Dm. Soares, A QUARTZ MICROBALANCE WITH THE CAPABILITY OF VISCOELASTICITY MEASUREMENTS FOR INSITU ELECTROCHEMICAL INVESTIGATIONS, Measurement science & technology, 4(5), 1993, pp. 549-553
The frequency change of an electrochemical quartz crystal microbalance
(EQMB) is a function of both the rigid and the viscous masses coupled
to its surface. The viscoelastic properties of the contacting medium
define the mechanical loss of the vibrating quartz, which is character
ized by the resistance R' in the equivalent electrical circuit. In thi
s work a new driver circuit for the EQMB is described. It permits moni
toring of in situ changes of the resonant frequency f(s) and of the qu
artz crystal equivalent resistance R'. Thus this set-up allows one to
distinguish between the rigid and viscous masses. Results obtained in
different media with a prototype are discussed.