| Abstract: | The swelling capacity of poly(N-vinylimidazole) hydrogels in aqueous solutions and organic solvents was measured as a function of polymer network structure. In pure water, the swelling capacity decreases monotonously upon increasing the crosslinker ratio and the total comonomers concentration in the polymerization feed mixture. In methanol a similar behaviour was observed while in ethanol, the swelling capacity shows an abrupt change from large values to 0.01 grams of water per gram of dry gel, that is to say, PVI experience swollen-collapsed transitions with small changes of the gel crosslinking degree. Molecular weight of chains between crosslinks, determined from swelling measurements in methanol, scales with the product of the crosslinker and total comonomers concentrations in the feed mixture to m1.14-0.05. The dependence of the polymer solvent interaction parameter on the polymer concentration inside the swollen gel was also determined for water and ethanol. |
