POLYANILINE - A MATERIAL STILL UNDER DISCUSSION

Several studies (13C NMR, vibrational spectroscopy, acidic titration, etc.) have been considered in this coherent description of the structure and the chemical composition of polymers of the polyaniline family. Among the different processes (oxidation, protonation, etc.) which relate the five polymers of this family, three are characterized by insulator-to-conductor transitions. The chemical aspects of these processes are explained in the framework of the preceding descriptions. Then, the variation of the magnetic and transport properties related to these transitions, as well as the models which have been proposed to account for these properties, are discussed. Special attention is paid to the problem of homogeneity of the material, after different types of doping. © 1990.