Electrical behavior of chitosan and poly(hydroxyethyl methacrylate) hydrogel in the contact system

Semi-interpenetrating polymer networks (semi-IPNs), as polymer hydrogels composed of chitosan and poly(hydroxyethyl methacrylate) (PHEMA), exhibiting electrical-sensitive behavior, were prepared. The swelling behavior of the chitosan/PHEMA hydrogels was studied by immersing the gels in various concentrations of aqueous NaCl solution. The electrical responses of the semi-IPN hydrogel, in applied electric fields, were also investigated. When the semi-IPN hydrogels were swollen, where one electrode was placed in contact with the gel and the other fixed 30 mm apart from one, they exhibited bending behavior on the application of an electric field on a contact system. The electroresponsive behavior of the present semi-IPN was also affected by the electrolyte concentration of the external solution. The semi-IPN also showed various degrees of increased bending behavior depending on the electric stimulus. (C) 2004 Wiley Periodicals, Inc.