2.1.8.2. Absorbency Under Load (AUL) - BADA
2.1.8.2. Absorbency Under Load (AUL) - BADA 2.1.8.2. Absorbency Under Load (AUL) - BADA
3.3.Ⅰ. Effect of Buffer solution The change of the equilibrium swelling degree of AP-hydrogel as a meaning of the pH of the buffered solution is shown in Figure 23. In the range of pH 3–6.0 the equilibrium swelling capacity was incredibly low and showed a little change with pH, but at pH 6.0 was started to rise of the equilibrium swelling degree. In AP-hydrogel a jump was observed from pH 7 to pH 9. Therefore the water uptake capacity increased from 43 g water / g dry gel at pH 3 to about 115 g water / g dry gel at pH 9. In the present work, the swelling of the modified AP-hydrogel increased significantly when the pH raised in the alkaline buffer solution (pH 9) at 25±2 o C. The increase in water uptake at pH 9 might be due to further increase in the no net electrical charge at the surface of the albumin protein. It seems that around the pH 9 might be the isoelectric point (pI) of EDTAD AP-hydrogel. It should be mentioned that increasing swelling capacity of hydrogel is not directly related to the binding of water molecules to ionized carboxyl groups. It could be related to untangling of the protein chain due to electrostatic repulsion inside the hydrogel network, resulting in maximum water absorption. Swelling (g/g) 150 120 90 60 30 0 0 2 4 6 8 10 12 14 pH Figure 23. Effect of pH in buffer solutions on swelling capacity of the AP-hydrogel 49
3.4.Ⅰ. Kinetics of Swelling Figure 24 illustrates the swelling kinetic of EDTAD-AP hydrogel in deionized water as a function of time. Swelling behavior of the AP-hydrogel was shown during the 24 h a maximum water uptake of 296 g water/g dry gel after 24 h at room temperature. The maximum rate of swelling was obtained during first hour and then the slope increased very slowly up to 24 hours. In fact, the swelling kinetic of superabsorbent is better to determine up to first hour of immersion. Moreover the equilibrium swelling rate of albumin protein-based hydrogel is comparable to synthetic hydrogels such as polyacrylate (ALCOGUM L520). Our results showed that during the first 5 minutes, water uptake of AP-hydrogel and polyacrylate are equal but polyacrylate will overtake little by little from the AP-hydrogel after about 30min to 1hour of immersion in deionized water (Fig. 25). This distinction might be due to the presence of significant amounts of residual folded structure in the crosslinked AP-hydrogel. Swelling (g/g) 350 300 250 200 150 100 50 0 0 10 20 Time (h) Figure 24. Kinetics of swelling of AP-hydrogel at 25 o C 50 30
- Page 10 and 11: 22- Effect of Glutaraldehyde concen
- Page 12 and 13: 1 INTRODUCTION Superabsorbent hydro
- Page 14 and 15: 1.1. Definition of Superabsorbency
- Page 16 and 17: 1.3.1. Protein Structure Protein fo
- Page 18 and 19: 2- Side chains of polar residues wi
- Page 20 and 21: 1.3.3. Ovalbumin , Good Source for
- Page 22 and 23: One of the paper preparation proces
- Page 24 and 25: ……………………………
- Page 26 and 27: 1.5. The Thermodynamic of Protein F
- Page 28 and 29: In order to chemical modification o
- Page 30 and 31: The swollen crosslinked polymer may
- Page 32 and 33: 1.7.1.3. Crosslinking by UV-Irradia
- Page 34 and 35: 1.7.2.1. Non-specific Crosslinking
- Page 36 and 37: 1.8. Determination the Degree of cr
- Page 38 and 39: These preparations contain consider
- Page 40 and 41: MATERIALS AND METHODS 2.1. Method o
- Page 42 and 43: ased on the solubility of the prote
- Page 44 and 45: 2.1.2.2. Determination of Zygomycet
- Page 46 and 47: 2.1.3. Modification of proteins Alb
- Page 48 and 49: The first step was weighted a 30 mg
- Page 50 and 51: 2.1.8.1. Centrifuge Retention Capac
- Page 52 and 53: Figure 17. Schematic of device used
- Page 54 and 55: Results showed the effect of ethano
- Page 56 and 57: Preparation of protein solution (1%
- Page 58 and 59: PART Ⅰ ALBUMIN SUPERABSORBENT HYD
- Page 62 and 63: Swelling (g/g) 300 200 100 0 1 0.01
- Page 64 and 65: Swelling (g /g ) 350 300 250 200 15
- Page 66 and 67: 3.8.Ⅰ. Effect of Temperature Prot
- Page 68 and 69: In this rearrangement the R─ grou
- Page 70 and 71: Calculations As a result by solving
- Page 72 and 73: In the present work, increasing the
- Page 74 and 75: In detail, Figure 36 shows the comp
- Page 76 and 77: Sample Table 5. Comparison of swell
- Page 78 and 79: The IZP-hydrogel compared with unmo
- Page 80 and 81: According to our results, the swell
- Page 82 and 83: REFERENCES 1- Fredric L.Buchholz &
- Page 84 and 85: 32- Alexander,. J, Colloid chemistr
3.4.Ⅰ. Kinetics of Swelling<br />
Figure 24 illustrates the swelling kinetic of EDTAD-AP hydrogel in deionized water as a function<br />
of time. Swelling behavior of the AP-hydrogel was shown during the 24 h a maximum water<br />
uptake of 296 g water/g dry gel after 24 h at room temperature. The maximum rate of swelling was<br />
obtained during first hour and then the slope increased very slowly up to 24 hours. In fact, the<br />
swelling kinetic of superabsorbent is better to determine up to first hour of immersion.<br />
Moreover the equilibrium swelling rate of albumin protein-based hydrogel is comparable to<br />
synthetic hydrogels such as polyacrylate (ALCOGUM L520). Our results showed that during the<br />
first 5 minutes, water uptake of AP-hydrogel and polyacrylate are equal but polyacrylate will<br />
overtake little by little from the AP-hydrogel after about 30min to 1hour of immersion in deionized<br />
water (Fig. 25). This distinction might be due to the presence of significant amounts of residual<br />
folded structure in the crosslinked AP-hydrogel.<br />
Swelling (g/g)<br />
350<br />
300<br />
250<br />
200<br />
150<br />
100<br />
50<br />
0<br />
0 10 20<br />
Time (h)<br />
Figure 24. Kinetics of swelling of AP-hydrogel at 25 o C<br />
50<br />
30
Change language