Surfaces and Interfaces General Concepts

There are several types of interfaces that are of great practical importance and that will be discussed in turn. These general classifications include, solid-vacuum, liquid-vacuum, solid-gas, liquid-gas, solid-liquid, liquid-liquid, and solid-solid. From a practical standpoint, solid- and liquid-vacuum interfaces are of little concern. They are most often encountered in the context of theoretical derivations, since the absence of a second phase simplifies matters greatly, or in studies of high-vacuum processes such as deposition, and sputtering. The true two-phase systems (assuming that a vacuum is not considered to be a true phase ) are the ones which are of most importance in practical applications and that are addressed in most detail here. A list of commonly encountered examples of these interfaces is given in Table 2.1. 

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Myers, D. Surfaces and interfaces general concepts. In Surfaces, Interfaces, and Colloids Principles and Applications VCH Publishers Inc. New York, 1991 7-24. 

The purpose of this book is to describe the present state of development of modem surface science at an introductory level to students of physical sciences and engineering. Junior standing in chemistry, physics, engineering, or the life sciences would qualify the student to take a course that would make use of this text. Teachers of introductory general chemistry courses usually given during the first year of university or college enrollment could use certain chapters (with deletions of some of the derivations) to supplement discussions of thermodynamics or catalysis, for example. We have used some of the chapters as supplementary material in our freshman and our core physical chemistry courses at Berkeley. The book should also be useful as a reference for professionals in need of data and concepts related to the properties of surfaces and interfaces. 

General Observations About x. its Relationship to the Overall Partitioning Coefficient and to the Concept of Surface-Site Heterogeneity. One approach to metal/particle surface interactions which has been developed, historically, in a variety of forms, is a conceptual model that assumes only two conditions for surface sites occupied by an adsorbate or unoccupied. In applying this approach to the solid/aqueous solution interface, the adsorption... 

Sanfeld et al. (1990) have theoretically analysed the competition between chemical reactions at the surface and in the volume. They define a surface elasticity which is determined by the kinetics of all these processes and conclude that the effect of capillary forces may be considered as an external field acting on the reactive system. Their conception started from the principle of De Donder, as did our general description of relaxation in chemical reactions. To generalise relaxation phenomena at interfaces can be described as ordinary chemical reactions. In principle there is no distinction between the application of the laws to chemical kinetics in bulk phases and at interfaces. 

W.H. Weinberg. Precursor Intermediates and Precursor-Mediated Surface Reactions. General Concepts, Direct Observations and Indirect Manifestations. In M. Grunze and H.J. Kreuzer, editors. Workshop on Interface Phenomena, Springer Series in Surface Sciences, Volume 8. Springer-Verlag, New York, 1987. 

The surface properties of a phase generally differ from the bulk properties. Therefore the GC theory, which is based on macroscopic bulk concepts such as the dielectric constant, requires corrections. Indeed, this was the idea behind the mono-layer models discussed earher - their main fault was that they were too simple boundary layers extend beyond the first layer of molecules that is in contact with the metal. Furthermore, these models completely neglected the effect of the metal, which was treated as a perfect conductor without any electronic structure. In this section we will discuss a few models for the solution before we turn to the metal surface and then to the metal-solution interface. 

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