Electroresponsive Behavior of 2-Hydroxypropyltrimethyl Ammonium Chloride Chitosan Hydrogel Under DC Electric Field

Abstract

A novel polycationic chitosan hydrogel, 2-hydroxypropyltrimethyl ammonium chloride chitosan hydrogel (HACC hydrogel), was prepared by the introduction of quaternized groups with glycidyltrimethylammonium chloride (GTMAC) and epichlorohydrin as crosslinker, and its swelling properties and electroresponsive behavior in aqueous NaCl solutions were studied. The results indicated that the water uptake ability of the hydrogel decreased with the increasing ionic strength of aqueous NaCl solution. The hydrogel swollen in the NaCl solution bent toward the anode under the non-contact dc electric fields, and its bending speed and equilibrium strain increased with the increasing of applied voltage. The electroresponsive behavior of the hydrogel was also affected by the electrolyte concentration of external NaCl solution, and there is a critical ionic strength of 0.15 where the maximum equilibrium strain of the hydrogel occurs. By changing the direction of the applied potential cyclically, the hydrogel exhibited good reversible bending behavior.