, textile<br />
siz<strong>in</strong>g, and flexible water-soluble packag<strong>in</strong>g films.<br />
<strong>The</strong>se applications stimulate <strong>in</strong>terest <strong>in</strong> improv<strong>in</strong>g the<br />
mechanical, thermal, and permeability properties <strong>of</strong> th<strong>in</strong><br />
nanocomposite films, ultimately with the hope <strong>of</strong><br />
reta<strong>in</strong><strong>in</strong>g the optical clarity <strong>of</strong> PVA (Strawhecker &<br />
Manias, 2000). PVA nanocomposite materials may<br />
<strong>of</strong>fer a viable alternative for these applications to heat<br />
treatments or conventionally filled PVA materials. <strong>The</strong><br />
flexibility and processability <strong>of</strong> polymer matrices based<br />
on water-soluble polymer such as poly-v<strong>in</strong>yl alcohol<br />
(PVA) with excellent optical properties and good<br />
compatibility with additives can provide good<br />
mechanical properties. <strong>The</strong>re are several publications<br />
associated with the preparation and properties <strong>of</strong><br />
PVA/clay nanocomposites prepared by solution<br />
dispersion technique (Carrado et al.,1996, Wang &<br />
Wu, 1997, Strawhecker & Manias, 2000).<br />
Recently, PVA/clay nanocomposites are found to<br />
display novel properties, which can be observed from<br />
two dissimilar chemical components comb<strong>in</strong><strong>in</strong>g at the<br />
molecular level. Kokabi reported that nanocomposite<br />
hydrogels based on PVA and organically modified<br />
montmorillonite clay were <strong>in</strong>troduced as novel wound<br />
dress<strong>in</strong>gs, which prepared by the cyclic freez<strong>in</strong>g–<br />
thaw<strong>in</strong>g method. PVA/clay nanocomposite hydrogels<br />
showed excellent physical and mechanical properties<br />
which met the essential requirements <strong>of</strong> ideal wound<br />
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dress<strong>in</strong>gs. Based on swell<strong>in</strong>g measurements, they<br />
exhibited high capability <strong>in</strong> absorb<strong>in</strong>g fluid, so<br />
recommended for exudative wounds. Because <strong>of</strong> their<br />
unique mechanical properties, i.e. very high elasticity,<br />
they could be excellent candidates for wounds under<br />
high stresses. <strong>The</strong> proper values <strong>of</strong> the water vapor<br />
transmission rates <strong>of</strong> PVA nanocomposite hydrogels<br />
<strong>in</strong>dicated that they could keep moist environment on<br />
<strong>in</strong>terface <strong>of</strong> the wound and dress<strong>in</strong>g to accelerate the<br />
heal<strong>in</strong>g process (Kokabi, Sirousazar, & Hassan, 2007).<br />
And though many research about poly/clay have<br />
been reported, s<strong>in</strong>thesis and characterization <strong>of</strong><br />
nanocomposite hydrogels based on clay is not yet<br />
studied <strong>in</strong> Indonesia. With enormous clay resources,<br />
Indonesia need more advanced and susta<strong>in</strong>e research <strong>in</strong><br />
develop<strong>in</strong>g poly/clay, leads to some novel<br />
nanocomposites with improved performance properties,<br />
which may be potentially used <strong>in</strong> wide range application<br />
such as optics and biomedic<strong>in</strong>al technology. This paper<br />
will focus on review the unique structural properties <strong>of</strong><br />
PVA/Montmorillonite (MMT) clays made by<br />
<strong>in</strong>tercalation system. Physiochemical properties <strong>of</strong><br />
PVA/MMT will be analyzed by FT-IR, X ray<br />
diffractometer, and Surface Area Analyzer.<br />
Materials and Methods<br />
Experimental<br />
<strong>The</strong> start<strong>in</strong>g clay used for synthesis was natural<br />
montmorillonite supplied by PT. Tunas Inti Makmur<br />
Semarang, Indonesia. <strong>The</strong> cation exchange capacity <strong>of</strong><br />
clay is 68 meq/100 g. Particle sizes <strong>of</strong> less than 200<br />
mesh were used <strong>in</strong> synthesis process. Chemicals consist<br />
<strong>of</strong> H2SO4 and Poly-v<strong>in</strong>yl alcohol (PVA) was purchased<br />
from E.Merck.<br />
Synthesis <strong>of</strong> PVA-montmorillonite<br />
<strong>The</strong> start<strong>in</strong>g material, montmorillonite was dispersed <strong>in</strong><br />
water <strong>in</strong> the concentration <strong>of</strong> 10 % w.t and then refluxed<br />
with H2SO4 0.01 M for 6 hours <strong>in</strong> order to purify clay<br />
from impurities. Sample was filtered and neutralized<br />
until the filtrate was free from Cl - and pH=7. Solid was<br />
dried <strong>in</strong> oven at 130 o C followed by ground<strong>in</strong>g to 200<br />
mesh <strong>in</strong> particle size. PVA <strong>in</strong>tercalat<strong>in</strong>g solution was<br />
prepared by dilut<strong>in</strong>g PVA solution with deionized water.<br />
Clay suspension was made by dispers<strong>in</strong>g<br />
montmorillonite <strong>in</strong> water with the concentration <strong>of</strong> 5%<br />
w.t and stirred for 24 h. PVA <strong>in</strong>tercalation was<br />
performed by slow titration <strong>of</strong> a PVA solution <strong>of</strong> under<br />
vigorously stirr<strong>in</strong>g at room temperature for 24 hours.<br />
PVA concentrations were varied at 1, 2 and 3 w.t % clay<br />
content. After wash<strong>in</strong>g by centrifugation and filtration,<br />
the <strong>in</strong>tercalated solids were dried by heat<strong>in</strong>g <strong>in</strong> oven at<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
80 o C for 24 hours. Dry sample resulted was washed<br />
with aquadest. Further, PVA-clay composite are<br />
designated as PVA/MMT 1%, 2% and 3% respectively<br />
and for comparison purpose, montmorillonite clay<br />
encoded by MMT.<br />
Physiochemical characterisation <strong>of</strong> the samples was<br />
studied <strong>in</strong>clud<strong>in</strong>g surface area analysis (nitrogen<br />
adsorption at 77 K), X-ray diffraction (XRD), and<br />
Fourier Transform Infra Red (FT-IR) identification. Xray<br />
powder diffraction patterns were obta<strong>in</strong>ed by us<strong>in</strong>g a<br />
Shimadzu X6000 diffractometer, at 40 kV and 30 mA,<br />
and employ<strong>in</strong>g Ni filtered Cu Kα radiation<br />
Results and Discussion<br />
Material structure <strong>of</strong> Montmorillonit clay was identified<br />
by X-Ray Diffractmeter to study precursor effect from<br />
PVA toward physiochemical properties <strong>of</strong><br />
Montmorillonit. Figure 1 shows XRD curves <strong>of</strong><br />
Montmorillonit and PVA hybrids with different clays at<br />
1, 2 and 3 w.t % clay content. Wide-angle X-ray<br />
diffraction (XRD) measurements were performed at<br />
room temperature on a Shimadzu X6000 X-ray<br />
diffractometer us<strong>in</strong>g Ni filtered Cu Kα radiation. <strong>The</strong><br />
scann<strong>in</strong>g rate was 2°/m<strong>in</strong> over a range <strong>of</strong> 2θ = 3–25°.<br />
Figure 1. XRD patterns <strong>of</strong> (a) Montmorillonit<br />
(MMT) and (b)-(d) PVA/MMT 1%, 2% and<br />
3% respectively<br />
XRD pattern <strong>of</strong> MMT shows typical peak <strong>of</strong><br />
montmorillonite at 2θ = 5,9275 o (d = 14,898 Ǻ) and 2θ<br />
= 19,915 o (d = 4,454 Ǻ) with significant <strong>in</strong>tensity. Other<br />
typical peaks such as 2θ = 20,18 o and 2θ = 23,57 o ,<br />
confirm montmorillonite content. Compared to XRD<br />
pattern <strong>of</strong> Boyolali clay reported by Simpen et. al.<br />
(2003), the <strong>in</strong>tensity <strong>of</strong> typical peak from<br />
montmorillonite used <strong>in</strong> this study shows less<br />
crystall<strong>in</strong>e. Beside <strong>of</strong> montmorillonite typical peak,<br />
other m<strong>in</strong>eral content such as caol<strong>in</strong>ite showed at 2θ =<br />
12,2 o (d = 7,24Ă); 2θ = 24,86 o (d = 3,57 Å); and 2θ =<br />
19,88 o (d = 4,46 Å). Generally, XRD pattern showed<br />
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<strong>The</strong> First International Sem<strong>in</strong>ar on Science and Technology<br />
January 24, 2009<br />
that clay used <strong>in</strong> this research classified <strong>in</strong>to<br />
montmorillonite m<strong>in</strong>eral.<br />
<strong>The</strong> ma<strong>in</strong> basal spac<strong>in</strong>g (d001) peak reflections <strong>of</strong><br />
montmorillonte (MMT) are well def<strong>in</strong>ed, <strong>in</strong>dicat<strong>in</strong>g a<br />
very ordered structure. Figure 1 shows that <strong>in</strong>tercalation<br />
<strong>of</strong> PVA <strong>in</strong>to Montmorillonite cause basal spac<strong>in</strong>g<br />
displacement to the left along with the <strong>in</strong>creas<strong>in</strong>g <strong>of</strong> d001<br />
from PVA/MMT 1% w.t and PVA/MMT 2% w.t. In the<br />
presence <strong>of</strong> PVA, the peaks for both clays show the<br />
characteristics <strong>of</strong> a moderately disordered material,<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
<strong>in</strong>dicat<strong>in</strong>g the PVA presence <strong>in</strong> the <strong>in</strong>terlam<strong>in</strong>ar spaces<br />
though not throughout, s<strong>in</strong>ce if this were the case, the<br />
degree <strong>of</strong> disorder would be much greater. In other<br />
hand, PVA/MMT 3% w.t shows less d001 than<br />
Montmorillonite (MMT). This is caused by polymer<br />
graft<strong>in</strong>g which form agregrat <strong>in</strong> the <strong>in</strong>terlam<strong>in</strong>ar spaces<br />
<strong>of</strong> alum<strong>in</strong>osilicate structure. <strong>The</strong> data about <strong>in</strong>terlayer<br />
spac<strong>in</strong>gs <strong>of</strong> clay modified by PVA with various<br />
<strong>in</strong>tercalation agent concentration showed on table 1.<br />
Table 1. <strong>in</strong>terlayer spac<strong>in</strong>gs <strong>of</strong> Montmorillonit and PVA/MMT Nanocomposite<br />
SAMPLE 2 θ (FWHM) Basal spac<strong>in</strong>g d001<br />
MMT 6.30 14.47<br />
PVA/MMT 1% (w.t) 6.15 14.82<br />
PVA/MMT 2% (w.t) 6.06 15.04<br />
PVA/MMT 3% (w.t) 6.70 13.61<br />
Figure 2 shows the FT-IR spectrum for MMT,<br />
PVA hybrids with different clays at 1, 2 and 3 w.t %<br />
MMT content It is well known that pure MMT shows<br />
three strong peaks at 455, 520, and 1045 cm −1 . <strong>The</strong>se<br />
peaks are associated with the bend<strong>in</strong>g mode <strong>of</strong> Si-O,<br />
the stretch<strong>in</strong>g vibration <strong>of</strong> Al-O, and the stretch<strong>in</strong>g<br />
vibration <strong>of</strong> Si-O, respectively.<br />
Figure 2. FT-IR spectra <strong>of</strong> (a) MMT, (b) PVA/MMT 1%, (c) PVA/MMT 2%, (d) PVA/MMT 3%<br />
Sample Active Surface Area (m 2 /g)<br />
FT-IR spectrum all <strong>of</strong> the PVA/MMT<br />
nanocomposite microspheres show the presence <strong>of</strong><br />
the -OH stretch<strong>in</strong>g vibration <strong>in</strong> the region <strong>of</strong> 3000-<br />
3600 cm −1 after the <strong>in</strong>tercalation process. It <strong>in</strong>dicates<br />
that the surfaces <strong>of</strong> the PVA/MMT nanocomposite<br />
microsphere were covered with the hydroxyl groups.<br />
While FT-IR spectrum <strong>of</strong> PVA/MMT 3% show<br />
significant <strong>in</strong>tensity <strong>of</strong> alkyl typical peak (C–H sp 3 )<br />
on 2800 – 3000 cm -1 , other both PVA/MMT 1% and<br />
2% show no significant peak there.<br />
Table 2. Surface area <strong>of</strong> Montmorillonit and<br />
PVA/MMT<br />
MMT<br />
45,684<br />
PVA/MMT 1% (w.t)<br />
188.05<br />
PVA/MMT 2% (w.t)<br />
215.72<br />
PVA/MMT 3% (w.t)<br />
251.77<br />
Surface area <strong>of</strong> Montmorillonite (MMT), PVA<br />
hybrids with different clays at 1, 2 and 3 w.t % MMT<br />
content showed on table 2. It is obvious that specific<br />
surface area <strong>in</strong>crease along with the <strong>in</strong>crease <strong>of</strong> PVA<br />
concentration <strong>in</strong>tercalated. Information about the<br />
<strong>in</strong>fluence <strong>of</strong> PVA concentration toward <strong>in</strong>creas<strong>in</strong>g <strong>of</strong><br />
specific surface area can’t def<strong>in</strong>itely expla<strong>in</strong>e the<br />
physiochemical properties <strong>of</strong> material s<strong>in</strong>thesized. So,<br />
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January 24, 2009<br />
it needs more explanation about pore distribution<br />
presented on figure 3.<br />
Figure 3. Pore distribution <strong>of</strong> PVA/MMT hybrids<br />
material<br />
PVA/MMT 1% show formation <strong>of</strong> new specific<br />
pore at 32 Å (mesopore), while PVA/MMT 2% show<br />
no dom<strong>in</strong>ant pore formed. Preconception about the<br />
effect <strong>of</strong> polymer graft<strong>in</strong>g which form agregrat <strong>in</strong> the<br />
<strong>in</strong>terlam<strong>in</strong>ar spaces <strong>of</strong> alum<strong>in</strong>osilicate structure is<br />
confirmed by formation <strong>of</strong> two k<strong>in</strong>d dom<strong>in</strong>ant pore<br />
mode from PVA/MMT 3%, around 32 Å dan 56Å. It<br />
can be assumed that there is graft<strong>in</strong>g structure<br />
form<strong>in</strong>g clay layer aggregation which is responsible<br />
to form mesopore.<br />
Conclusion<br />
PVA <strong>in</strong>tercalation <strong>in</strong>to montmorilonite structure<br />
to form PVA/MMT composite shown the effect <strong>of</strong><br />
PVA precentage <strong>in</strong> composite to the physicochemical<br />
characters <strong>of</strong> materials. From the XRD and surface<br />
area analysis data it is concluded that the<br />
<strong>in</strong>tercalation with 1% and 2% PVA give the clay<br />
structure <strong>in</strong>tercalation followed by <strong>in</strong>creas<strong>in</strong>g spesific<br />
surface area <strong>of</strong> materials. <strong>The</strong>se physicochemical<br />
character ga<strong>in</strong>ed graft<strong>in</strong>g structure by the use PVA <strong>of</strong><br />
3% as revealed by XRD, pre distribution analysis and<br />
FTIR analysis.<br />
References<br />
Carrado, K. A., Thiyagarajan, P., & Elder, D. L.<br />
(1996). Clays Clay M<strong>in</strong>er,44 , 506.<br />
Chang, J. H., Jang, T. G., Ihn, K. J., Lee, W. K., &<br />
Sur, G. S. (2003). Journal <strong>of</strong> Applied Polymer<br />
Science, 90 , 3208–3214.<br />
Jung, H. M., Lee, E. M., Ji, B. C., Sohn, S. O., Ghim,<br />
H. D., Cho, H., et al. (2006). Fibers and<br />
Polymers, 7 , 229-234.<br />
Kokabi, M., Sirousazar, M., & Hassan, Z. M. (2007).<br />
European Polymer Journal,43 , 773–781.<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
Strawhecker, K. E., & Manias, E. (2000). Chem<br />
Mater, 12 , 2943.<br />
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January 24, 2009<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
Structure and Characterizations TiO2/TS-1 with Variation <strong>of</strong><br />
Calc<strong>in</strong>ation Temperature<br />
Maria Ulfa * Didik Prasetyoko<br />
Chemistry Department <strong>of</strong> Mathematic and Science Faculty<br />
Institut Teknologi Sepuluh Nopember<br />
Surabaya<br />
* e-mail: mariaulfa8@gmail.com<br />
Abstract<br />
Cathechol and hidroqu<strong>in</strong>on are used <strong>in</strong> a broad range application from pharmaceuticals,<br />
photography to polimer <strong>in</strong>dustries. Cathechol and hidroqu<strong>in</strong>on can be synthesized from<br />
phenol hydroxylation with H2O2 as oxidant and Titanium Silicalite (TS-1) as catalyst. TS-1<br />
has great properties, such as high activity and selectivity to oxidation reaction. However, its<br />
hydrophobic site leads to slow H2O2 adsorption toward the active site <strong>of</strong> TS-1.<br />
Consequently, the reaction rate <strong>of</strong> whole reaction is low. Titanium oxide (TiO2) as metal<br />
oxide can give acid site to catalysts. TiO2 has acidic properties, which is depend on<br />
calc<strong>in</strong>ation temperature due to phases transformation <strong>of</strong> anatase-rutile. In this research,<br />
<strong>The</strong> TiO2 is impregnated <strong>in</strong>to TS-1 then its prepared with variation <strong>of</strong> calc<strong>in</strong>ation<br />
temperature. <strong>The</strong> novel catalyst, TiO2/TS-1, will be more hydrophilic at certa<strong>in</strong> calc<strong>in</strong>ation<br />
temperature compared to TS-1 and rate <strong>of</strong> the hydroxylation phenol reaction will be faster.<br />
Keywords: TiO2/TS-1, hydroxylation <strong>of</strong> phenol, calc<strong>in</strong>ation temperature<br />
Introduction<br />
Cathechol and hidroqu<strong>in</strong>on are used <strong>in</strong> a large application<br />
<strong>of</strong> the modern chemical <strong>in</strong>dustry such us pharmaceuticals,<br />
photography to polimer <strong>in</strong>dustries (1). TS-1 which was<br />
firest synthesized by Taramasso et al <strong>in</strong> 1983 has shown<br />
excellent catalytic activity <strong>in</strong> organic oxidation reactions<br />
us<strong>in</strong>g hydrogen peroxide as oxidant under mild conditions.<br />
In organic oxidation reactions such us hydroxylation<br />
phenol, many work have been done to enhance the the<br />
phenol selectivity due to the <strong>in</strong>dustrial importance <strong>of</strong><br />
hydroxylation <strong>of</strong> phenol <strong>in</strong> the synthesis hydroqu<strong>in</strong>one and<br />
cathechol. <strong>The</strong> ability <strong>of</strong> TS-1 to catalyze a wide variety <strong>of</strong><br />
oxidation transformation <strong>in</strong>clud<strong>in</strong>g hydroxylation <strong>of</strong> phenol<br />
with aqueous hydrogen peroxide had led to extensive<br />
research worldwide on the synthesis <strong>of</strong> related heterogenous<br />
catalyst for liquid phase oxidations (2)<br />
<strong>The</strong> catalytic activity <strong>of</strong> TiO2 is strongly<br />
<strong>in</strong>fluenced by its structure. TiO2 is usually obta<strong>in</strong>ed<br />
by hydrolysis <strong>of</strong> titanium oxide, followed by<br />
anneal<strong>in</strong>g <strong>in</strong> the presence <strong>of</strong> oxygen. Porter et al. [3]<br />
studied microstructural changes <strong>in</strong> commercial<br />
Degussa P-25 TiO2 due to heat-treatment. <strong>The</strong><br />
powder was annealed from 600 to 1000 °C. With the<br />
<strong>in</strong>creas<strong>in</strong>g calc<strong>in</strong>ation temperature the apparent<br />
crystallite size and rutile content <strong>in</strong> the catalyst<br />
<strong>in</strong>creased, whereas the specific surface area and the<br />
rate <strong>of</strong> phenol photodecomposition under UV<br />
irradiation decreased. <strong>The</strong> same effect was observed<br />
by Reddy et al. [4] for catalytic activity obta<strong>in</strong>ed by<br />
TiCl4 hydrolysis and calc<strong>in</strong>ation at low temperatures,<br />
between 100 and 600 °C. A marked <strong>in</strong>crease <strong>in</strong> the<br />
crystallite size and a decrease <strong>in</strong> lattice stra<strong>in</strong> were<br />
observed for catalysts annealed above 600 °C. <strong>The</strong><br />
rate <strong>of</strong> methylene blue degradation <strong>in</strong> UV <strong>in</strong>creased<br />
with <strong>in</strong>creas<strong>in</strong>g calc<strong>in</strong>ation temperature from 400 to<br />
700 °C. Calc<strong>in</strong>ation above 700 °C resulted <strong>in</strong> a<br />
smaller rate constant, ma<strong>in</strong>ly due to partial<br />
transformation <strong>of</strong> anatase to rutile. <strong>The</strong> catalytic<br />
activity <strong>of</strong> the titanium oxide is related ma<strong>in</strong>ly to its<br />
acid properties. Some author have reported that the<br />
catalyst conta<strong>in</strong> Lewis acid sites which are<br />
responsible for the activity [10,11,14]. In this study,<br />
TS-1 loaded with titanium oxide has been synthesized<br />
and used as acidic catalysts <strong>in</strong> which the Ti atoms <strong>in</strong><br />
TS-1 acts as oxidative acid sites while titanium oxide<br />
deposited on the surface <strong>of</strong> TS-1 acts as Lewis acid<br />
sites. <strong>The</strong> effect <strong>of</strong> calc<strong>in</strong>ations temperature <strong>of</strong><br />
titanium oxide on the the structure and properties <strong>of</strong><br />
the catalyst was <strong>in</strong>vestigated.<br />
Materials and Methods<br />
Preparation <strong>of</strong> sample<br />
TS-1 conta<strong>in</strong><strong>in</strong>g 1% mol <strong>of</strong> titanium was prepared<br />
accord<strong>in</strong>g to a procedure describe earlier us<strong>in</strong>g<br />
tetraethyl ortosilicates (Merck,98%), tetraethyl<br />
ortotitanat (Merck 98%, TEOT) <strong>in</strong> 2-propanol,<br />
tetrapropylammonium hydroxide (Merck 20%<br />
TPAOH <strong>in</strong> water) and distilled water. <strong>The</strong> gel was<br />
charged <strong>in</strong>to a 150 mL autoclave and heated at 175 o C<br />
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under static condition. <strong>The</strong> material was recovered<br />
after 4 days by centrifugation and washed with excess<br />
distilled water. A white powder was obta<strong>in</strong>ed after<br />
dry<strong>in</strong>g <strong>in</strong> air at 100 o C overnight. <strong>The</strong> solid material<br />
was then calc<strong>in</strong>ed <strong>in</strong> air at 550 o C for 4 h.<br />
Sample TS-1 loaded with titanium oxide<br />
(TiO2/TS-1) was prepared by the impregnation<br />
method us<strong>in</strong>g tetraethyl ortotitanat TEOT precusor.<br />
TS-1 calc<strong>in</strong>ed was dried <strong>in</strong> oven at 110 o C overnight<br />
for 24 h. After that, the necessary amount <strong>of</strong> titanium<br />
oxide was dissolved <strong>in</strong> 2-propanol (Merck 98%) to<br />
obta<strong>in</strong> the desired metal loaidng and the required<br />
quantity <strong>of</strong> pre-dried <strong>of</strong> TS-1 was immediately added<br />
to the clear solution with stirr<strong>in</strong>g. <strong>The</strong> mixture was<br />
stirred at room temperature for 3 h. <strong>The</strong> solid was<br />
recovered by evaporat<strong>in</strong>g the 2-propanol at 80 o C.<br />
<strong>The</strong> acid hydrolysis was performed by addtion <strong>of</strong> 20<br />
mL solution <strong>of</strong> 0,5 M HNO3 <strong>in</strong> disttiled water and<br />
aged overnight, followed by heat<strong>in</strong>g at 120 o C until<br />
dryness. <strong>The</strong> solid was then washed with distilled<br />
water for three times and f<strong>in</strong>ally dried at 110 o C for 24<br />
h. <strong>The</strong> white solid was calc<strong>in</strong>ed at 400, 500, 600, and<br />
700 o C for 4 h.<br />
Titanium oxide was prepared by hydolysis <strong>of</strong><br />
tetraethyl ortotitanat (TEOT) at room temperature.<br />
<strong>The</strong> white solid was revcovered by filtration, wash<strong>in</strong>g<br />
with water and dry<strong>in</strong>g at 100oC overnight. F<strong>in</strong>ally,<br />
the solid was calc<strong>in</strong>ed at 550oC for 4h.<br />
Characterizations<br />
All sample were characterized by powder X-ray<br />
diffraction(XRD) for crystall<strong>in</strong>ity and phase content<br />
<strong>of</strong> the solid material, us<strong>in</strong>g Bruker Advance D8<br />
difractometer with Cu K Cu Kα (λ = 1.5405 Å) as the<br />
diffracted monochromatic beam at 40 kV and 30<br />
mA,. <strong>The</strong> patern was scanned <strong>in</strong> the 2θ ranges<br />
between 5–50 o at a step 0,02 o and step time 1s.<br />
Infrared (IR) spectra <strong>of</strong> the samples were collected on<br />
Shimadzu Fourier Transform Infrared (FTIR)n<br />
spectrometer with a spectral resolution <strong>of</strong> 2 cm −1 ,<br />
scan 10s, at temperature 20 o C with KBr wafer<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
methode. Infrared spectra <strong>of</strong> the samples were<br />
recorded at room temperature <strong>in</strong> the hydroxyl region<br />
<strong>of</strong> 1400-400 cm −1 .<br />
Hydrophobycity <strong>of</strong> catalyst was also analisized by<br />
us<strong>in</strong>g water adsorption technique. In a typical<br />
experiment, the catalysts were dried <strong>in</strong> an oven at<br />
110 o C for 24 h to remove all the physically adsorbed<br />
water. After dehydration, the sample was exposed to<br />
water vapor at room temperature, folllowed by the<br />
determ<strong>in</strong>ation <strong>of</strong> the percentage <strong>of</strong> adsorbed water as<br />
function <strong>of</strong> time.<br />
Results and Discussion<br />
X-ray diffraction<br />
Fig. 1 shows the XRD pattern <strong>of</strong> XTiO 2/TS-1 samples. <strong>The</strong><br />
samples are noted as XTiO 2/TS-1 where X denoted the<br />
calc<strong>in</strong>ation temperature. <strong>The</strong> diffraction pattern for the<br />
samples with 400, 500, 600 and 700 o C <strong>of</strong> calc<strong>in</strong>ation<br />
temperature show similar pattern to that <strong>of</strong> the parent TS-1<br />
as <strong>in</strong>dicated by the diffraction peaks at 2θ = 7,92º; 7,94º;<br />
8,80º; 23,06º; 23,08º; 23,10º; 23,24º; 23,26º; dan 23,28º.<br />
<strong>The</strong> presence<strong>of</strong> all the typical XRD peaks for TS-1<br />
<strong>in</strong>dicates the framework structure has been reta<strong>in</strong>ed after<br />
calc<strong>in</strong>ation. Fig 1 shown that no diffraction l<strong>in</strong>es for<br />
anatase-rutil phases <strong>of</strong> titanium oxide are observed<br />
<strong>in</strong>dicat<strong>in</strong>g that TiO 2 is highly dispersed on the surface <strong>of</strong><br />
TS-1. It is found that the MFI structure <strong>of</strong> TS-1 was<br />
ma<strong>in</strong>ta<strong>in</strong>ed after the impregnation titanium oxide and<br />
calc<strong>in</strong>ation preparation. However, the XRD peak <strong>in</strong>tensities<br />
<strong>of</strong> TS-1 decreased when calc<strong>in</strong>ation temperature was<br />
<strong>in</strong>creased. This might be due to the decreased <strong>in</strong> the<br />
precentage amount <strong>of</strong> TS-1 <strong>in</strong> the samples as calc<strong>in</strong>ation<br />
temperature <strong>of</strong> TiO 2 <strong>in</strong>creased<br />
Table can be illustrated us<strong>in</strong>g double (Table 1) or<br />
s<strong>in</strong>gle (Table 2) column, if necessary. Table started by<br />
table title (10 pts) that set above the table. Table is set<br />
centered alignment, and table limit must not exceed<br />
marg<strong>in</strong> <strong>of</strong> the page. If the title <strong>of</strong> the table more than<br />
one row, the second row should be formatted us<strong>in</strong>g<br />
hang<strong>in</strong>g <strong>in</strong>dent follow<strong>in</strong>g the above limit.<br />
Table. 1 <strong>The</strong> phase dan peak <strong>in</strong>tensities <strong>of</strong> samples from XRD<br />
Samples Intensities at 2Ө = 23,06<br />
Cps<br />
TS-1<br />
400 TiO2/TS-1<br />
500 TiO2/TS-1<br />
600 TiO2/TS-1<br />
700 TiO2/TS-1<br />
TiO2<br />
2696<br />
2652<br />
2635<br />
2619<br />
2604<br />
0<br />
<strong>The</strong> XRD pattern <strong>of</strong> TiO2 samples <strong>in</strong>dicated that<br />
structure <strong>of</strong> TiO2 was rutile. <strong>The</strong>re is no diffraction<br />
l<strong>in</strong>e assigned for crystall<strong>in</strong>e phase <strong>of</strong> titanium<br />
oxide present. This <strong>in</strong>dicated that niobium oxide<br />
was well dispersed on the TS-1. In addition, the<br />
Phase Intensities at 2Ө = 27,52<br />
( rutile phase)<br />
MFI<br />
MFI<br />
MFI<br />
MFI<br />
MFI<br />
Rutil<br />
Cps<br />
180<br />
413<br />
427<br />
438<br />
450<br />
1971<br />
peak <strong>in</strong>tensities <strong>of</strong> TS-1 decreased up to 0,4- 0,9 %<br />
(table 1) as <strong>in</strong>creased calc<strong>in</strong>ation temperature. It is<br />
suggested that titanium oxide is either located on<br />
the surface <strong>of</strong> TS-1 or crystall<strong>in</strong>e phase <strong>of</strong> TiO2<br />
cover<strong>in</strong>g the surface <strong>of</strong> TS-1 <strong>of</strong> TS-1.S<strong>in</strong>ce <strong>of</strong> Ti<br />
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site <strong>of</strong> TiO2 is larger than size pore entrance <strong>of</strong> TS-<br />
1, they should be attached to the external surface <strong>of</strong><br />
TS-1. <strong>The</strong> peak <strong>in</strong>tensities <strong>of</strong> rutil phase at 2θ =<br />
27,52º <strong>in</strong>creased up to 0,77-0,79% (table 2) as<br />
<strong>in</strong>creased calc<strong>in</strong>ation temperature. It is suggested<br />
that TiO2 which are dispersed <strong>in</strong> the surface <strong>of</strong> TS-1<br />
ma<strong>in</strong>ly due to partial transformation <strong>of</strong> anatase to<br />
rutile<br />
Fig 1. XRD pattern <strong>of</strong> the samples<br />
Tabel 1. Increased precentage peak <strong>in</strong>tensities <strong>of</strong><br />
samples TS-1 and TiO2/TS-1<br />
Sampel<br />
Persentase<br />
pengurangan<br />
<strong>in</strong>tensitas pola<br />
difraksi TS-1<br />
(%)<br />
Persentase<br />
pengurangan<br />
<strong>in</strong>tensitas pola<br />
difraksi fase<br />
rutil<br />
(%)<br />
TS-1<br />
-<br />
0,036<br />
400 TiO2/TS-1 0,458<br />
0,771<br />
500 TiO2/TS-1 0,635<br />
0,777<br />
600 TiO2/TS-1 0,082<br />
0,783<br />
700 TiO2/TS-1 0,958<br />
0,791<br />
TiO2<br />
-<br />
-<br />
Infrared Spectroscopy<br />
2θ, degree<br />
<strong>The</strong> <strong>in</strong>frared <strong>of</strong> spectra zeolite lattice vibration<br />
between 1400 and 400 cm -1 are depicted <strong>in</strong> Fig 2.<br />
Accord<strong>in</strong>g to Flanigen, the absorpstion bands at<br />
around 1100, 800, dan 450 cm -1 are lattice modes<br />
associated with <strong>in</strong>ternal l<strong>in</strong>kage <strong>in</strong> SiO4 or AlO4<br />
tetrahedral and are sensitive to structural changes.<br />
<strong>The</strong> absorpition bands at around 1230 dan 547 cm -1<br />
are characteristic <strong>of</strong> the MFI type zeolite structure<br />
and are sensitive to structure changes. All samples<br />
showed a band at around 970 cm -1 . the vibrational<br />
modes at around this frequency may be the result <strong>of</strong><br />
several contribution, i.e. the asymmetric strech<strong>in</strong>g<br />
modes <strong>of</strong> Si-O-Ti l<strong>in</strong>kages, term<strong>in</strong>al Si-O strech<strong>in</strong>g<br />
<strong>of</strong> Si-O-H-(HO)Ti” defective sites” and tytanyl<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
(Ti=O) vibrations[16,17,18,19]. However, this<br />
band can be attributed to the titanium <strong>in</strong> the<br />
framework, s<strong>in</strong>ce silicate, a Ti free zeolite, did not<br />
shoe any band at aroud this frequency. In addition,<br />
impregnation and <strong>in</strong>creased temperature calc<strong>in</strong>ation<br />
titanium oxide gave rise to no band around 970 cm -<br />
1 . <strong>The</strong>refore, it is concluded that the TS-1 sample<br />
conta<strong>in</strong>s Si-O-Ti connections. <strong>The</strong>re is no band<br />
shift<strong>in</strong>g or additional band observed after<br />
impregnation <strong>of</strong> titanium oxide on TS-1. Ths<br />
f<strong>in</strong>d<strong>in</strong>g suggest that both the MFI structure and<br />
titanium framework were still ma<strong>in</strong>ta<strong>in</strong>ed after both<br />
<strong>of</strong> impregnation and calc<strong>in</strong>ation temperature<br />
preparation <strong>of</strong> titanium oxide.<br />
Fig 2. FTIR Spectra <strong>of</strong> the samples<br />
c<br />
a b d<br />
Fig 3. Hydrophobicity test<strong>in</strong>g before stirr<strong>in</strong>g: a. TS-<br />
1; b. 400 TiO2/TS-1; C, 500 TiO2/TS-1; D.<br />
600 TiO2/TS-1; E. 700 TiO2/TS-1, F.TiO2<br />
a b e<br />
c d f<br />
Fig 4. Hydrophobicity test<strong>in</strong>g before stirr<strong>in</strong>g: a.<br />
TS-1; b. 400 TiO2/TS-1; c, 500 TiO2/TS-1;<br />
d. 600 TiO2/TS-1; e. 700 TiO2/TS-1, f.TiO2<br />
Proceed<strong>in</strong>g Book 575<br />
e<br />
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January 24, 2009<br />
As shown <strong>in</strong> Fig 3 and , it was clearly observed<br />
that the amount <strong>of</strong> adsorbed water on 700 and 600<br />
TiO2/TS-1 was significantly lower than 400 and<br />
500TiO2/TS-. This might be <strong>in</strong>dicated that<br />
<strong>in</strong>creased calc<strong>in</strong>ations temperature ma<strong>in</strong>ly due to<br />
the transformation anatase-rutil phase. <strong>The</strong> highly<br />
rutil phase <strong>of</strong> sample at high calc<strong>in</strong>ations<br />
temperature might be due to the agglomeration<br />
titanium oxide (8) <strong>in</strong> the surface <strong>of</strong> TS-1.Fig 3 and<br />
4 a, show that TS-1 not well dispersed to aqueous<br />
water. It is <strong>in</strong>dicates that TS-1 have naturally<br />
hydrophobic behavior. Impregnation titanium oxide<br />
to the surface <strong>of</strong> TS-1 enhanced hidrophylicity<br />
behavior.<br />
Conclusion<br />
Acidid catalyst have been sussesfuly prepared<br />
by the dispersion <strong>of</strong> titaniumoxide on TS-1 at<br />
modified <strong>of</strong> calc<strong>in</strong>ation temperature <strong>in</strong>creased up to<br />
400 and 700 o C. <strong>The</strong> catalyst have oxidative site due<br />
to titanium located <strong>in</strong> the framework os silicates,<br />
while octahedral titanium conta<strong>in</strong><strong>in</strong>g hidrophilic<br />
site. <strong>The</strong> best <strong>in</strong>cres<strong>in</strong>g hidrophilic behavior at 500<br />
TiO2/TS-1 due to highly dispersion <strong>of</strong> titanium<br />
oxide <strong>in</strong> the surface <strong>of</strong> TS-1. Temperature<br />
Calc<strong>in</strong>ation at 600-700 o C due to decreas<strong>in</strong>g<br />
hydrophilic behavior ma<strong>in</strong>ly transformation phase<br />
<strong>of</strong> anatase-rutil.<br />
Acknowledgements<br />
We gratefully acknowledgement fund<strong>in</strong>g from<br />
Directoration General <strong>of</strong> Highler Education<br />
Indonesiaunder Hibah Paska grant No<br />
1108/12.7/PM/2008.<br />
References<br />
[1] Almeida, R.M., Noda, L.K., Goncalves, N.S.,<br />
Meneghetti, S.M.P, dan Meneghetti, M.R.,<br />
“Transesterification Reaction <strong>of</strong> Vegetable<br />
Oils, Us<strong>in</strong>g Superacid sulfated TiO2-Base<br />
Catalysts”, Applied Catalysis A : General ,<br />
Vol. 347, hal. 100–105.<br />
[2] Atoguchi, T., Yao, S. (2001), “Phenol<br />
Oxidation over Titanosilicalite-<br />
1:Experimental and DFT <strong>Study</strong> <strong>of</strong> Solvent”,<br />
Journal <strong>of</strong> Molecular Catalysis A: Chemical,<br />
Vol. 176, hal. 173-178.<br />
[3] Bhattacharyya, A.,Kawi, S.,dan Ray, M.B.<br />
(2004),”Photocatalytic Degradation <strong>of</strong><br />
Orange II by TiO 2 Catalysts supported on<br />
Adsorbents”, Catalysis Today, Vol. 98, hal.<br />
470-479.<br />
[4] Bonelli, B., Cozzol<strong>in</strong>o, M., Tesser, R., Serio,<br />
M.D., Piumetti, M., dan Garrone, E. (2007),<br />
“<strong>Study</strong> <strong>of</strong> <strong>The</strong> surface acidity <strong>of</strong> TiO2/SiO2<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
Catalyst by Means <strong>of</strong> FTIR Measurements <strong>of</strong><br />
CO and NH3 Adsorption”, Journal <strong>of</strong><br />
Catalysis, Vol. 246, hal 293-300.<br />
[5] Belessi. V., Lambropoulou, D., Konstant<strong>in</strong>ou,<br />
I., Katsoulidis, A., Pomonis, P., Petridis, D.,<br />
dan Albanis, T. (2007),” Stucture and<br />
Photocatalytic Performance <strong>of</strong> TiO2/Clay<br />
Nanocomposites for <strong>The</strong> Degradation <strong>of</strong><br />
Dimethachlor”, Applied Catalysis B :<br />
Enviromental, Vol. 73, hal. 292–299.<br />
[6] Chen, J., Eberle<strong>in</strong>, L., Langford, C.H. (2002),<br />
“Pathways <strong>of</strong> Phenol and Benzene<br />
Photooxidation Us<strong>in</strong>g TiO2 supported on A<br />
<strong>Zeolite</strong>”, Journal <strong>of</strong> Photochemistry and<br />
Photobiology, Vol. 148, hal 183 -189.<br />
[7] Chun, S.W., Jang, J.Y., Park, D.W., Woo, H.C.,<br />
dan Chung, J.S. (1998), “Selective Oxidation<br />
<strong>of</strong> H2S to Elemental Sulfur Over TiO2/SiO2<br />
Catalysts”, Applied Catalysis B :<br />
Environmental , Vol. 16, hal. 235–243.<br />
[8] Corma, A., dan Garcia, H. (2002), “ Lewis Acid<br />
as Catalysts <strong>in</strong> Oxidation Reaction: From<br />
Homogenous to Heterogenous System”,<br />
Chemical Review, Vol. 102, hal 3837-3892.<br />
[9] Contsant<strong>in</strong>e, M., Popa, J.M., dan Gubelmann.<br />
(1993), “Hydroxylation <strong>of</strong> Phenols/Phenol<br />
Ethers”, (US.Patents 5.254.746).<br />
[10] Drago, R. S., Dias, S. C., McGilvray, J. M.,<br />
dan Mateus, A. L. M. L. (1998), “Acidity<br />
and Hydrophobicity <strong>of</strong> TS-1”, Journal <strong>of</strong><br />
Physical Chemistry, Vol. 102, hal. 1508-<br />
1514.<br />
[11] Esposito, A., Taramasso, M. and Neri, C.<br />
(1983). “Hydroxylat<strong>in</strong>g Aromatic<br />
Hydrocarbons”. (US Patent No. 4,396,783).<br />
[12] Huang, D.G., Liao, S.J., Liu, J.M, Dang, Z.,<br />
dan Petrik, L. ( 2006), ” Preparation <strong>of</strong><br />
Visible- Light Responsive N-F-codoped<br />
TiO2 Photocatalyst by A Sol Gel<br />
Solvothermal Method”, Journal <strong>of</strong><br />
Photochemistry and Photobiology, Vol. 164,<br />
hal 242-266.<br />
[13] Indrayani, S. (2008), Aktivitas Katalitik<br />
MoO3/TS-1 pada Reaksi Hidroksilasi Fenol<br />
menggunakan H2O2 , Tesis M.Sc., Jurusan<br />
Kimia, FMIPA Institut Teknologi Sepuluh<br />
Nopember, Surabaya.<br />
[14] Kung. H. H. (1989), “Transition Metal Oxides:<br />
Surface Chemistry and Catalysis”, <strong>Study</strong><br />
Surface Science and Catalysis. 45.<br />
[15] Lamberti, C., Bordiga, S., Zecch<strong>in</strong>a, A.,<br />
Artioli, G., Marra, G. and Spano, G.,<br />
(2001), “Ti Location <strong>in</strong> the MFI Framework<br />
<strong>of</strong> Ti-Silicalite-1: A Neutron Powder<br />
Diffraction <strong>Study</strong>”. Journal <strong>of</strong> Am. Chem.<br />
Soc., Vol. 123, hal. 2204-2212.<br />
[16] Li, G., Wang, X., Guo, X., Liu, S., Zhao, Q.,<br />
Bao, X., and L<strong>in</strong>, L. (2000). “Titanium<br />
Species <strong>in</strong> Titanium Silicalite TS-1 Prepared<br />
Proceed<strong>in</strong>g Book 576
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January 24, 2009<br />
By Hydrothermal Method”, Materials<br />
chemistry and Physics, Vol. 71, hal 195-<br />
201.<br />
[17] Machado, N.R.C, dan Santana, S.V. (2005),<br />
“Influence <strong>of</strong> <strong>The</strong>rmal Treatment on <strong>The</strong><br />
stucture and Photocatalytic Activity <strong>of</strong> TiO2<br />
P25”, Catalysis Today, Vol 107-108, hal.<br />
595-698.<br />
[18] Nur, H., Prasetyoko, D., Ramli, Z., Endud, S.<br />
(2004), “Sulfation: A simple Method to<br />
enhance the Catalytic Activity <strong>of</strong> TS-1 <strong>in</strong><br />
Epoxidation <strong>of</strong> 1-octene with Aqueous<br />
Hydrogen Peroxide”, Catalysis<br />
Communications . Vol.5, hal. 725–728.<br />
[19] Nur, H., (2006), Heterogeneous<br />
Chemocatalysis: Catalysis by Chemical<br />
Design, Ibnu S<strong>in</strong>a Institute for Fundamental<br />
Science Studies Universiti Teknologi<br />
Malaysia, Johor Bahru.<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
Proceed<strong>in</strong>g Book 577
<strong>The</strong> First International Sem<strong>in</strong>ar on Science and Technology<br />
January 24, 2009<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
Improved Properties <strong>of</strong> SnTiO3 Th<strong>in</strong> Film Light Sensor<br />
Prepared by Sol-Gel Method<br />
Tulus Ikhsan Nasution 1,2* , Zaliman Sauli 1 , Hasnizah Aris 1 and Eddy Marlianto 2<br />
1 School <strong>of</strong> Microelectronic Eng<strong>in</strong>eer<strong>in</strong>g<br />
Universiti Malaysia Perlis, 02600 Kangar, Perlis, Malaysia<br />
2 Faculty <strong>of</strong> Mathematics and Natural Sciences<br />
Universitas Sumatera Utara, Medan 20155, Indonesia<br />
*e-mail ikhsan@unimap.edu.my<br />
Abstract<br />
Th<strong>in</strong> films based on SnTiO3 sens<strong>in</strong>g material have been successful to deposit on the silicon<br />
(Si) substrates. <strong>The</strong> films were annealed at 700 o C <strong>in</strong> air for 30 s. <strong>The</strong> surface roughness <strong>of</strong><br />
the films was observed by us<strong>in</strong>g an Atomic Force Microscopic (AFM). <strong>The</strong> current-voltage<br />
characteristics were measured at the relative low positive voltages under the condition<br />
without and with light exposure. It was found that the electrical currents <strong>of</strong> SnTiO3<br />
composite are higher compared with those <strong>of</strong> s<strong>in</strong>gle phase SnO2 both without and with light<br />
exposure. <strong>The</strong> improved properties <strong>of</strong> SnTiO3 composites are related to its smoother<br />
surface and smaller gra<strong>in</strong> size than SnO2.<br />
Keywords: Th<strong>in</strong> film, Sensitivity, Sol-gel, T<strong>in</strong> dioxide, T<strong>in</strong> Titanate<br />
Introduction<br />
T<strong>in</strong> dioxide (SnO2) has been well known as a high<br />
performance n-type semiconductor with a large band<br />
gap. Thus, light will be easy to penetrate <strong>in</strong>to this<br />
material and generate the free carriers [1-2]. An<br />
improvement <strong>of</strong> the electrical properties can be done<br />
if the semiconductor oxide adsorbs the light because<br />
the adsorption can result <strong>in</strong> a photoexcitation,<br />
affect<strong>in</strong>g the charge transport across the gra<strong>in</strong><br />
boundaries [3]. This provides an advantage which<br />
enables the sensors based on semiconductor oxide<br />
have high performance. However, a strong demand <strong>of</strong><br />
the commercial market for reliable and low cost<br />
sensors leads to the need <strong>of</strong> cont<strong>in</strong>uously develop<strong>in</strong>g<br />
new sens<strong>in</strong>g materials with the improved properties.<br />
<strong>The</strong> sensor fabrication <strong>in</strong> small size is also to be<br />
important work because it makes easy to <strong>in</strong>tegrate it<br />
<strong>in</strong>to an electrical circuit [4].<br />
Many methods can be utilized to produce a variety<br />
<strong>of</strong> new sens<strong>in</strong>g materials, especially <strong>in</strong>clud<strong>in</strong>g<br />
chemical processes. In this work, sol-gel method is<br />
considered to be the most suitable method to prepare<br />
SnTiO3 composite as a sens<strong>in</strong>g material due to this<br />
method <strong>of</strong>fers some significant advantages such as<br />
purity and homogeneity that can be obta<strong>in</strong>ed by the<br />
distillation. <strong>The</strong> low capital cost <strong>of</strong> the equipment and<br />
simplicity make it an excellent technique for<br />
formulat<strong>in</strong>g new compositions [5-6].<br />
<strong>The</strong> electrical conductance <strong>of</strong> SnTiO3 th<strong>in</strong> film<br />
sensors are exam<strong>in</strong>ed under light exposure (photo<br />
current) and no light exposure (dark current) to<br />
<strong>in</strong>vestigate the effect <strong>of</strong> light <strong>in</strong>tensity to the<br />
photocurrent. <strong>The</strong> characterizations <strong>of</strong> its structural<br />
and electrical properties are also carried out to expla<strong>in</strong><br />
an important role <strong>of</strong> gra<strong>in</strong> size distribution, gra<strong>in</strong><br />
boundaries and surface state <strong>in</strong> <strong>in</strong>creas<strong>in</strong>g the<br />
sensitivity <strong>of</strong> SnO2-TiO3 th<strong>in</strong> film sensors.<br />
Materials and Methods<br />
T<strong>in</strong> acetate [Sn(CH3COO)2] and titanium<br />
isopropoxide [Ti(OC3H7)4] were used as start<strong>in</strong>g<br />
materials to prepare the precursor solution <strong>of</strong> SnTiO3.<br />
<strong>The</strong> 2-methoxyethanol (2-MOE) was used as a<br />
solvent. Titanium isopropoxide was dissolved <strong>in</strong> the<br />
2-MOE, then t<strong>in</strong> acetate was added <strong>in</strong>to the titanium<br />
solution. After agitat<strong>in</strong>g the mixture <strong>of</strong> t<strong>in</strong>-titanium<br />
(Sn-Ti) <strong>in</strong> 2-MOE for 4 hours, Sn-Ti complex<br />
solution was obta<strong>in</strong>ed.<br />
<strong>The</strong> precursor solution was then sp<strong>in</strong>-coated onto<br />
Al/SiO2/Si substrate at 3000 rpm for 30 s. <strong>The</strong> sp<strong>in</strong>coated<br />
wet films were pre-baked at 90 o C for 30<br />
m<strong>in</strong>utes over a hot-plate to remove the organic<br />
contam<strong>in</strong>ations. This procedure was performed<br />
several times to obta<strong>in</strong> the appropriate thickness. <strong>The</strong><br />
films were f<strong>in</strong>al-annealed at 700 o C for 15 s <strong>in</strong> a rapid<br />
thermal anneal<strong>in</strong>g processor. <strong>The</strong> surface roughness<br />
and gra<strong>in</strong> size <strong>of</strong> SnO2 and SnTiO3 th<strong>in</strong> films were<br />
characterized by atomic force microscope (AFM).<br />
<strong>The</strong> current-voltage (I-V) measurements <strong>of</strong> the SnO2<br />
and SnTiO3 th<strong>in</strong> films were carried out by us<strong>in</strong>g<br />
semiconductor parametric analyzer (SPA) from 0 to 1<br />
V <strong>in</strong> air.<br />
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Results and Discussion<br />
Figure 1 (a) and (b) show the three-dimensional<br />
micrographs <strong>of</strong> SnO2 and SnTiO3 th<strong>in</strong> films deposited<br />
by us<strong>in</strong>g a sol-gel deposition technique. <strong>The</strong> AFM<br />
observation was carried out <strong>in</strong> contact mode with a<br />
scan area <strong>of</strong> 5000 nm x 5000 nm and a scan speed <strong>of</strong><br />
2 Hz. <strong>The</strong> micrographs <strong>in</strong>dicate that SnTiO3 has the<br />
smoother surface roughness compared with SnO2.<br />
Fig. 1 Three-dimensional AFM images <strong>of</strong> the<br />
surface <strong>of</strong> the BST th<strong>in</strong> film pre-s<strong>in</strong>tered at<br />
(a) 400 o C and (b) 600 o C.<br />
This is evident from the three-dimensional<br />
micrographs, where the z-scale range <strong>in</strong>creased from<br />
100 nm (Fig. 1 (a) to 150 nm (Fig. 1 (b). This is also<br />
confirmed with the gra<strong>in</strong> size <strong>of</strong> SnO2 decreased from<br />
about 220 nm to about 95 nm. Beside that, no<br />
microcracks are observed on the surface <strong>of</strong> both films<br />
that enables to get the reliable data when the electrical<br />
measurement is repeated.<br />
<strong>The</strong> addition <strong>of</strong> Ti elements <strong>in</strong>to SnO2 caused the<br />
gra<strong>in</strong> growth rate to be slower dur<strong>in</strong>g anneal<strong>in</strong>g<br />
process. <strong>The</strong> degree <strong>of</strong> roughness is represented by<br />
mean roughness which is the mean value relative to<br />
the centre l<strong>in</strong>e or plane. <strong>The</strong> surface area difference is<br />
def<strong>in</strong>ed as a percentage <strong>in</strong>crease <strong>in</strong> a comparison <strong>of</strong><br />
the 3-dimensional surface area produced by<br />
project<strong>in</strong>g the surface onto the threshold plane. <strong>The</strong><br />
mean gra<strong>in</strong> size is statistically calculated from the<br />
total number <strong>of</strong> gra<strong>in</strong>s [7].<br />
Figure 2 shows the behavior <strong>of</strong> electrical current<br />
<strong>of</strong> SnO2 and SnTiO3 th<strong>in</strong> films without and with light<br />
exposure as a function <strong>of</strong> vary<strong>in</strong>g voltages. <strong>The</strong><br />
currents <strong>in</strong>creased steeply with <strong>in</strong>creas<strong>in</strong>g the applied<br />
voltage up to around 0.55 V and above 0.55 V, the<br />
current <strong>in</strong>creased modestly with the <strong>in</strong>crease <strong>of</strong> the<br />
applied voltage. <strong>The</strong> current difference between SnO2<br />
and SnTiO3 is less without light illum<strong>in</strong>ation.<br />
Whereas under light illum<strong>in</strong>ation, SnTiO3 shows<br />
higher current values compared with SnO2. This<br />
result <strong>in</strong>dicates the Ti elements <strong>in</strong> SnO2 is surely<br />
act<strong>in</strong>g as a light absorb<strong>in</strong>g elements. <strong>The</strong><br />
measurements were done under the constant energy<br />
irradiation. It was also found that both SnO2 and<br />
SnTiO3 have fast response to the light that falls on<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
their surface. <strong>The</strong> similar results are obta<strong>in</strong>ed for<br />
repeated measurement.<br />
Current (mA)<br />
800<br />
700<br />
600<br />
500<br />
400<br />
300<br />
200<br />
100<br />
SnO 2 (Without Light)<br />
SnO 2 (With Light)<br />
SnTiO 3 (Without Light)<br />
SnTiO 3 (With Light)<br />
0<br />
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1<br />
Voltage (V)<br />
Fig. 2: I-V curves for SnO2 and SnTiO3 th<strong>in</strong> films.<br />
Fig 3. <strong>The</strong> sensitivity <strong>of</strong> SnO2 and SnTiO3 to the light<br />
Compar<strong>in</strong>g the current values under light<br />
illum<strong>in</strong>ation and without light illum<strong>in</strong>ation provides<br />
the sensitivity values as depicted <strong>in</strong> Figure 3. It was<br />
found that the sensitivity <strong>of</strong> SnTiO3 is higher than that<br />
<strong>of</strong> SnO2. It is believed that the <strong>in</strong>crease <strong>in</strong> sensitivity<br />
<strong>of</strong> SnO2 with the <strong>in</strong>corporation <strong>of</strong> Ti element is<br />
affected by the reduction <strong>of</strong> particle size which causes<br />
SnTiO3 is to be more porous compared with SnO2.<br />
<strong>The</strong>refore, the higher sensitivity <strong>of</strong> SnTiO3 is ascribed<br />
to an enhancement <strong>of</strong> light adsorption by the light<br />
conf<strong>in</strong>ement with<strong>in</strong> porous SnTiO3 layer as<br />
previously reported for porous TiO2 th<strong>in</strong> film [8]. <strong>The</strong><br />
Ti activities <strong>in</strong> light adsorption or the change <strong>in</strong><br />
Fermi-level can be considered to be responsible for<br />
the <strong>in</strong>creased sensitivity. However, the further<br />
<strong>in</strong>vestigations are needed to prove the correctness <strong>of</strong><br />
these prelim<strong>in</strong>ary expectations.<br />
Conclusion<br />
<strong>The</strong> conclusion <strong>of</strong> this study can be summarized as<br />
the follow<strong>in</strong>g:<br />
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January 24, 2009<br />
<strong>The</strong> addition <strong>of</strong> Ti element <strong>in</strong>to SnO2 structure has an<br />
effect to <strong>in</strong>crease it’s electrical current and <strong>in</strong> turns,<br />
causes the sensitivity <strong>of</strong> SnTiO3 is higher compared<br />
with that <strong>of</strong> SnO2. It is believed that the smoother<br />
surface roughness <strong>of</strong> SnTiO3 than SnO2 plays an<br />
important role for the improved electrical properties.<br />
Add<strong>in</strong>g the thickness <strong>of</strong> the films is believed can<br />
<strong>in</strong>crease the sensitivity to be much higher from the<br />
present results.<br />
Acknowledgements<br />
<strong>The</strong> f<strong>in</strong>ancial support from Universiti Malaysia Perlis<br />
(UniMAP), Universitas Sumatera Utara (USU) and<br />
FRGS 9003-00184 is greatfully acknowledged.<br />
References<br />
[1] Nishikawa, S., Hashimoto, H., Chikamoto, M.,<br />
Horikoshi, K., Aoki, M., Arima, K., Uchikosi,<br />
J. and Morita, M. 2006. Photo current through<br />
SnO2/SiC/p-Si(100) structures, Th<strong>in</strong> Solid<br />
Films, 508, 385-388.<br />
[2] Wu, C. L., Chou, J. C., Chung, W. Y., Sun, T.<br />
P. and Hsiung, S. K. 2000. <strong>Study</strong> on<br />
SnO2/Al/SiO2/Si ISFET with a metal light<br />
shield, Materials Chemistry and Physics, 63,<br />
153-156.<br />
[3] Com<strong>in</strong>i, E, Faglia, G. and Sberveglieri. 2001.<br />
UV light activation <strong>of</strong> t<strong>in</strong> oxide th<strong>in</strong> films for<br />
NO2 sens<strong>in</strong>g at low temperatures, Sensors and<br />
Actuators B, 78, 73-77.<br />
[4] Nasution, T. I, Sauli, Z. and Omar, R. 2006.<br />
Electrical and sens<strong>in</strong>g properties <strong>of</strong><br />
SnO2(4mol%ZnO)/CuO(4mol%ZnO) heterocontact<br />
gas sensor hav<strong>in</strong>g the sensitivity to CO<br />
gas, Proceed<strong>in</strong>gs <strong>of</strong> the International<br />
Conference on Mathematics and Natural<br />
Sciences (ICMNS), Bandung, Indonesia, ISBN<br />
979-3507-91-8.<br />
[5] Nasution, T. I., Zaliman, Johari, Azhar, Z.,<br />
Tak<strong>in</strong>g, S. Hikam, M. N. and Idris, M. A. 2007.<br />
Effect <strong>of</strong> Pre-S<strong>in</strong>ter<strong>in</strong>g Temperature on the<br />
Electrical Properties <strong>of</strong> Ba0.5Sr0.5TiO3 Th<strong>in</strong><br />
Films Derived from a Solution Deposition,<br />
Proceed<strong>in</strong>gs <strong>of</strong> IEEE Regional Symposium on<br />
Microelectronics, ISBN 9-789839-933543.<br />
[6] Nasution, T. I., Zaliman, Johari, Azhar, Z.,<br />
Tak<strong>in</strong>g, S. Hikam, M. N. and Idris, M. A. 2007.<br />
<strong>The</strong> Electrical Properties <strong>of</strong> Ba0.5Sr0.5TiO3 Th<strong>in</strong><br />
Films to the Different Temperatures,<br />
Proceed<strong>in</strong>gs <strong>of</strong> IEEE Regional Symposium on<br />
Microelectronics, ISBN 9-789839-933543.<br />
[7] Cantal<strong>in</strong>i, C., Pel<strong>in</strong>o, M., Sun, H. T., Faccio, M.,<br />
Santucci, S., Lozzi, L. and Passacantando, M.<br />
1996. Cross sensitivity and stability <strong>of</strong> NO2<br />
sensors from WO3 th<strong>in</strong> film, Sensors and<br />
Actuators B, 35-36, 112-118.<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
[8] Okuya, M., Shiozaki, K., Horikawa, N.,<br />
Kosugi, T., Kumara, G. R. A., Madarasz, J.,<br />
Kaneko, S. and Pokol, G. 2004. Porous TiO2<br />
th<strong>in</strong> films prepared by spray pyrolysis<br />
deposition (SPD) technique and their<br />
application to UV sensors, Solid State Ionics,<br />
172, 527-531.<br />
Proceed<strong>in</strong>g Book 580
<strong>The</strong> First International Sem<strong>in</strong>ar on Science and Technology<br />
January 24, 2009<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
Application <strong>of</strong> Chit<strong>in</strong> and Chitosan Isolated from Waste <strong>of</strong><br />
Java Sea White Shrimp (penaeus merguensis) as Adsorbent<br />
Khabibi, Rum Hastuti, Sri Syufa’ati<br />
Department <strong>of</strong> Chemistry, University <strong>of</strong> Diponegoro<br />
Abstract<br />
Research <strong>of</strong> adsorption rhodam<strong>in</strong>e by chit<strong>in</strong> and chitosan that isolated from waste <strong>of</strong> java sea white<br />
shrimp (penaeus merguensis) have been done. <strong>The</strong> purpose <strong>of</strong> this research is to isolate chit<strong>in</strong> from<br />
the waste <strong>of</strong> white shrimp sk<strong>in</strong>, transformation <strong>of</strong> chit<strong>in</strong> to chitosan, and that application as adsorbent<br />
rhodam<strong>in</strong>e <strong>in</strong> pH, time <strong>of</strong> optimum contact and determ<strong>in</strong>e the maximum adsorption capacity <strong>of</strong><br />
rhodam<strong>in</strong>e. Chit<strong>in</strong> was isolated from waste <strong>of</strong> java sea white shrimp (penaeus merguensis) through<br />
deprote<strong>in</strong>ation, dem<strong>in</strong>eralization, and depigmentation processes. transformation <strong>of</strong> chit<strong>in</strong> to chitosan<br />
through deacetylation processes. Chit<strong>in</strong> and chitosan usage as adsorbent <strong>of</strong> rhodam<strong>in</strong>e is conducted<br />
<strong>in</strong> pH variation <strong>of</strong> 2, 3, 4, 5, 6, 7, 8, and 10, contact time <strong>of</strong> 15, 30, 45, and 60 m<strong>in</strong>utes. Concentrate <strong>of</strong><br />
60, 120, 180, 240, and 300 ppm with volume <strong>of</strong> sample 20 ml, stir<strong>in</strong>g speed 150 rpm and the amount<br />
<strong>of</strong> chit<strong>in</strong>/chitosan 1 g. Analysis <strong>of</strong> chit<strong>in</strong> and chitosan us<strong>in</strong>g FTIR spectrometer to determ<strong>in</strong>e the<br />
groups that found on chit<strong>in</strong> and chitosan. <strong>The</strong> quantity residu <strong>of</strong> rhodam<strong>in</strong>e which not adsorb by chit<strong>in</strong><br />
and chitosan were analyzed usely UV-Vis, while to determ<strong>in</strong>e the maximum adsorption capacity<br />
us<strong>in</strong>g the Langmuir isotherm equalization.<br />
<strong>The</strong> result <strong>of</strong> extraction is ga<strong>in</strong>ed white-colour chit<strong>in</strong> and white-grayish chitosan obta<strong>in</strong>ed conta<strong>in</strong>ed<br />
70.48%. <strong>The</strong> optimum adsorption pH <strong>of</strong> chit<strong>in</strong> <strong>in</strong>to rhodam<strong>in</strong>e occurs <strong>in</strong> pH <strong>of</strong> 5 and the optimum<br />
adsorption <strong>of</strong> chitosan <strong>in</strong>to rhodam<strong>in</strong>e <strong>in</strong> pH 3. Time <strong>of</strong> adsorption optimum contact <strong>of</strong> rhodam<strong>in</strong>e by<br />
chit<strong>in</strong> and chitosan occurs <strong>in</strong> 30 m<strong>in</strong>utes. <strong>The</strong> maximum adsorption capacity chit<strong>in</strong> <strong>of</strong> rhodam<strong>in</strong>e 5.69<br />
mg/g and the maximum adsorption capacity chitosan <strong>of</strong> rhodam<strong>in</strong>e 6.55 mg/g. it is concluded that<br />
chitosan more effective as adsorbent rhodam<strong>in</strong>e than chit<strong>in</strong>.<br />
Keywords: chit<strong>in</strong>, chitosan, adsorption, rhodam<strong>in</strong>e, white shrimp<br />
Introduction<br />
Rhodam<strong>in</strong>e is one <strong>of</strong> dye that used widely for<br />
papers, textile and snacks <strong>in</strong>dustries (Ism<strong>in</strong><strong>in</strong>gsih,<br />
1973). Rhodam<strong>in</strong>e is resistant to sunlight effect and<br />
difficult to be degraded biologically because its<br />
relative stable aromatic structure. Rhodam<strong>in</strong>e waste<br />
is very dangerous for human life because it can be<br />
accumulated <strong>in</strong> a body and cause liver cancer.<br />
(C2H5)2N<br />
O<br />
C<br />
COOH<br />
N + (C2H5)2Cl -<br />
Figure 1. Structure <strong>of</strong> Rhodam<strong>in</strong>e<br />
Besides waste from dye<strong>in</strong>g at textile, there<br />
is another source <strong>of</strong> Rhodam<strong>in</strong>e waste that is from<br />
shrimp process<strong>in</strong>g as an export commodity <strong>in</strong> a<br />
form <strong>of</strong> shrimp without head and shell so that the<br />
shrimp waste are head and shell <strong>of</strong> shrimp as<br />
additional product.<br />
North Java Ocean as a shrimp producer<br />
produces more than 50 thousand tons a year.<br />
Shrimp produc<strong>in</strong>g produces shrimp waste that is<br />
30-40 % from the whole shrimp weight (Moeljanto,<br />
1984). S<strong>in</strong>ce now, shrimp shell waste uses for<br />
fodder or food <strong>in</strong>dustry such as shrimp chips<br />
(Benjakul and Shophanodora, 1993).<br />
Shrimp shells conta<strong>in</strong>s chit<strong>in</strong> (Muzzarelli 1985)<br />
function<strong>in</strong>g as adsorption <strong>of</strong> organic compound and<br />
pigment substance because chit<strong>in</strong> has amide bunch<br />
(-NHCO) and Hydroxyl bunch (-OH) as active site.<br />
Chit<strong>in</strong> can be isolated from shrimp shell through<br />
de-prote<strong>in</strong>asi, dem<strong>in</strong>eralization, and depigmentation<br />
processes.<br />
H<br />
CH2OH<br />
H<br />
OH<br />
H<br />
O<br />
H<br />
NHCOCH3<br />
H<br />
O<br />
H<br />
CH2OH<br />
H<br />
OH<br />
H<br />
O<br />
H<br />
NHCOCH3<br />
kii<br />
Figure 2. Structure <strong>of</strong> Chit<strong>in</strong><br />
Chit<strong>in</strong> can be changed <strong>in</strong>to chitosan<br />
through deasitilasi, that causes N-acetyl released so<br />
that it changes an unit <strong>of</strong> N-acetyl glucosam<strong>in</strong>e <strong>in</strong>to<br />
an unit <strong>of</strong> glucosam<strong>in</strong>e (Robert, 1992) because<br />
chitosan has am<strong>in</strong>e bunch (-NH2) and Hydroxyl (-<br />
OH) as active bunch so that chitosan can be used as<br />
adsorbent either organic or <strong>in</strong>organic compounds.<br />
Proceed<strong>in</strong>g Book 581<br />
H<br />
CH 2OH<br />
H<br />
OH<br />
H<br />
O<br />
H<br />
NH 2<br />
H<br />
O<br />
H<br />
CH 2OH<br />
H<br />
OH<br />
H<br />
O<br />
H<br />
NH 2<br />
H<br />
O<br />
H<br />
O<br />
n<br />
n
<strong>The</strong> First International Sem<strong>in</strong>ar on Science and Technology<br />
January 24, 2009<br />
Figure 3. Structure <strong>of</strong> Chitosan<br />
Filipkowska (2007) had used chit<strong>in</strong> as<br />
adsorbent <strong>of</strong> black 8 and black 5 colors with<br />
optimum adsorption at pH 6 while Chiou et al<br />
(2003) argued that chitosan can be used as pigment<br />
substance <strong>of</strong> AAVN (Acid Alizar<strong>in</strong> Violet N) and<br />
RB4 (Reactive Blue 4) at pH 3. Setyadi (2005) was<br />
made chitosan as pigment adsorbent <strong>of</strong> <strong>in</strong>digo<br />
carm<strong>in</strong>e through chromatography method with<br />
maximum adsorption chitosan toward <strong>in</strong>digo<br />
carm<strong>in</strong>e at pH 4. Indigo carm<strong>in</strong>e, AAVN, RB4 and<br />
Rhodam<strong>in</strong>e have similar structure. Those are<br />
aromatic compounds. Thus, Rhodam<strong>in</strong>e is expected<br />
capable to be adsorbed by chit<strong>in</strong> and chitosan. <strong>The</strong><br />
objective <strong>of</strong> this research is to isolate chit<strong>in</strong> from<br />
white shrimp shell waste, from Java sea, and<br />
transform to be chitosan, and determ<strong>in</strong>e its effect as<br />
rhodam<strong>in</strong>e adsorbent.<br />
Materials and Methods<br />
Materials<br />
Dry white shrimp (penaeus merguensis) shell<br />
powder from java sea, NaOH (p.a merck), HCl (p.a<br />
merck), H2O2 (p.a merck), citric acid (p.a merck),<br />
Na2HPO4 (p.a merck).<br />
Chit<strong>in</strong> and Chitosan Extraction<br />
Two hundred grams <strong>of</strong> dry shrimp shell powder is<br />
added by a liter <strong>of</strong> 3,5 % NaOH, then heat at 65°C<br />
for 2 hours along mix<strong>in</strong>g. <strong>The</strong>n, the mixture is<br />
filtered and washed by aquades. Residue is added to<br />
HCL 1 N heated at temperature <strong>of</strong> 65°C for 2 hours.<br />
Residue is put at 250 ml <strong>of</strong> 3% H2O2 for 24 hours<br />
by 2 times <strong>of</strong> soak<strong>in</strong>g. <strong>The</strong> mixture is filtered and<br />
residue is washed by aquadest then dried by oven at<br />
80°C for 8 hours <strong>of</strong> chit<strong>in</strong> purify<strong>in</strong>g process.<br />
Chit<strong>in</strong> transformation to become chitosan:<br />
Residue is added by 500 ml <strong>of</strong> 50 % NaOH solution<br />
then heated at 100°C for 2 hours with mix<strong>in</strong>g. <strong>The</strong><br />
mixture is filtered and residue is washed by<br />
aquadest until neutral. <strong>The</strong> residue is dried at 80°C<br />
for 8 hours to get chitosan powder. Characteriz<strong>in</strong>g<br />
<strong>of</strong> result (Chit<strong>in</strong> and chitosan) is analyzed us<strong>in</strong>g<br />
spectrophotometer FTIR.<br />
Rhodam<strong>in</strong>e adsorption by chit<strong>in</strong> and chitosan<br />
with various pH<br />
A gram <strong>of</strong> chit<strong>in</strong>/ chitosan powder put <strong>in</strong><br />
Erlenmeyer. <strong>The</strong>n, 20 ml solution <strong>of</strong> 660 ppm<br />
Rhodam<strong>in</strong>e sample with various pH i.e.<br />
2,3,4,5,6,7,8 and 10 is added <strong>in</strong>to it and shake it by<br />
bath shaker dur<strong>in</strong>g 30 m<strong>in</strong>utes, room temperature.<br />
<strong>The</strong> solution, the result <strong>of</strong> adsorption, is measured<br />
absorbency us<strong>in</strong>g spectrophotometer UV-vis at 570<br />
nm.<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
Rhodam<strong>in</strong>e adsorption by chit<strong>in</strong> and chitosan with<br />
various time-contacts<br />
Each <strong>of</strong> 4 Erlenmeyer is added with 20 ml <strong>of</strong> 60<br />
ppm Rhodam<strong>in</strong>e and a gram <strong>of</strong> Chit<strong>in</strong>/ Kitosan at<br />
optimum pH and then shakes with bath shaker for<br />
15, 30, 45 and 60 m<strong>in</strong>utes. <strong>The</strong> solution, the result<br />
<strong>of</strong> adsorption, is measured quantitatively us<strong>in</strong>g<br />
spectrophotometer UV-vis at 570 nm.<br />
Rhodam<strong>in</strong>e adsorption by chit<strong>in</strong> and chitosan with<br />
various concentration.<br />
Rhodam<strong>in</strong>e solution <strong>in</strong> different concentration: 60,<br />
120, 180, 240, and 330 ppm is added with a gram <strong>of</strong><br />
chit<strong>in</strong>/ chitosan then shake us<strong>in</strong>g bath shaker at<br />
optimum time and pH. <strong>The</strong> solution, the result <strong>of</strong><br />
adsorption, is measured quantitatively us<strong>in</strong>g<br />
spectrophotometer UV-vis at 570 nm.<br />
Results and Discussion<br />
Chit<strong>in</strong> and chitosan Extraction<br />
Chit<strong>in</strong> subtracts from shrimp shells by do<strong>in</strong>g chit<strong>in</strong><br />
extraction from shrimp shell powder through<br />
process <strong>of</strong> de-prote<strong>in</strong>asi, dem<strong>in</strong>eralization while to<br />
get chitosan can do by deasetilasi process. Deprote<strong>in</strong>asi<br />
process can cause the bunch <strong>of</strong> prote<strong>in</strong><br />
and chit<strong>in</strong> released. Dem<strong>in</strong>eralization is the process<br />
<strong>of</strong> the elim<strong>in</strong>ation toward m<strong>in</strong>eral <strong>of</strong> shrimp shells.<br />
M<strong>in</strong>eral <strong>of</strong> shrimp shells is CaCO3. Thus, us<strong>in</strong>g<br />
HCL, the m<strong>in</strong>eral <strong>of</strong> shrimp shells can be<br />
elim<strong>in</strong>ated because the form<strong>in</strong>g <strong>of</strong> CaCl2 that can be<br />
elim<strong>in</strong>ated. <strong>The</strong> equation <strong>of</strong> reaction is:<br />
2HCL + CaCO3 CaCl2 + H2CO3<br />
De-pigmentation process is a process to elim<strong>in</strong>ate<br />
pigment so that it becomes white residue. <strong>The</strong> depigmentation<br />
is a process us<strong>in</strong>g 3% <strong>of</strong> H2O2 that<br />
function<strong>in</strong>g as strong oxidant. <strong>The</strong> result <strong>of</strong><br />
extraction is ga<strong>in</strong>ed white-colour chit<strong>in</strong>. <strong>The</strong> f<strong>in</strong>al<br />
residue outcome is Chit<strong>in</strong> and analyzed us<strong>in</strong>g<br />
spectrosphometer FTIR, with result as <strong>in</strong> Figure 1.<br />
Figure 4. Spectra FTIR <strong>of</strong> chit<strong>in</strong><br />
Proceed<strong>in</strong>g Book 582
<strong>The</strong> First International Sem<strong>in</strong>ar on Science and Technology<br />
January 24, 2009<br />
Table 1 Wave number and prediction groups<br />
funtional <strong>in</strong> chit<strong>in</strong><br />
Wave Number (cm -<br />
Prediction funtional<br />
1<br />
)<br />
groups<br />
3443,74 Stretch<strong>in</strong>g N-H<br />
overlapp O-H<br />
2927,05 Stretch<strong>in</strong>g C-H<br />
alifatik<br />
1653,11<br />
Stretch<strong>in</strong>g C=O<br />
1559,87<br />
N-H sekunder<br />
1379,34 Stretch<strong>in</strong>g CH3<br />
1157,14 Stretch<strong>in</strong>g C-O eter<br />
1073,26 dan<br />
1029,62<br />
Stretch<strong>in</strong>g C-N<br />
Figure 5. Spectra FTIR <strong>of</strong> chitosan<br />
Table 2 Wave number and prediction groups<br />
funtional <strong>in</strong> chitosan<br />
Wave Number (cm -1 ) Prediction funtional<br />
groups<br />
3442,91 Stretch<strong>in</strong>g N-H overlapp<br />
2922,39<br />
1652,98<br />
1558,51<br />
O-H<br />
Stretch<strong>in</strong>g C-H alifatik<br />
Stretch<strong>in</strong>g C=O<br />
Stretch<strong>in</strong>g N-H<br />
1034,98 Stretch<strong>in</strong>g C-N<br />
Obta<strong>in</strong>ed Chit<strong>in</strong> is then deasetilated, is a<br />
process <strong>of</strong> reduc<strong>in</strong>g acetyl (-COCH3) groups<br />
substituted with hydrogen groups so that amide (-<br />
NHCOCH3) change to am<strong>in</strong>a (-NH2) group<br />
(Tokura,1995). Deasetilation degree is determ<strong>in</strong>ed<br />
by base l<strong>in</strong>e method and obta<strong>in</strong>ed 70,48%.<br />
<strong>The</strong> result <strong>of</strong> deasetilation is white-grayish chitosan<br />
Analysis outcome <strong>of</strong> chitosan Spectra FTIR (Figure<br />
2), show correspondence <strong>of</strong> some groups chitosan<br />
function accord<strong>in</strong>g to Sastrohamidjojo, 1991;<br />
Khopkar, 1990; and Fessenden, 1992. Chitosan<br />
function groups resulted <strong>in</strong> Spectra FTIR seen <strong>in</strong><br />
Table 2.<br />
<strong>The</strong> Determ<strong>in</strong>ation <strong>of</strong> Optimum pH <strong>of</strong> Rhodam<strong>in</strong>e<br />
Adsorption by Chit<strong>in</strong> and chitosan<br />
pH is one <strong>of</strong> factors that <strong>in</strong>fluence<br />
adsorption process. From data <strong>of</strong> determ<strong>in</strong>ation <strong>of</strong><br />
colour essence <strong>of</strong> rhodam<strong>in</strong>e textile that been<br />
adsorbed because <strong>of</strong> pH <strong>in</strong>fluence. Figure 3 shows<br />
pH <strong>in</strong>fluence toward adsorption <strong>of</strong> color essence <strong>of</strong><br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
rhodam<strong>in</strong> by chit<strong>in</strong> and chitosan for 30 m<strong>in</strong>utes. In<br />
chit<strong>in</strong> rhodam<strong>in</strong>e adsorption more <strong>in</strong>creases<br />
significantly at pH 2-5. After pH 5, colour essence<br />
<strong>of</strong> rhodam<strong>in</strong> that been adsorbed more decreases,<br />
rhodam<strong>in</strong>e adsorption <strong>in</strong> chit<strong>in</strong> occurs because <strong>of</strong><br />
<strong>in</strong>teraction <strong>of</strong> amide group that be<strong>in</strong>g proton by N +<br />
group from rhodam<strong>in</strong>e.<br />
Figure 3 correlation between Rhodam<strong>in</strong>e that<br />
adsorbed (q) chit<strong>in</strong> with pH<br />
Figure 4 correlation between Rhodam<strong>in</strong>e that<br />
adsorbed chitosan (q) with pH<br />
Figure 4 shows that rhodam<strong>in</strong>e adsorption<br />
by kitosan. At pH 2-3 more <strong>in</strong>creases, but after pH<br />
4 color essence <strong>of</strong> rhodam<strong>in</strong>e that be<strong>in</strong>g adsorbed<br />
decreases. This is because chitosan has am<strong>in</strong>a<br />
(NH2) groups that has one set <strong>of</strong> dependent electron<br />
<strong>in</strong> atom N. This am<strong>in</strong>a group serves as lewis base<br />
by shar<strong>in</strong>g its set <strong>of</strong> dependent electron, so that at<br />
pH acid/base will enable protonation very<br />
small/even doesn’t occur. Accord<strong>in</strong>g to Suhardi<br />
(1993) that am<strong>in</strong>a groups at chitosan, can fasten<br />
color essence because chitosan has character <strong>of</strong><br />
cationic so that <strong>in</strong> acid condition am<strong>in</strong>a groups<br />
(NH2) will be protoned become (NH3 + ). <strong>The</strong> more<br />
<strong>in</strong>creas<strong>in</strong>g <strong>of</strong> rhodam<strong>in</strong> that is adsorbed, the more<br />
many am<strong>in</strong>a groups that is protoned (Chiou, 2003).<br />
<strong>The</strong> Determ<strong>in</strong>ation <strong>of</strong> Optimum Contact Time<br />
toward Rhodam<strong>in</strong>e Adsorption by Chit<strong>in</strong> and<br />
Chitosan<br />
<strong>Study</strong> about this <strong>in</strong>fluence <strong>of</strong> contact time aims to<br />
know optimum contact time at adsorption <strong>of</strong> color<br />
essence <strong>of</strong> rhodam<strong>in</strong>e by chit<strong>in</strong> and chitosan.<br />
Contact time is varied from 15, 30, 45, and 60<br />
Proceed<strong>in</strong>g Book 583
<strong>The</strong> First International Sem<strong>in</strong>ar on Science and Technology<br />
January 24, 2009<br />
m<strong>in</strong>utes with compound volume 20 ml at pH 5<br />
(chit<strong>in</strong>) and pH 3 (chitosan). In Figure 5 and 6 show<br />
the <strong>in</strong>fluence <strong>of</strong> time toward rhodam<strong>in</strong> adsorption<br />
by Chit<strong>in</strong> and chitosan. <strong>The</strong> longer contact time, the<br />
more color essence that is absorbed by Chit<strong>in</strong> and<br />
chitosan, then further occurs decreas<strong>in</strong>g <strong>of</strong><br />
adsorption <strong>of</strong> color essence <strong>of</strong> rhodam<strong>in</strong>.<br />
Figure. 5 correlation between contact time with<br />
rhodam<strong>in</strong>e that adsorbed by chit<strong>in</strong> (q)<br />
Figure. 6 correlation between contact time with<br />
rhodam<strong>in</strong>e that adsorbed by chitosan<br />
(q)<br />
This shows that stability has been<br />
achieved. And the adsorption tends to decrease after<br />
it goes on for 30 m<strong>in</strong>utes, probably it occurred<br />
resulted <strong>in</strong> <strong>in</strong>teraction <strong>of</strong> adsorben with adsorbat<br />
that too much full. Contact time <strong>of</strong> 30 m<strong>in</strong>utes<br />
seems have the most optimum adsorption.<br />
<strong>The</strong> Adsorption by Chit<strong>in</strong> and chitosan with<br />
Variation <strong>of</strong> Rhodam<strong>in</strong> Concentration<br />
Rhodam<strong>in</strong>e adsorption by chit<strong>in</strong> and chitosan is<br />
conducted by variation <strong>of</strong> concentration between<br />
60, 120, 180, 240, and 300 ppm with pH 5 for<br />
Chit<strong>in</strong> and pH 3 for kitosan dur<strong>in</strong>g 30 m<strong>in</strong>utes.<br />
Maximum rhodam<strong>in</strong> adsorption by Chit<strong>in</strong> and<br />
kitosan are 5.695 mg/g and 6.549 mg/g (based on<br />
isotherm Langmuir equalization). At rhodam<strong>in</strong><br />
adsorption by Chit<strong>in</strong> can be seen from Figure 7 and<br />
chitosan from figure 8, adsorbtion outcome shows<br />
that <strong>in</strong>creas<strong>in</strong>g <strong>of</strong> chitosan adsorb<strong>in</strong>g power occurs<br />
with <strong>in</strong>creas<strong>in</strong>g <strong>of</strong> rhodam<strong>in</strong> solution concentration.<br />
<strong>The</strong> bigger rhodam<strong>in</strong> concentration, kitosan power<br />
tends to more <strong>in</strong>crease, and at certa<strong>in</strong> concentration<br />
that results <strong>in</strong> equal condition thus the <strong>in</strong>creas<strong>in</strong>g <strong>of</strong><br />
concentration doesn’t <strong>in</strong>fluence adsorb<strong>in</strong>g power<br />
anymore.<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
Figure 7 correlation between rhodam<strong>in</strong>e that<br />
adsorbed (q) by chit<strong>in</strong> with various<br />
concentration <strong>of</strong> rhodam<strong>in</strong>e<br />
Figure 8. corelation between rhodam<strong>in</strong>e that<br />
adsorbed<br />
(q) by chitosan with various concentration<br />
<strong>of</strong><br />
rhodam<strong>in</strong>e<br />
Accord<strong>in</strong>g to Robert (1992) chit<strong>in</strong> has –<br />
NHCOCH3 (amida) active groups, and <strong>in</strong>volves<br />
<strong>in</strong>teraction <strong>of</strong> hydroxyl (-OH) group as active site<br />
that fasten the color essence and chitosan has either<br />
hydroxyl (-OH) active groups or am<strong>in</strong>a (NH2).<br />
Interaction <strong>of</strong> Chit<strong>in</strong> and chitosan with<br />
rhodam<strong>in</strong>e can occur because <strong>of</strong> electrostatic<br />
<strong>in</strong>teraction (Longh<strong>in</strong>otti, dkk., 1998). Electrostatic<br />
<strong>in</strong>teraction <strong>of</strong> chit<strong>in</strong> and rhodam<strong>in</strong>e due to a set <strong>of</strong><br />
dependent electron at N-amida (-NHCOCH3)<br />
groups that is shared at N-rhodam<strong>in</strong>e (N + -(C2H5)2)<br />
groups, while electrostatic <strong>in</strong>teraction at chitosan<br />
because <strong>of</strong> groups from rhodam<strong>in</strong> -COO -<br />
(Annadurai, 2002) and (-NH3 + ) positive groups at<br />
chitosan. So that rhodam<strong>in</strong>e adsorption by chitosan<br />
more <strong>in</strong>creases by more many am<strong>in</strong>a groups that is<br />
protoned (Chiou, 2003).<br />
Result <strong>of</strong> the study shows alteration <strong>of</strong> the<br />
color occurr<strong>in</strong>g after adsorption process. <strong>The</strong> color<br />
<strong>of</strong> Chit<strong>in</strong> that is formerly yellowish-white changes<br />
to red and the color <strong>of</strong> chitosan that is formerly<br />
brownish-white changes to red. While rhodam<strong>in</strong>e<br />
solution is formerly red changes to more<br />
transparent (bright). That alteration suggests that<br />
rhodam<strong>in</strong>e <strong>in</strong> the solution has been absorbed by<br />
either chit<strong>in</strong> or chitosan.<br />
Proceed<strong>in</strong>g Book 584
<strong>The</strong> First International Sem<strong>in</strong>ar on Science and Technology<br />
January 24, 2009<br />
ISBN : 978 – 979 – 19201 – 0 – 0<br />
<strong>The</strong> prediction <strong>of</strong> <strong>in</strong>teraction that occurs between chit<strong>in</strong> and chitosan with rhodam<strong>in</strong>e is:<br />
• Chit<strong>in</strong>-N (amida)+ + N(C2H5)2-rhod →Kit-(amida)N + N(C2H5)2-rhod<br />
• Chitosan-NH3 + + - OOC-rhod→Kit-NH3 + + - OOC-rhod<br />
Based on estimation us<strong>in</strong>g isotherm Langmuir<br />
equalization, maximum capacity <strong>of</strong> rhodam<strong>in</strong> that is<br />
absorbed by Chit<strong>in</strong> and chitosan is 5.695 mg/g and<br />
6.549 mg/g. this suggests that chitosan is more<br />
effective than chit<strong>in</strong> for adsorb<strong>in</strong>g rhodam<strong>in</strong>e.<br />
Conclusion<br />
<strong>The</strong> result <strong>of</strong> extraction is ga<strong>in</strong>ed whitecolour<br />
chit<strong>in</strong> and white-grayish chitosan obta<strong>in</strong>ed<br />
conta<strong>in</strong>ed 70.48%. <strong>The</strong> optimum adsorption pH <strong>of</strong><br />
chit<strong>in</strong> <strong>in</strong>to rhodam<strong>in</strong>e occurs <strong>in</strong> pH <strong>of</strong> 5 and the<br />
optimum adsorption <strong>of</strong> chitosan <strong>in</strong>to rhodam<strong>in</strong>e <strong>in</strong><br />
pH 3. Time <strong>of</strong> adsorption optimum contact <strong>of</strong><br />
rhodam<strong>in</strong>e by chit<strong>in</strong> and chitosan occurs <strong>in</strong> 30<br />
m<strong>in</strong>utes. <strong>The</strong> maximum adsorption capacity chit<strong>in</strong><br />
<strong>of</strong> rhodam<strong>in</strong>e 5.69 mg/g and the maximum<br />
adsorption capacity chitosan <strong>of</strong> rhodam<strong>in</strong>e 6.55<br />
mg/g. it is concluded that chitosan more effective as<br />
adsorbent rhodam<strong>in</strong>e than chit<strong>in</strong>.<br />
References<br />
Annadurai, G., 2002, Adsorption <strong>of</strong> Basic Dye on<br />
Strongly Chelat<strong>in</strong>g Polymer: Batch<br />
K<strong>in</strong>etics Studies, Journal Iranian Polymer.<br />
vol 11, no. 4<br />
Benjakul, S. dan P. Shophanodora, 1993, Chitosan<br />
Production from Carapace and Shell <strong>of</strong><br />
Black Tiger Shrimp, ASEAN food J.vol 8,<br />
no. 4<br />
Chiou, M., ho, P., dan Li, H., 2003, Adsorption<br />
Behavior <strong>of</strong> Dye AAVN and RB4 <strong>in</strong> Acid<br />
Solutions on Chemically Cross- Unked<br />
Chitosan Beads, J.Chm. Inst. Chem, Engrs,<br />
PP, Taiwan<br />
Fessenden & Fessenden, 1991, Kimia Organik,<br />
edisi ketiga, Erlangga, Jakarta<br />
Filipkowska, U., 2007, Adsorpstion and desorption<br />
Efficiency <strong>of</strong> Black 8 and Black 5 onto<br />
chit<strong>in</strong> and chitosan, Polish Chit<strong>in</strong> Society,<br />
Monograph XII, Olsztyn<br />
Ism<strong>in</strong><strong>in</strong>gsih, R., 1973, Pengantar Kimia Zat Warna,<br />
ITB, Bandung<br />
Longh<strong>in</strong>otti, E., Pozza, F., Furlan, L., de M, M. de<br />
N., Sanchez, Klug, M.,<br />
Laranjeira, M. C. M., and Favere, V. T.,<br />
1998, Adsorption <strong>of</strong> Anionic Dyes on the<br />
Biopolymer Chit<strong>in</strong>, J. Braz. Chem. Soc.,<br />
Vol. 9, no. 5, Brazil<br />
Margan<strong>of</strong>, 2003, Potensi Limbah Udang Sebagai<br />
Penyerap Logam Berat (Timbal,<br />
Kadmium, dan Tembaga) Di Perairan,<br />
IPB, Bogor<br />
Mekawati, Facriyah, E., and Sumardjo, D., 2000,<br />
Aplikasi Kitosan Hasil Transformasi Kit<strong>in</strong><br />
Limbah Udang (panaeus merguensis)<br />
untuk Adsorpsi Ion Logam Timbal, Jurnal<br />
sa<strong>in</strong>s dan Matematika., vol. 8(2)<br />
Moeljanto,1984, Penangkapan Ikan Segar, PT<br />
Penebar Swadaya, Yogyakarta<br />
Muzzarelli, R. A. A., 1985, Chit<strong>in</strong>, New York :<br />
Pengaman Press<br />
Robert, G. A. F.,1992, Chit<strong>in</strong> Chemistry, <strong>The</strong><br />
Macmillan Press, London<br />
Sastrohamidjojo, H., 1991, Spektroskopi, Liberty,<br />
yogyakarta<br />
Suhardi, 1993, Khit<strong>in</strong> dan Khitosan, Yogyakarta :<br />
PAU Pangan dan Gizi UGM<br />
Tokura, S. and N.N, 1995, Specification and<br />
Characterization <strong>of</strong> Chit<strong>in</strong> and Chitosan,<br />
Collection <strong>of</strong> work<strong>in</strong>g papers.28,<br />
Universiti Kebangsaan Malaysia<br />
Proceed<strong>in</strong>g Book 585