2.1.8.2. Absorbency Under Load (AUL) - BADA

Sample
Furthermore, absorbency of EDTAD-AP hydrogel was also estimated in synthetic urine (970 ml
deionized water, 19.4 g urea, 8 g NaCl, 0.6 g CaCl2 anhydrous, 2.05 g MgSO4.7H2O) [47] . Result
showed that the EDTAD-AP hydrogel swelling capacity was decreased from 167 g water /g dry
gel in water to 44 g water/g dry gel when it was exposed to synthetic urine after 1 h at 37 O C
(Table.4 and Fig.27).
Swelling (g/g)
200
150
100
50
0
0 0.05 0.1 0.15 0.2
NaCl Concentration (mol/L)
Modified AP-hydrogel
Unmodified AP-hydrogel
Figure 26. Effect of various NaCl concentrations on swelling behavior of EDTAD-AP hydrogel and
unmodified AP- hydrogel
Table 4. Comparison of swelling rates of modified AP superabsorbent hydrogel in deionized water, normal
saline and synthetic urine (average results of 10 samples)
Deionized water Normal Saline Synthetic urine
1 min 1 hr 24 hr 1 min 1 hr 24 hr 1 min 1 hr 24 hr
AP-hydrogel 51.0 ± 8.3 137.3 ± 29.6 276.3± 19.6 29.5 ± 3.9 47.5± 4.4 56.7± 7.1 26.6 ± 2.0 39.2 ± 4.8 51.4 ± 4.9
52