Data correction technique for using common electrochemical apparatus for the measurement of crystal impedance

Abstract

Crystal impedance (CI) is a well-known technique which extends the capabilities of the quartz crystal microbalance (QCMB) technique by refining the apparent mass change reported by QCMB resonance frequency measurements into a corrected mass change and an energy loss or dissipation component. In addition to mass change, the energy loss component can provide information about additional sample properties, such as surface rigidity or roughness, as well as the viscoeleastic properties of the medium in which measurements are performed. Previous reports of CI measurements involve the use of a network analyzer, an instrument not commonly found in an electrochemical research group. Here, we describe how to utilize a more common electrochemical impedance spectroscopy (EIS) system with sufficient bandwidth for the purpose of collecting CI data. Specifically, we discuss the measurement setup required to minimize impedance mismatch and a means of mathematically correcting for the impedance of the measurement system itself. We demonstrate the utility of this system using the CI response of a Pt-coated crystal to D-fructose solutions with known density and viscosity.