Proton Conductivity and Oriented Structure of Nafion Thin Films on the Au-Deposited Surface and MgO Substrate

Abstract

In-plane proton conductivity and interfacial structure of Nafion thin films on the Au-deposited surface and MgO(100) substrate were investigated. Proton conductivity on both Au-deposited and MgO surfaces clearly decreased with decreasing the thickness except the conditions of 80% and 95% relative humidity on the Au-deposited surface. Proton conductivity drop on the MgO substrate was much heavier than that on the Au-deposited surface. Highly oriented structure was observed in both Nafion thin films on the Au-deposited surface and MgO surface by a p-polarized multiple angle incidence resolution spectrometry. While thickness dependent structural change was observed on the Au-deposited surface like the previous reported Nafion thin films on the Pt-deposited surface, thickness dependence of the structural change was not observed markedly on the MgO substrate.