ELECTROCHEMICAL FORMATION OF POLYANILINE IN SELENIC ACID

The electrochemical formation of polyaniline (PAn) was investigated in selenic acid. The cyclic voltammetry of selenate in the potential win dow from -0.15 to 0.8 V, indicates that the electropolymerization of a niline is not affected by the oxidizing ability of selenic acid. The g rowth rate of PAn observed at a potential of 0.8 V in a solution of 0. 1 M aniline in 0.2 M H2SeO4 was comparable with that in 0.2 M H2SO4. H owever, the PAn growth in H2SeO4 during successive potential cycles be tween -0.15 and 0.8 V was much lower than that in H2SO4. In cyclic vol tammograms, the first reduction peak for PAn was enhanced by the prese nce of selenate ions, possibly due to the deposition of elemental sele nium catalyzed by the polymer film. The deposition of metallic seleniu m on the PAn film greatly inhibited the growth of the polymer during s uccessive potential cycling between -0.15 and 0.8 V.