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

Table 2

Process parameters used to study the effect of polymerisation temperature and postsynthesis treatment (freezing time and number of freeze-thaw cycles) on the responsiveness of LHL Cht-PVP-Gen hydrogels.

Gel code	Polymerisation temperature (°C)	Freezing time at −10°C; (h)
LHL1	30	72
LHL2	30	3 freeze-thaw cycles: 24 h freezing and 3 h thawing each
LHL3	40	72
LHL4	40	3 freeze-thaw cycles: 24 h freezing and 3 h thawing each
LHL5	50	72
LHL6	50	3 freeze-thaw cycles: 24 h freezing and 3 h thawing each

Sample composition: 0.2 mL Cht solution, 0.5 mL PVP solution, and 0.004 mL Gen solution; average molar ration of Cht : PVP : Gen is 1 : 49 : 7.