Subject surface chemistry

In recent years, advances in experimental capabilities have fueled a great deal of activity in the study of the electrified solid-liquid interface. This has been the subject of a recent workshop and review article [145] discussing structural characterization, interfacial dynamics and electrode materials. The field of surface chemistry has also received significant attention due to many surface-sensitive means to interrogate the molecular processes occurring at the electrode surface. Reviews by Hubbard [146, 147] and others [148] detail the progress. In this and the following section, we present only a brief summary of selected aspects of this field. 

Dislocation theory as a portion of the subject of solid-state physics is somewhat beyond the scope of this book, but it is desirable to examine the subject briefly in terms of its implications in surface chemistry. Perhaps the most elementary type of defect is that of an extra or interstitial atom—Frenkel defect [110]—or a missing atom or vacancy—Schottky defect [111]. Such point defects play an important role in the treatment of diffusion and electrical conductivities in solids and the solubility of a salt in the host lattice of another or different valence type [112]. Point defects have a thermodynamic basis for their existence in terms of the energy and entropy of their formation, the situation is similar to the formation of isolated holes and erratic atoms on a surface. Dislocations, on the other hand, may be viewed as an organized concentration of point defects they are lattice defects and play an important role in the mechanism of the plastic deformation of solids. Lattice defects or dislocations are not thermodynamic in the sense of the point defects their formation is intimately connected with the mechanism of nucleation and crystal growth (see Section IX-4), and they constitute an important source of surface imperfection. 

This chapter and the two that follow are introduced at this time to illustrate some of the many extensive areas in which there are important applications of surface chemistry. Friction and lubrication as topics properly deserve mention in a textbook on surface chemistiy, partly because these subjects do involve surfaces directly and partly because many aspects of lubrication depend on the properties of surface films. The subject of adhesion is treated briefly in this chapter mainly because it, too, depends greatly on the behavior of surface films at a solid interface and also because friction and adhesion have some interrelations. Studies of the interaction between two solid surfaces, with or without an intervening liquid phase, have been stimulated in recent years by the development of equipment capable of the direct measurement of the forces between macroscopic bodies. 

This chapter concludes our discussion of applications of surface chemistry with the possible exception of some of the materials on heterogeneous catalysis in Chapter XVIII. The subjects touched on here are a continuation of Chapter IV on surface films on liquid substrates. There has been an explosion of research in this subject area, and, again, we are limited to providing just an overview of the more fundamental topics. 

Spectroscopy is basically an experimental subject and is concerned with the absorption, emission or scattering of electromagnetic radiation by atoms or molecules. As we shall see in Chapter 3, electromagnetic radiation covers a wide wavelength range, from radio waves to y-rays, and the atoms or molecules may be in the gas, liquid or solid phase or, of great importance in surface chemistry, adsorbed on a solid surface. 

Adsorption phenomena from solutions onto sohd surfaces have been one of the important subjects in colloid and surface chemistry. Sophisticated application of adsorption has been demonstrated recently in the formation of self-assembhng monolayers and multilayers on various substrates [4,7], However, only a limited number of researchers have been devoted to the study of adsorption in binary hquid systems. The adsorption isotherm and colloidal stabihty measmement have been the main tools for these studies. The molecular level of characterization is needed to elucidate the phenomenon. We have employed the combination of smface forces measmement and Fomier transform infrared spectroscopy in attenuated total reflection (FTIR-ATR) to study the preferential (selective) adsorption of alcohol (methanol, ethanol, and propanol) onto glass surfaces from their binary mixtures with cyclohexane. Om studies have demonstrated the cluster formation of alcohol adsorbed on the surfaces and the long-range attraction associated with such adsorption. We may call these clusters macroclusters, because the thickness of the adsorbed alcohol layer is about 15 mn, which is quite large compared to the size of the alcohol. The following describes the results for the ethanol-cycohexane mixtures [10],... 

Matthew Hyman and Will Medlin (University of Colorado) review the surface chemistry of electrode reactions, with the intent of introducing this subject to the non-electrochemists. They show the basics of both thermodynamic and kinetic analysis of these reactions, with examples that demonstrate these key principles. 

The aim of this review is to first provide an introduction of electrocatalysis with the hope that it may introduce the subject to non-electrochemists. The emphasis is therefore on the surface chemistry of electrode reactions and the physics of the electrode electrolyte interface. A brief background of the interface and the thermodynamic basis of electrode potential is presented first in Section 2, followed by an introduction to electrode kinetics in Section 3. This introductory material is by no means comprehensive, but will hopefully provide sufficient background for the rest of the review. For more comprehensive accounts, please see texts listed in the references.1-3... 

The fundamental physical chemistry of monolayers was worked out several decades ago by Langmuir, Harkins, Rideal, Adam, Schul-man, and others. In an excellent monograph, Gaines (38) has summarized the history and the state of knowledge up to 1966 of monolayers at air-liquid interfaces. Other good accounts of the subject can be found in several more general texts on surface chemistry (39-43). None, however, includes a discussion (or even a reference) to chirality in monolayers. 

Titanium dioxide occurs in three crystalline modifications anatase, rutile, and brookite. In all three forms, each Ti + ion is surrounded by six 0 ions and each ion has three Ti + neighbors. Both anatase and rutile are important white pigments which are produced on a large scale. Even though their surface chemistry is very important for their technological application, astonishingly little has been published in the chemical literature on this subject. However, it is very likely that many investigations have been undertaken in industrial laboratories. 

In this chapter, we will survey the kinds of solid supports (substrates) and surface chemistries currently used in the creation of nucleic acid and protein microarrays. Which are the best supports and methods of attachment for nucleic acids or proteins Does it make sense to use the same attachment chemistry or substrate format for these biomolecules In order to begin to understand these kinds of questions, it is important to briefly review how such biomolecules were attached in the past to other solid supports such as affinity chromatography media, membranes, and enzyme-linked immxm-osorbent assay (ELISA) microtiter plates. However, the microarray substrate does not share certain unique properties and metrics with its predecessors. Principal among these are printing, spot morphology, and image analysis they are the subjects of subsequent chapters. 

Since this book first appeared, there have been hundreds of neiv publications on the subject of iron oxides. These have covered a wide range of disciplines including surface chemistry, the geosciences, mineralogy, environmental science and various branches of technology. In view of the amount of new material that is available, we decided, that once the copies of the first edition were exhausted, we would prepare a second edition that would incorporate the new developments. 

The important point to recognize is that the etch rate of surfaces subjected to energetic particle bombardment (bottom surfaces) will be larger than the etch rate of surfaces not subjected to this bombardment (sidewalls) because of the ion-assisted (or electron-assisted) gas-surface chemistry. The relationship between the shape of an etched profile and the dependence of the etch rate on ion bombardment is shown in... 

The primary objective of this book is to bridge the gap between today s typical physical chemistry course and the literature of colloid and surface chemistry. The reader is assumed to have completed a course in physical chemistry, but no prior knowledge of the topics under consideration is assumed. The book is, therefore, introductory as far as the topic subjects are concerned, although familiarity with numerous other aspects of physical chemistry is required background. 

Since physical chemistry is the point of departure for this presentation, the undergraduate chemistry major is the model reader toward whom the book is addressed. This in no way implies that these are the only students who will study the material contained herein. Students majoring in engineering, biology, physics, materials science, and so on, at both the undergraduate and graduate levels will find aspects of this subject highly useful. The interdisciplinary nature of colloid and surface chemistry is another aspect of these subjects that contributes to their relevance in today s curricula. 

In the traditional surface science approach the surface chemistry and physics are examined in a UHV chamber at reactant pressures (and sometimes surface temperatures) that are normally far from the actual conditions of the process being investigated (catalysis, CVD, etching, etc.). This so-called pressure gap has been the subject of much discussion and debate for surface science studies of heterogeneous catalysis, and most of the critical issues are also relevant to the study of microelectronic systems. By going to lower pressures and temperatures, it is sometimes possible to isolate reaction intermediates and perform a stepwise study of a surface chemical mechanism. Reaction kinetics (particularly unimolecular kinetics) measured at low pressures often extrapolate very well to real-world conditions. 

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