Genipin Cross-Linked Chitosan-Polyvinylpyrrolidone Hydrogels: Influence of Composition and Postsynthesis Treatment on pH Responsive Behaviour

Figure 2

Relative volumetric swelling of samples listed in Table 1 screened optically in pH 2 (glycine) buffer. Washed gels were initially contracted with pH 7 phosphate buffer solution. Gels were then removed from solution (time zero on the graph) and pH 2 buffer was added.