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 10–12, and the maximum swelling was observed at pH 10. 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.