New frequency/voltage converters for ac-electrogravimetric measurements based on fast QCM
Résumé
A better understanding of the mechanisms located at the solid/electrolyte interface is becoming
essential to the development of new applications in the electrochemical fields. The fast quartz crystal
microbalance is an attractive and powerful gravimetric sensor which can be used in the dynamic
regime to determine a mass/potential transfer function. The principle is equivalent to classical
electrochemical impedance measurements; the only difference is the determination of mass changes
given by the quartz crystal microbalance rather than current changes following sine wave
modulations of the applied potential. This function appears very well adapted to characterize ionic
exchanges at the electrochemical interface. Frequency/voltage converters are the key devices in
translating the microbalance frequency response in terms of a continuous voltage change. The latter
allows the transfer function to be obtained via a frequency response analyzer. Different converters
were tested in this work in order to improve the performances of the experimental setup.