The time-dependent FSC of the swollen cross-linked
hydrogels are presented in Fig. 9. The highest swelling
capacity was observed in CASXGLU while the lowest swelling
capacity was observed in CASXBTC. Although the results
indicate that swelling is time dependent but after
1 h, the increases in swelling of the hydrogels with increase
in time were not remarkable. This indicates that
equilibrium was achieved after 1 h. Similarly, the time
dependent swelling capacities of the hydrogels in saline solution are presented in Fig. 10. The results followed similar
swelling pattern among the hydrogels but with pronounced
reduction in swelling capacities compared with
the values recorded in deionized water. Also, progressive
increases in swelling were minimal after the 1 h, thus indicating
the time of equilibrium. There are three components
of pressures that maintain the swelling of a hydrogel when
equilibrium is reached. (I) The pressure due to dilution
which occurs as a result of the absorption of the solvent
(pdilution), (II) the osmotic pressure that occurs as a result
of the presence of ions in the hydrogel (pion) and (III) the
changes in the gel volume that results in an elastic network
pressure (pnet). At equilibrium,