Haesik Yang, Hochun Lee, and Juhyoun Kwak, "Electrogravimetric and Electrochemical Ac Response of Polypyrrole Films," Anal. Sci. & Tech., 8 (4), 663 - 668 (1995.12.__.)
Ion transport of a polypyrrole/chloride (PPy/Cl) film and a polypyrrole/poly(styrensulfonate) (PPy/PSS) film as a function of applied dc potential was investigated by employing electrogravimetric impedance technique and electrochemical impedance technique. The cation and anion contribution to the whole charge capacitance and the diffusion coefficients of action and anion in a PPy/PSS film were calculated by fitting the electrogravimetric impedance data with proposed model circuit. The diffusion coefficients of Na+ in a 1 M NaClO4 solution are over 1 order of magnitude larger than those of ClO4-, and ClO4- contribution to charge compensation decreases as dc potential lowers. The charge compensation of a PPy/Cl film in a 1 M CsCl solution is carried out largely by Cl- at 0.2 V vs. Ag/AgCl and by Cs+ as well as Cl- at -0.4 V.
Keywords : Polypyrrole, Electrogravimetric Impedance, Electrochemical Impedance, Ion Transport, Diffusion Coefficient