Swelling and electric-sensitive characteristics of poly-cation PVA hydrogel membrane in aqueous NaCl solution

摘要

A novel polycation PVA (CAPVA) hydrogel membrane crosslinked with glutaraldehyde has been prepared by quaternizing polyvinyl alcohol (PVA) with glycidyltrimethylammonium chloride (GTMAC) and using KOH as catalyst under ultrasound, and its swelling and electric-sensitive characteristics in aqueous NaCl solution were studied. The results indicated that the water take-up of CAPVA hydrogel membrane decreased as the concentration of NaCl solution increased. The hydrogel membrane bended toward the anode under a non-contact dc electric field in NaCl aqueous solution. The bending speed and deflection of the hydrogel membrane increased with the increasing of applied voltage. The electric-sensitive characteristic of the hydrogel membrane was also affected by the electrolyte concentration of external NaCl solution, and there is a critical ionic strength of 0.02 at which its bending speed and equilibrium strain reached the maximum value. Under a cyclically varying electric field, the hydrogel membrane exhibited a good reversible bending behavior.