Electrochemical formation of polyethylenedioxithiophene in aqueous micellar solution

The electrochemical polymerisation of 3,4-ethylenedioxythiophene (EDT) is studied in aqueous solutions containing a non-ionic micellar surfactant. The kinetics of the electropolymerisation process is investigated under potentiostatic conditions at stationary and rotating disk electrodes in electrolytes with different composition. The polymerisation currents are controlled by both charge transfer and transport limitations. The values of the diffusion coefficients obtained from rotating disk experiments are found to be independent of the electrolyte composition. The potential dependence of the charge transfer currents is not influenced by the non-ionic surfactant. A strong inhibition effect of the polymer growth takes place when increasing the surfactant concentration. This suggests a significant role of adsorption and double layer phenomena in the electropolymerisation kinetics.