CONDUCTIVITY RELAXATION OF 1-METHYL-2-PYRROLIDONE-PLASTICIZED POLYANILINE FILM

The conductivity relaxation of 1-methyl-2-pyrrolidone (NMP)-plasticize d polyaniline (PAn) film was measured using dielectric analysis (-50 t o +250 degrees C, 0.4-10(5) Hz). The complex electric modulus (M) rep resentation of the results of dielectric measurement of NMP-plasticize d PAn film exhibits two relaxation peaks, which is contrary to the sin gle relaxation. peak of the PAn powder (free from NMP). This implicate s a two-phase interwoven network structure of the film, which is suppo rted by the results from UV-vis spectroscopy (-50 to +250 degrees C) a nd near-field scanning optical microscopy of the NMP-plasticized PAn f ilm and from the conductivity relaxations of the model compounds: the fully oxidized and fully reduced forms of PAn powder. The peak at lowe r frequency is due to the conductivity relaxation of the phase with ox idized repeat units and that at higher frequency to the relaxation of the phase with reduced repeat units. The conductivity of the phase of reduced repeat units is higher than that of the phase of oxidized repe at units.