Influence of substrate conductivity on electrochemical polymerization of O-methoxyaniline

The influence of substrate conductivity on electrochemical polymerization (ECP) of O-methoxyaniline on transparent conducting SnO2 and SnO2:F coated glass substrates has been investigated. In this work, transparent conducting SnO2 and SnO2:F coated glass substrates having different electrical conductivities were used as the substrates for the synthesis of poly (O-methoxyaniline) (POMA) thin films. These substrates were characterized by x-ray diffraction (XRD) measurements. The POMA thin films were synthesized on these substrates by ECP of O-methoxyaniline under cyclic voltammetric conditions. The POMA thin films were characterized by cyclic voltammetry, UV-visible spectroscopy, scanning electron microscopy (SEM) and electrical conductivity measurements. It was observed that the efficiency of the polymerization process depends on the substrate conductivity and it increases with increasing the substrate conductivity. The optical absorption spectra show a major peak at similar to 800 nm corresponding to emeraldine salt (ES) phase of POMA irrespective of the substrate conductivity, However, the systematic increase in the overall absorbance and the sharpness of the peak at similar to 800 nm is observed with the increase in the substrate conductivity. The surface morphology of the POMA films also found to be depend on the substrate conductivity. (C) 2001 Elsevier Science BN. All rights reserved.