Electrical sensitivity and mechanical properties of fast responsive PAMPS-PAA-PVA T-IPN hydrogels

Abstract

Macroporous ternary-interpenetrating polymer network (M-T-IPN) hydrogels composed of poly(acrylic acid) (PAA), poly(2-acrylamido-2-methyl propyl sulfonic acid) (PAMPS), and poly(vinyl acohol) (PVA) were synthesized by two steps of polymerization using PEG6000 as a pore-forming agent. By selectively washing away the PVA component, a macroporous structure was formed homogeneously in the hydrogels. The M-T-IPN hydrogels exhibited excellent compressive strength, and the maximum compressive strength was about 12.0 MPa. The bending behaviors of the M-T-IPN hydrogels in an electric field were investigated. When deionized water swollen samples were placed between a pair of electrodes in NaCl solutions, the M-T-IPN hydrogels showed a significant bending behavior upon the application of an electric field. The hydrogels bend toward the cathode when the concentration of polyanions in interior hydrogels is higher than the concentration of NaCl in exterior solutions. In contrast, the hydrogels bend toward the anode when the concentration of polyanions in interior hydrogels is lower than the concentration of NaCl in exterior solutions. © 2011 Wiley Periodicals, Inc.