Surface morphology and the quartz crystal microbalance response in liquids

The effect, of surface roughness and the morphology of non-uniform surface films, on a quartz crystal microbalance (QCM) response in contact with a liquid has been investigated. We used a perturbation theory for the description of the effect slight toughness and an approach based on Brinkman's equation for the case of Strong roughness the latter approach one treats the flow of a liquid through a nonuniform surface layer as the flow of a liquid through a porous medium. Our description includes both the effect of viscous dissipation in the interfacial layer and the effect of the liquid mass rigidly coupled to the surface. A relation between QCM response and the interface geometry has been found. The models discussed here can be used for the treatment of the QCM response of rough electrode surfaces, of porous deposited films and of surface polymer films.