Diffusion in polyvinylpyrrolidone hydrogels prepared by radiation technique

Abstract

Hydrogels of polyvinylpyrrolidone (PVP) were prepared by using polymer aqueous solutions at 10% w/w and gamma radiation. The swelling experiments were carried out in water at 30° and followed by weighing. The concentration of effective chains ( V e) and the number-average molecular weight between crosslinks were calculated by considering the chain-end effects. Diffusion and partition coefficients of rhodamine dye were calculated by following the diffusion of the solute out of PVP gel cylinders into water at 30°. The effect of gel structure on diffusion was studied by preparing gels with various radiation doses and PVP molecular weights. V e increased with rise in radiation dose, indicating clearly that hydrogels of controlled structure can be prepared. The molecular weight of the polymer altered the gel structure, but these effects were more pronounced at lower absorbed radiation doses. Diffusion coefficient decreased with increase in radiation dose showing the influence of gel structure on solute diffusion.