CHARACTERIZATION OF CHEMICALLY AND ELECTROCHEMICALLY PREPARED POLYANILINES IN INVERSE MICROEMULSIONS

Chemical polymerization of aniline in an inverse water-in-oil microemu lsion medium has been performed and the resulting ultrafine polymer pa rticles (10-35 nm) are spherical. The stoichiometries, thermal stabili ties and conductivities of polyanilines prepared in both microemulsion and aqueous media are generally similar. The presence of surfactant w as detected in the pre-washed polymer and it has a detrimental effect on the conductivity of the product. Considering the homogeneity of the product obtained in chemical microemulsion polymerization, the method has been applied to electropolymerization. The microemulsion method p rovided a denser, more uniform and compact film of higher conductivity than that produced in an aqueous medium. Apart from the doping level determined by XPS, the morphological differences. between the films pr oduced by the two polymerization media are responsible for the much hi gher conductivities measured for the films prepared in a microemulsion . A nucleation-initiated growth mechanism has been proposed to explain the results obtained.