Quartz Crystal Microbalance Study: Ionic Motion Across Conducting Polymers

In situ monitoring of mass change was performed during electrochemical growth and redox cycling of a conducting polymer(polypyrrole) on a quartz crystal microbalance. For the polypyrrole films grown with large polymeric anions(poly(4‐styrenesulfonate) and polyvinylsulfonate), mostly cations and solvent molecules were inserted and removed to compensate charge in polypyrrole. The films formed with medium‐sized anions (tosylate) showed both apparent anion and cation motion during the redox process. The films prepared in the presence of small anions ( and ) showed mostly anion motion, but apparent cation motion also became significant for higher oxidation and/or reduction state.