Actuator-Like Hydrogels Based on Conductive Chitosan

Abstract

Intrinsically conducting polymers are of great interest for a large number of applications. But among major drawbacks are their low solubility in common solvents and their poor mechanical properties. Elaboration of composites associating a matrix, bringing its mechanical properties, and polyaniline, as the conducting polymer is a way of overcoming these disadvantages. Chitosan-graft-polyaniline copolymers were synthesized by simple oxidative method. The grafting reaction was quite total and it was found that the copolymers crosslinked to yield a composite hydrogel in which the polyaniline was homogeneously embedded. The conductivity of precursor (block copolymer) and gels was found to be larger than 10-2 S.cm-1. The composite gels were characterized in terms of swelling and rheological properties. They can be classified as "superabsorbent" hydrogels and the swelling is reversible. The composite gels were then successfully used as actuators.