THE ELECTROCHEMICAL PROPERTIES OF OLIGOMERIC VIOLOGEN FILMS IMMOBILIZED BY POLYACIDS

A polyelectrolyte salt, which is insoluble in water, was obtained by e xchanging the bromide counterions with high molecular weight polymeric anions (poly(p-styrenesulphonic) and polyacrylis) in the polycondensa te of 1,4-dibromobutane and 4,4'-dipyridine. Films of this redox activ e polymer show good oxidation=reduction reversibility, retained even a fter 2000 cycles. The electrochemical accessibility of the redox centr es defends on the thickness of the polymer films and the composition o f the solution. In the thin films (<1 mu m) nearly 100% of the redox c entres are active. Atomic force microscopy studies show that these fil ms change their volume during redox cycling due to cations and solvent movement.