Conductivity of novel, thin-film, heterogeneous polymer electolyte systems

Abstract

Over the last few years polymer electrolytes have generated much interest as potential components in devices such as batteries and smart windows. Some new systems synthesised recently have been proved to be excellent candidates for the preparation of thin films, especially Langmuir-Blodgett (LB) films. This technique enables the production of single- or multi-molecular layers of precisely known thickness. The work in this paper concentrates on the investigation of a bilayer structure composed of two different types of polyether-alkyl polymer electrolyte utilising the alternate-layer LB technique. We have demonstrated the viability of producing bilayer structures 19 molecular layers (approximately 450 Å) thick. In addition, samples prepared by using ions in the subphase exhibit higher conductivities than those without added ions, demonstrating that ion uptake from the subphase is taking place. Also, conductivity normal to the layer planes was extremely low in contrast to the higher values obtained on bulk samples. This demonstrates that ions are unable to cross the alkyl layers in the highly ordered LB system.