The electrochemical polymerization of 3,4-ethylenedioxythiophene (EDT) was
studied in microemulsions containing polyoxyethylene-10-laurylether as a no
n-ionic micellar surfactant. This allows to increase the solubility of the
monomer in an aqueous solution. Thereby, the surfactant affects the transpo
rt of EDT. Capacity measurements and cyclic voltammetry on bare Pt show the
influence of the surfactant by adsorption on the metal, too. An adsorption
on the polyethylenedioxythiophene (PEDT) surface could not be proved. Comb
ined charge transfer and diffusion limitations control the electropolymeriz
ation kinetics at low monomer and surfactant concentrations. Charge transfe
r becomes limiting at high EDT concentrations. Apparent diffusion coefficie
nts and the charge transfer coefficient of the electrochemical reaction wer
e obtained from RDE experiments. The redox activity, UV/VIS spectra and sur
face morphology (from SEM pictures) depend on the polymerization potential
and the solution composition. Best films were obtained at low potentials in
LiClO4. At high potentials overoxidation of the polymer takes place, but a
n incorporation of the surfactant could not be detected. (C) 2000 Elsevier
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