INFLUENCE OF DOPANT, PH AND POTENTIAL ON THE SPECTRAL CHANGES OF POLY(O-METHOXYANILINE) - RELATIONSHIP WITH THE REDOX PROCESSES

Poly(o-methoxyaniline) films doped with functionalized acids show high solubility in conventional organic solvents and a high optical contra st between the reduced and the oxidized forms. They are also more stab le towards thermal treatment than when they are doped with HCl. These characteristics make them suitable for use in electrochromic displays. The electrochromic behavior of this soluble derivative of polyaniline was investigated in detail by comparing the curves obtained by the di fferentiation of absorbance at fixed wavelengths with simultaneously o btained voltammograms. This analysis allows the chromophore species pr oducing color changes to be related to the redox processes taking plac e during the electrochemical cycling. Molar absorptivities were calcul ated and the effect of pH on the absorption spectra of the emeraldine form of the polymer is also reported. (C) 1997 Elsevier Science S.A.