Research Theme 3 - Functional Polymer Research

Research Theme - 3

Creation of Anisotropic Conducting Electrolyte Membranes Using an Ion Beam Technique

 By irradiation of swift heavy ions, polymer films have large dameges with ten to a few hundred nanometer in diameter along the ion-path through the films which is called "latent track". This damage of the films are sufficient for chemical etching in an alkaline solution and oxidative etchants such as NaClO, resulting in the formatin of through-holes with an aspect ratio (the ratio between a film thieckness and a hoe diameter) greater than 1000.
We are conducting the preparation of electrolyte membranes by two approaches. One utilizes the latent tracks. After the irradiation of ion beams, we directly grafted the polystyrene into the latent tracks, which is followed by sulfonation of the grafted polystyrene. Another method utilizes the ion etched tracks. After irradiation, first, the latent tracks are etched out. Then, the polystyrene is deposited into the etched pores. Then, sulfonation of the polystyrene leads to the anisotropically conducting polymer electrolytes, consisting of highly conductive cylindrical layers surrounded by a thermally stable matrix region.