In this paper a comparative study of the structure, morphology, and the spectroelectrochemical response of poly (2-ethyl aniline) and polyaniline for different counterions is presented. Spongeous structure of poly (2-ethyl aniline) is obtained when mineral acids are used, while homogeneous and compact films are formed using organic acids. The electrochemical response of poly (2-ethyl aniline) depends on the charge/size ratio of the counterion due to both steric and electronic effects. The correlation between the absorption bands and the redox couple show that the changes in absorbance are proportional to the faradaic current observed in the voltammograms.
polyaniline; poly(2-ethylaniline); spectroelectrochemistry; DSC; SEM
