Ellipsometric study of the polymeric surface films formed on platinum electrodes by the electrooxidation of phenolic compounds

Ellipsometric measurements were used to follow in situ the growth of polymeric films formed on platinum electrodes by the eletrooxidation of phenolic compounds from aqueous solutions. The optical results provide information on the physical properties of the films and on the kinetics of growth. The dependence of film thickness and properties on applied potential is explained by competitive processes of growth and dissolution. Growth is shown to be controlled by field-assisted electron transport through the film. A simple interpretation is advanced for the selective inhibition of halide-ion electrooxidation by the polymeric surface films.