Application of a distributed impedance model in the analysis of conductingpolymer films

The problem analysed is whether the electrochemical transfer in the doping of conducting polymer electrodes must be described as a macroscopic resista nce localised at the outer boundaries of the polymer layer, or by a distrib uted process inside the film region. Impedance measurements of poly(thiophe ne-3-acetic acid) film in its oxidised state are reported for various value s of pH in solution. The analysis shows that the observed response consists on the coupling, throughout the polymer film, of the transfer resistance w ith other conduction and polarisation processes. This is interpreted as evi dence of a distributed charge-transfer resistance in the internal polymer/s olution interface. (C) 2000 Published by Elsevier Science S.A.