the production of thymoquinone from thymol and carvacrol
the production of thymoquinone from thymol and carvacrol
the production of thymoquinone from thymol and carvacrol
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7.1.5. Pore Volume <strong>and</strong> Surface Area Measurement<br />
The specific surface areas <strong>of</strong> <strong>the</strong> adsorbents can be determined by applying <strong>the</strong><br />
Langmuir model equation for Type I iso<strong>the</strong>rm. Nitrogen physisorption iso<strong>the</strong>rms <strong>of</strong><br />
NaY zeolite, Cr NaY <strong>and</strong> Cr (salpn)-NaY were obtained. They were Type I iso<strong>the</strong>rms<br />
according to IUPAC classification. The micropore volume <strong>and</strong> size reduced apparently<br />
after modification also indicated that <strong>the</strong> metal complex was successfully introduced<br />
into <strong>the</strong> inner channels <strong>of</strong> Cr based catalyst. The results were summarized in detail in<br />
Table 7.3.<br />
Table 7.3. Surface area <strong>and</strong> micropore volume analysis<br />
Materials Langmuir surface<br />
area<br />
(m 2 /g)<br />
Micropore volume<br />
(cm 3 /g)<br />
(<strong>from</strong> Horvath-Kawazoe)<br />
NaY zeolite 807 0.34<br />
Cr NaY 801 0.27<br />
Cr(salpn)-NaY 536 0.22<br />
Surface areas were found to be between 536 <strong>and</strong> 807 m 2 /g as seen in Table 7.3.<br />
The Horvath-Kawazoe method can be applied for a quantitative determination <strong>of</strong> <strong>the</strong><br />
micropore volume. In <strong>the</strong> literature, it was frequently reported that <strong>the</strong> lowering <strong>the</strong> pore<br />
volume <strong>and</strong> surface area was <strong>the</strong> indication <strong>the</strong> metal complexes were present within <strong>the</strong><br />
zeolite cages (Varkey et al. 1998, Joseph et al. 2002).<br />
7.1.6. Thermal Analyses<br />
7.1.6.1. Differential Scanning Calorimetric Analysis <strong>of</strong> Lig<strong>and</strong><br />
The melting point <strong>of</strong> lig<strong>and</strong> (H2 salpn) was found by differential scanning<br />
calorimetric analysis (DSC). Melting point <strong>of</strong> lig<strong>and</strong> was found as 53 ºC<br />
( H = − 73.54 kJ/kg ) by differential scanning calorimetric (DSC) analysis as seen in<br />
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