Structure of a Graphene-Modified Electroactive Polymer for Membranes of Biomimetic Systems: Simulation and Experiment

Abstract

A model is proposed that describes the structure of water filled Nafion-graphene composite forming the body of an electroactive polymer membrane for actuators of biomimetic systems able to work in air and a liquid medium. The model predicts the growth of the ionic conductivity with increasing concentration of a graphene modifier, which is due to that the size of a part of clusters of the Nafion framework containing hydrophobic graphene flakes enlarges together with the pore size. Then the optimal concentration of the graphene modifier is reached, which provides the maximum ionic conductivity and actuation ability of the membrane as well as its elastic properties. The possibility of introducing into Nafion the modifier amount needed to improve the actuator operation is experimentally tested.