Synthesis of polysaccharide hybrid gel in ionic liquids via radiation-induced crosslinking

Abstract

Recently, our research group reported the first synthesis of polysaccharide chemical gels, conducted in the absence of any crosslinking reagents, using ionizing radiation in carboxylate-based room temperature ionic liquids (RTILs). However, the maximum gel fraction of the cellulose gel produced using this methodology was a poor 14% and furthermore, its mechanical properties were too low to measure and insufficient for practical use as soft gel electrodes. In this work, the production of polysaccharide hybrid gels was investigated in RTILs, using ionizing radiation in an attempt to improve their production yields and mechanical properties. A radiation-crosslinked cellulose/chitosan hybrid gel in a RTIL was obtained, and an increase in the gel fraction was observed with an absorbed dose of up to 80%. The mechanical properties, biodegradability, and thermal stability were measured and found to be sufficient for practical use as soft gel electrodes. The electronic voltage response of the hybrid gel was evaluated in terms of electronic conductivity, curvature, and displacement. The cellulose/chitosan hybrid gel displayed favorable properties in terms of the formation yield and mechanical properties and thus, it is envisaged that this gel will find application in bio-devices and soft actuators.