Browsing by Author "Telila, Gezahegn"

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    Preliminary Investigations of the Electrochemical Behaviour of A Class of Conducting Polymers
    (Addis Ababa Universty, 1994-06) Telila, Gezahegn; Tafesse, Fikru (PhD)
    The electrochemical polymerization of monomers of pyrrole, thiophene, and aniline on platinum and glassy carbon electrodes was carried out with dc cyclic voltammetric technique. The oxidation peak potentials for both the monomers and the polymer films in different base electrolytes were determined by using dc cyclic voltammetry. The redox reversibility of equimolar concentrations of the (Fe (CN) 61 4-/3- couple in 0.1 M KCl on polymer coated electrodes has been compared with that on bare platinum and glassy carbon electrodes with dc cyclic voltammetry. The polymer coated electrodes have shown wider peak separations compared to the bare electrodes. Higher or lower peak currents were observed for the redox reaction of (Fe(CN)6 14-/3- systems in 0.1 M KCl depending upon the type of polymer films and the nature of base electrolytes used in the electrochemical polymerization process. The diffusion coefficients of [Fe(CN)614- and [Fe(CN)6l 3- in 0.1 M KCl were evaluated on polymer coated electrodes from rotating disk electrode experiments. The results were compared with the diffusion coefficients of these electroactive species on bare platinum and glassy carbon electrodes. These results on the bare electrodes are in good agreement with literature values. Attempts have also been made to correlate the diffusion coefficients of [Fe(CN)61 4-/3- systems on polymer coated electrodes with the type of polymer film and the nature of base electrolytes.