PROPERTIES OF LIQUID-LIQUID INTERFACES ANALYZED BY LIGHT SCATTERING SPECTRA OF CAPILLARY WAVES

利用基于外差检测的光散射光谱技术测量了液体表面毛细管波的光谱。将所得光谱与流体力学理论进行了比较。比较了使用简单的洛伦兹函数和基于关联函数的傅里叶变换的更精确的公式所得到的最佳拟合参数的表面张力和粘度。由后一种理论确定的表面张力与文献数据吻合得很好。得到了不同液液界面的毛细管波谱，并根据流体力学理论确定了界面张力。这种方法具有非接触式测量界面张力的优点，适用于多种液-液界面。我们考察了氟代烷中氟原子的降落物，发现降落物的值随分子中氟原子的数量而有系统地变化。这表明，由于微观结构的形成，自由能在体液中比在表面形成得更多。在此基础上，用格子气体模型研究了分子在液体表面的取向，其中假定了取向的分子相互作用。计算了分子在表面附近的有序性，结果表明，取向相互作用对表面张力或表面自由能有贡献。从界面光化学的角度，我们研究了固-液界面的激光烧蚀。结果表明，在界面处产生的烧蚀羽流具有高温高压特性，有可能应用于新的材料合成工艺。

Spectra of the capillary waves at liquid surfaces were measured by light scattering spectroscopy based on the heterodyne detection. The resultant spectra were compared with hydrodynamic theories. The surface tension and viscosity obtained as best-fit parameters by using a simple Lorentzian function and by a more accurate formulation based on the Fourier transform of the correlation function were compared. The surface tension determined by the latter theory agreed very well with the literature data. We obtained the capillary wave spectra for various liquid-liquid liquid interfaces, and the interfacial tension was determined by fitting to the hydrodynamic theory. The method has the advantage of non-contact measurement of the interfacial tension and is applicable to a wide variety of liquid-liquid interfacesWe examined the parachor assigned to fluorine atoms in fluorinated alkanes, and found that the value varies systematically with the number of fluorine atoms in the molecule. This suggests the lowering of the free energy by microscopic structure formation more in the bulk liquid than at the surface. Furthermore, molecular orientation at a liquid surface was studied by a lattice gas model, in which an orientational molecular interaction was assumed. The ordering of molecules near the surface is calculated, and it was shown that the orientational interaction can contribute to the surface tension, or the surface free energy.From a point of view of photochemistry at interfaces, we investigated laser ablation at solid-liquid interfaces. It was found that the ablation plume produced at the interface shows high temperature and high pressure, which has a potential to be applied to a new process for material synthesis.