Electropolymerization under galvanostatic conditions

G. Popkirov, E. Barsoukov, and R. N. Schindler [1997] Investigation of Conducting Polymer Electrodes by Impedance Spectroscopy during Electropolymerization under Galvanostatic Conditions, J. Electroanal. Chem. 425, 209-216. 

Polymeric salts of the poly(3,4-cycloalkylthiophene)s were obtained by electropolymerization in a divided compartment cell at 25°C in acetonitrile or nitrobenzene as solvent. The monomer and electrolyte concentrations were 0.01 and 0.1 mol/1, respectively. The optimum current density under galvanostatic conditions was found to be 2 mA/cm. Chemical polymerizations were performed using iron trichloride in acetonitrile or chloroform as oxidizing agent. 

Since the initial reports, electropolymerization of pyrroles has become a routine matter, and films have been prepared under both potentiostatic and galvanostatic conditions on a large number of substrates [213,214] and using various electrolytes. Generally, polymerization onto noble metals gives smoother, more adherent films than onto materials such as ITO or semiconductors [213]. The best depositions are obtained from oxidation of 0.1 M pyrrole in AN-f 0.1 M tetralkylammonium paratoluensulfonate [215]. With this anion the oxidative cycle involves 0.4 electrons per pyrrole ring [215]. 

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