Polyelectrolyte hydrogels of chitosan and polyacrylamide: A comparison of electroactive characteristics

In this paper, studies on polyelectrolyte hydrogels of both anionic and cationic type are reported. Partially hydrolysed polyacrylamide-polyvinyl alcohol interpenetrating polymer (IPN) has been synthesized as the anionic hydrogel and chitosan-polyvinyl alcohol interpenetrating polymers have been synthesized as the cationic one, both through a simultaneous IPN method. In both cases, the crosslink densities are varied and investigated for their swelling behaviour and rheological properties. The stimulus sensitivity of the hydrogels is determined by subjecting them to applied electric fields. The responses of the various hydrogels are correlated with the shear moduli, the crosslink densities and the swelling behaviour. An interesting observation of simultaneous bending of multiple gel slabs in different directions upon the application of the electric field is also reported.