Sauerbrey equation

About: Sauerbrey equation is a research topic. Over the lifetime, 190 publications have been published within this topic receiving 21519 citations.

Viscoelastic Acoustic Response of Layered Polymer Films at Fluid-Solid Interfaces: Continuum Mechanics Approach

Abstract: We have derived the general solution of a wave equation describing the dynamics of two-layer viscoelastic polymer materials of arbitrary thickness deposited on solid (quartz) surfaces in a fluid environment. Within the Voight model of viscoelastic element, we calculate the acoustic response of the system to an applied shear stress, i.e. we find the shift of the quartz generator resonance frequency and of the dissipation factor, and show that it strongly depends on the viscous loading of the adsorbed layers and on the shear storage and loss moduli of the overlayers. These results can readily be applied to quartz crystal acoustical measurements of the viscoelasticity of polymers which conserve their shape under the shear deformations and do not flow, and layered structures such as protein films adsorbed from solution onto the surface of self-assembled monolayers.

Measurement of interfacial processes at electrode surfaces with the electrochemical quartz crystal microbalance

Abstract: I. Introductlon The last 10-15 years have seen electrochemista applying more and more sophisticated instrumental techniques to studies of electrode surfaces, both because of the increased availability of powerful new tools for interfacial characterization and because of an increased emphasis in modern electrochemical research on detailed characterization of the structure and composition of the interface. Many methods have been newly applied to the study of electrochemical interfaces' during this time. One of these methods is based on quartz crystal microbalance (QCM) technology. The

Quartz crystal microbalance setup for frequency and Q‐factor measurements in gaseous and liquid environments

Abstract: An experimental setup has been constructed for simultaneous measurements of the frequency, the absolute Q factor, and the amplitude of oscillation of a quartz crystal microbalance (QCM). The technical solution allows operation in vacuum, air, or liquid. The crystal is driven at its resonant frequency by an oscillator that can be intermittently disconnected causing the crystal oscillation amplitude to decay exponentially. From the recorded decay curve the absolute Q factor (calculated from the decay time constant), the frequency of the freely oscillating crystal, and the amplitude of oscillation are obtained. All measurements are fully automated. One electrode of the QCM in our setup was connected to true ground which makes possible simultaneous electrochemistry. The performance is illustrated by experiments in fluids of varying viscosity (gas and liquid) and by proteinadsorptionin situ. We found, in addition to the above results, that the amplitude of oscillation is not always directly proportional to the Q factor, as the commonly used theory states. This puts limitations on the customary use of the amplitude of oscillation as a measure of the Q factor.