Formation of a gold nanoparticle layer for the electrodes of ionic polymer–metal composites by electroless deposition process

We investigated the reduction conditions of Au-deposited ionic polymer–metal composites (IPMCs) to form gold (Au) electrodes on the surface of a sulfonated tetrafluoroethylene-based fluoropolymer-copolymer (Nafion), as the ionic polymer membrane, through the electroless deposition of nanoparticles (NPs) layer. The size and distribution of Au NPs formed on the surface of the ionic polymer varied depending on the concentration from 0.25 to 1 mM of sodium L-ascorbate aqueous reducing agent solution and reduction duration of up to 6 hrs. The size and distribution of the Au NPs with different reduction conditions were confirmed to be closely related to the thickness and uniformity of the Au IPMC electrodes. Changes in the Au NP layer formed on the surface of the Nafion entailed changes in the electrical resistance and electromechanical behavior of the IPMCs with Au electrodes.