Solid-liquid interface quartz

Slip is not always a purely dissipative process, and some energy can be stored at the solid-liquid interface. In the case that storage and dissipation at the interface are independent processes, a two-parameter slip model can be used. This can occur for a surface oscillating in the shear direction. Such a situation involves bulk-mode acoustic wave devices operating in liquid, which is where our interest in hydrodynamic couphng effects stems from. This type of sensor, an example of which is the transverse-shear mode acoustic wave device, the oft-quoted quartz crystal microbalance (QCM), measures changes in acoustic properties, such as resonant frequency and dissipation, in response to perturbations at the surface-liquid interface of the device. 

Thermal uniformity in the cold zone was found to be from 0.01 to 0.02 °C, and that in the hot zone was found to be better than + 0.5 °C vertically and + 0.1 °C horizontally. Thermal gradients near the solid-liquid interface were achieved in excess of 30 °C cm " in the crystal region and up to 20 °C cm" in the melt. The growth of crystals was performed in a sealed transparent silica ampoule, which has two rooms for As source and GaAs polycrystalline, respectively, separated by a quartz diffusion barrier. For details of the growth process the reader is referred to Ref. 43. In this experiment the As source temperature T. was systematically reduced by 2 °C at 3 h intervals from 620 °C to 614 °C. 

Meech and Yoshihara have used the surface second harmonic generation method to study ps dynamics at solid liquid interfaces by total internal reflection for the dyes, rhodamine and malachite green. The same technique has also been used to follow the photoreaction of rhodamine 6G in monolayers adsorbed on quartz . 

Probing the Solid/Liquid Interface with the Quartz Crystal Microbalance... 

Abstract In this chapter we discuss the results of theoretical and experimental studies of the structure and dynamics at solid-liquid interfaces employing the quartz crystal microbalance (QCM). Various models for the mechanical contact between the oscillating quartz crystal and the liquid are described, and theoretical predictions are compared with the experimental results. Special attention is paid to consideration of the influence of slippage and surface roughness on the QCM response at the solid-liquid interface. The main question, which we would like to answer in this chapter, is what information on... 

Similar strong orientation of molecules may occur at the solid-liquid interface as well, especially if the mutual solubility of the components is limited, i.e., both phases consist essentially of one component. According to the data presented by B.V. Derjaguin and N.B. Churaev, in some systems (for example, for water on quartz surface) the structured layers may have a thickness corresponding to several intermolecular distances. The formation of layers with the structure different from that present in the bulk of a phase is of importance for the stability of the disperse systems (see Chapter VII). Similarly to the interfaces between two liquids, the interfacial energy at the solid-liquid interfaces could, in principle, decrease with increasing temperature however such studies were not carried out due to difficulties in obtaining a at such interfaces. 

Michael Urbakh, Vladimir Tsionsl r, Eliezer Gileadi, Leonid Ddkhin Probing the Solid/Liquid Interface with the Quartz Crystal Microbalance. 

The relationship between adsorption and interfacial properties such as contact angle, zeta-potential and flotation recovery is illustrated in Figure 39.2 for cationic surfactant dodecylammonium acetate/quartz system (5). The increase in adsorption due to association of surfactants adsorbed at the solid-liquid interface into two dimensional aggregates called solloids (surface colloids) or hemi-micelles occurs at about 10 M DA A. This marked increase in adsorption density is accompanied by concomitant sharp changes in contact angle, zeta-potential and flotation recovery. Thus these interfacial phenomena depend primarily on the adsorption of the surfactant at the solid-liquid interface. The surface phenomena that reflect the conditions at the solid-liquid interface (adsorption density and zeta-potential) can in many cases be correlated directly with the phenomena that reflect the... 

The response of piezoelectric devices propagating shear horizontal acoustic plate modes (SH-APMs) has been modeled and experimentally characterized for variations in surface mass, liquid rheological properties, and solution dielectric coefficient and electrical conductivity. The nature of the SH-APM and its propagation characteristics are outlined and used to describe a range of Interactions at the solid/liquid interface. Sensitivity to sub-monolayer mass changes is demonstrated and a Cu sensor is described. The APM device is compared to the surface acoustic wave device and the quartz crystal microbalance for liquid sensing applications. 

Figure 11 SFG spectra of DOAC monolayer at the quartz-deuterated alkane interface. Each curve represents a specific tail length. (Reprinted from Thin Solid Films 161, P. B. Miranda, V. Pflumio, H. Saijo, Y. R. Shena, Surfactant monolayers at solid-liquid interfaces conformation and interaction, 327, 1998, with permission from Elsevier.)...

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