Sa. John et R. Ramaraj, ELECTROCHEMICAL, IN-SITU SPECTROCYCLIC VOLTAMMETRIC AND ELECTROCHROMIC STUDIES OF PHENOSAFRANINE IN NAFION((R)) FILM, Journal of electroanalytical chemistry [1992], 424(1-2), 1997, pp. 49-59
The standard Gibbs energy of hydrophobic interaction of phenosafranine
(PS+) dye with Nafion(R) film (Delta G(h)(o)) was estimated as - 21.1
7 +/- 0.04 kJ mol(-1). The positive and negative scans of PS + in Nafi
on(R) film showed markedly different electrochemical behavior. The app
arent diffusion coefficient D-app(red) calculated for the reduced PS(PSH2+) was higher than that of the PS+ (D-app(ox)) in Nafion(R) film,
explained by the greater interaction of PS+ with the hydrophobic regi
on of the Nafion(R) film than the PSH2+. Addition of 2-propanol to the
supporting electrolyte (0.5 M H2SO4) led to the release of PS+ from t
he electrochemically inactive to the electrochemically active regions
of the Nafion(R) film. In the in situ spectrocyclic voltammetry study
of PS+ in Nafion(R) film, the formation of leuco dye (PSH2+) was obser
ved during the reduction of PS+. The formation of monomer PS+ and dime
r (PS+)(2) was also observed in the in situ spectral study during the
oxidation of PSH2+ in Nafion(R) film aside from its electrochromic beh
avior.