CHARGE-TRANSPORT AND ION-TRANSPORT PROPERTIES OF POLYPYRROLE POLY(STYRENESULFONATE) POLY(3-OCTYLTHIOPHENE) BILAYERS

The electrochemical, electronic, charge-transport, and ion-transport p roperties of a conducting polymer bilayer, prepared using polypyrrole/ poly(styrenesulfonate) (PP/PSS) and poly(3-octylthiophene) (POT) have been investigated by cyclic voltammetry, optoelectro-chemistry, and a combination of electrochemical and gravimetric techniques using the el ectrochemical quartz crystal microbalance (EQCM). This PP/PSS:POT bila yer presents separate redox switching potentials demonstrating that ch arge is efficiently transferred through the inner PP/PSS layer to the POT outer layer. While the bilayer exhibits reversible redox processes for both components during rapidly repeated cyclic voltammetric scans , poising the potential at a highly reducing value (-1.2 V vs Ag/Ag+) for a sufficient time prior to starting a potential scan severely limi ted the redox processes of the PP/PSS inner layer. This is most likely due to inhibited counterion transport through the neutral POT outer l ayer.