In-situ monitoring of microrheology on electrochemical deposition using an advanced quartz crystal analyzer and its application to polypyrrole deposition

Abstract

This paper introduces a technique for studying the microrheology of a thin film on a quartz crystal by considering the contrast of the resonant frequency change and resonant resistance change of the quartz crystal. An advanced measuring system was developed for the in-situ measurement of the resonant resistance on the electrochemical reaction. The system was used to monitor polypyrrole deposition by cyclic voltammetry and the constant current method. In the electrochemical deposition, not only the resonant frequency change but also the resonant resistance increase was observed, i.e. the deposited film was a viscoelastic film. The resonant resistance was changed in the range of 100–600 Ω for the resonant frequency change of 10 000 Hz; it showed a small change in the early stage of film deposition which increased after a resonant frequency change of 5000 Hz. The swelling of the film was observed corresponding to the unusual resonant resistance increase for the constant current deposition of 6 mA cm −2.