Poly(m-chloroaniline): electrochemical synthesis and characterization

Abstract

The optical, morphological, thermal. and electrochemical properties of elcctrochemicaily synthesized poly(m-chloroaniline) reveal several unique features in comparison with similar well known properties of polyaniline. The nature and position of the halide substituent seem to be sensitive factor affecting the film properties. Optical spectra corresponding to different preparation conditions clearly display the significant role of pH during the formation of the conducting phase as gradual decrease in the ratio of absorbance at ∼850 nm to that of simultaneously produced other oxidation state species obtained by decreasing the protonation level. These results are supported by the IR analysis of the samples. The pintensity of quinoid to benzenoid ring modes [I₁₅₇₆/I₁₄₇₀] is highest at pH of -0.22, and decreases with increasing pH of solution. Intcrcstingly, with increasing pH from -0.22 to 3.3, the morphology of the films show a transition from fibrillar to granular type. The thermal patterns exhibit a positive shift in the final decomposition temperature. The influence of pH of solution on the redox properties of the films is seen in terms of change in shape and current magnitude of cyclic voltammograms.