pH-Sensitive Swelling of a Polyelectrolyte Complex Gel Prepared from Xanthan and Chitosan

Abstract

Swelling of a polyelectrolyte complex gel prepared from xanthan and chitosan was sensitive to the ambient pH. In NaOH solutions, the complex gel swelled at pH l0-12, and the maximum swelling was observed at pH l0. The gel also swelled in HCl solution at pH 0, though it dissolved at pH 0.2-1.0 in the course of swelling. In NaCl solutions and Carmody buffer solutions, the pH at which the maximum swelling occurred shifted to pH 8 though the equilibrium swelling ratio decreased.