Raman Spectroelectrochemistry of Polyaniline Synthesized Using Different Electrolytic Regimes – Multivariate Analysis

Potentiostatic, galvanostatic and cyclic potentiodynamic depositions of polyaniline were studied by cyclic voltammetry and in-situ Raman spectroscopy. Multivariate analysis of the spectroelectrochemical data including evolving factor analysis, multivariate curve resolution and 2Dcorrelation spectroscopy was applied to resolve overlapped bands in Raman spectra and to assign them reliably. Oxidized structures, related with a different chemical composition of the polymer chains, were evidenced in the leukoemeraldine ↔ emeraldine process with their proportions changing in the order: potentiostatic > galvanostatic > potentiodynamic. Both techniques, cyclic voltammetry and Raman spectroscopy indicate the most complex nature of the polymer films produced under the galvanostatic regime of electrolysis.