Solid-liquid interface interfacial plane

The liquid-liquid interface is not only a boundary plane dividing two immiscible liquid phases, but also a nanoscaled, very thin liquid layer where properties such as cohesive energy, density, electrical potential, dielectric constant, and viscosity are drastically changed along with the axis from one phase to another. The interfacial region was anticipated to cause various specific chemical phenomena not found in bulk liquid phases. The chemical reactions at liquid-liquid interfaces have traditionally been less understood than those at liquid-solid or gas-liquid interfaces, much less than the bulk phases. These circumstances were mainly due to the lack of experimental methods which could measure the amount of adsorbed chemical species and the rate of chemical reaction at the interface [1,2]. Several experimental methods have recently been invented in the field of solvent extraction [3], which have made a significant breakthrough in the study of interfacial reactions. 

Jackson has proposed a simple lattice model for the interface, in which the points of an infinite lattice are identified as solidlike or liquidlike. A single interfacial plane (containing both types of atoms) is taken to separate the solid from the liquid. The problem with this model (and with its multilayer generalization by Temkin in Woodruff S) is that it gives a large negative entropic contribution to a so that for small values of the ratio AH/k T characteristic of most metals a becomes negative.We thus do not consider these models further here. 

Three interfaces come into play if a liquid drop is deposited on a solid surface, and three interfacial tensions are involved /sv, Xsi and respectively the solid-vapour, solid-liquid and liquid-vapour interfacial tensions. The mechanical equilibrium of the triple line fixes the value of the contact angle 0 at which the liquid-vapour interface meets the solid plane defined by Young s relationship (Figure 7.2) ... 

An interface is the region at the boundary between two immiscible phases. Ideally, the interfacial boundary is considered to be the plane dividing the phases. In real systems, the interface is not a plane but a region which has a composition different from that of the bulk phase (Fig. 4.1). The boundary may be solid-solid, solid-liquid, solid-vapor, liquid-liquid, or liquid-vapor immiscible phases. If one of the two phases in contact with each other is a gas or vapor, the term surface is used to denote the boundary. 

In what follows surface is defined as the plane between condensed matter and a vapour phase or vacuum, such as solid/vapour and liquid/vapour interfaces. In a broader sense, the term interface is used for the dividing plane between any two different phases. The existence of an interface means, by itself, the presence of an excess interface energy over the bulk energy. Since the driving force for sintering is the reduction of the total interfacial energy of the system concerned, it will be useful to understand the thermodynamic characteristics of interfacial energy. 

Colloid chemistry studies the nature and effects of surfaces and interfaces on the macroscopic properties of substances. These studies involve the investigation of Brownian motion/" surface tension, interfacial tension (the tension that exists in the plane of contact between a liquid and a solid, or between two liquids), wetting and spreading of Uquids on solids, adsorption of gases or of ions in solution on solid surfaces, etc. 

The experimental volume of liquid hydrogen has been simulated by a semiinfinite solid with the liquid—vapor interface representing a constant-temperature bounding face. Since equilibrium temperatures are observed throughout the test fluid prior to pressurization, and since the plane surface temperature immediately after pressurization is also known (saturation temperature corresponding to interfacial pressure), the uniform temperature of the liquid and the suddenly changed surface temperature are known. With this information, and certain physical fluid properties, the case of one-dimensional heat flow in a semiinfinite solid may be calculated. 

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