COMPARATIVE ELECTROCHEMISTRY OF PHENOTHIAZINE DYES INCORPORATED INTO NAFION AND POLY(STYRENESULFONATE) FILMS

The electrochemical properties of phenothiazine dyes, thionine (TH+) a nd methylene blue (MB+), incorporated into Nafion and PSS films were s tudied. These dyes showed different electrochemical behaviour in Nafio n film when compared to aqueous solution and PSS film. The observed el ectrochemical behaviour has been explained by the interaction of reduc ed TH+ and MB+ molecules with different regions of the Nafion film. In the PSS film, the incorporated dye molecules experienced purely a hyd rophilic environment and showed electrochemical properties similar to that of aqueous solution. Further, the interaction of the reduced MBmolecules with the hydrophobic fluorocarbon region of the Nafion film was studied by spectroelectrochemistry adding 2-propanol to the suppor ting electrolyte solution.