Effect of reduction temperature on electrode formation and performance of ionic polymer metal composites

Abstract

Ionic polymer metal composite (IPMC) was prepared by electroless plating method on NafionTM film. In this study, the effect of reduction temperature of electroless plating process was examined on the impedance, surface resistivity, and IPMC performance. At high first reduction temperature OH- anions appears to penetrate deep into the negatively charged polymer membrane and produce in-depth Platinum (Pt) deposition with low impedance. The second reduction temperature greatly affects the surface morphology of Pt electrodes and surface resistivity. Low impedance and surface resistivity result in better performance of IPMC in terms of tip displacement, tip force, and rate of response. The Platinum electrode of IPMC was post-treated by additional gold (Au) coating employing ion coater or dc sputter. It was observed that coarse and large Au polycrystals with the size of 0.5 - 2.5 μm were formed on Pt layer in the case of dc sputtering, whereas ion coating produced much smaller Au polycrystals filling the gaps between Pt polycrystals effectively. The IPMC treated by ion coating demonstrated the improved actuation behavior.