Electrochemical Quartz Crystal Microbalance Studies of Electroactive Surface Films

Abstract

Quartz is a particularly useful piezoelectric material. It can be produced economically, is stable, and is chemically inert. In the electrochemical quartz crystal microbalance (EQCM) technique, the exciting electrode on the crystal face contacting the solution also serves as the working electrode in an electrochemical cell while simultaneous mass and electrochemical responses are obtained. Not all electrode materials of interest adhere strongly to quartz under electrochemical solution conditions. The EQCM can be used to determine the overall population changes for all the mobile species transferring upon switching of an electroactive Surface film. The EQCM may also be employed in conjunction with in situ optical or spectroscopic techniques, as exemplified by a combined EQCM-ellipsometric study of polyaniline. The EQCM has been used to monitor the electrochemically induced deposition of a variety of materials. The EQCM has also been applied to study a variety of adsorption phenomena and to characterize the resultant films.