Ion transport membranes based on conducting polymers

Polypyrrole membranes containing four different dopant ions were prepared galvanostatically from aqueous solutions of pyrrole (0.1 M) and the appropriate counter ion salt (0.1 M). The transport of mono-valent cations through each membrane was achieved by applying a potential gradient across the membranes. The influence of a number of set up parameters on the flux of K⁺ ions across a PPy/pTS membrane was assessed, as well as the relative selectivities of the four membrane types for the mono-valent cations; Li⁺, Na⁺, K⁺, Rb⁺ and Cs⁺.