TRANSPORT-PROPERTIES OF SUBSTITUTED DERIVATIVES OF POLY(ANILINE)

Aromatic ring and N-substituted derivatives of poly(aniline) have been synthesized by chemical peroxodisulphate oxidation method in aqueous trichloroacetic acid. UV-visible spectra of these polymers show hypsoc hromic shift with increase in dielectric constant of the solvent and d ue to substitution in the aromatic ring. From temperature dependence o f electrical conductivity, charge localization length and hopping dist ance are calculated and the effect of substituent and dopant on crysta llinity is discussed. The introduction of substituent group either in a ring or at N-atoms produces space hinderance to internal rotation. T he bulky dopant may distort or destroy the lattice and reduce the crys tallinity. The temperature dependence of dielectric data and conductiv ity suggests that substituted derivatives of PANI are quasi 1D-disorde red state composed of 3D-metallic crystalline regions in 1D-localized amorphous regions.