An electrochemical acid concentration system using conducting polymer electrodes

The proton permeability of polyanion-doped polypyrrole membranes was studied by measuring the ionic currents flowing across the membranes and the amounts of protons transferred. By utilizing the proton permeability and redox properties of polypyrrole films, an acid concentration system was constructed using polypyrrole membrane electrodes. The acid concentration was achieved by repeating redox reactions of the polypyrrole membrane electrodes in a specially designed electrochemical cell. As a result of the redox reactions, protons were transferred through the membrane electrodes, without causing chemical and physical changes in the polypyrrole films, by applying a d.c. voltage of 0.8 V.