RAMAN-SPECTROSCOPY FOR THE STUDY OF POLYANILINE

Raman spectroscopy (RS) is generally used for a qualitative discrimina tion of the different polyaniline (PANI) forms. The theoretical assign ment of the main bands nas done satisfactorily in the case of insulati ng forms, but it is not the same in the case of conductive forms. A ne w band at approximate to 1330 cm(-1) empirically observed during proto nation is assumed to correspond to tile stretching of C-N+. bonds. Thi s band, as well as the C=N stretching one must be modified in function of the polaron delocalization. The electropolymerization of PANI allo ws to form films with variable protonation and/or oxidation levels; th e corresponding modifications of the Raman spectra can be scrutinized to progress in the interpretation of these spectra, in order to use th is technique for a better analysis of conductive polymers.