Spectroelectrochemical characterization (OMA and Raman) of sulfonic acids — doped polyanilines

Polyaniline films doped with camphorsulfonic acid (PANI-CSA) were prepared by electropolymerization and characterized by in situ Raman spectroscopy. Optical Multichannel Analysis (OMA) was used to characterize the changes of optical properties of PANI-CSA during the cycling in an electrochromic cell. The properties of PANI-CSA colored in 1 M HCSA were compared with those of PANI-CSA and PANI colored in 1M HCl. The striking fact is the increase of the polaron band (isolated polaron at 2.95 eV) during the coloration of PANI-CSA in HCSA. Secondary doping of these films after dissolution in m-cresol can be obtained.