Importance of Surfaces and Interfaces

Starting with basic physical concepts and synthetic techniques, the book describes how molecules assemble into highly ordered structures as single crystals and thin films, with examples of characterization, morphology and properties. Special emphasis is placed on the importance of surfaces and interfaces. The final chapter gives a personal view on future possibilities in the field. 

As we have discussed earlier in the context of surfaces and interfaces, the breaking of the inversion synnnetry strongly alters the SFIG from a centrosynnnetric medium. Surfaces and interfaces are not the only means of breaking the inversion synnnetry of a centrosynnnetric material. Another important perturbation is diat induced by (static) electric fields. Such electric fields may be applied externally or may arise internally from a depletion layer at the interface of a semiconductor or from a double-charge layer at the interface of a liquid. 

MEIS has proven to be a powerful and intuitive tool for the study of the composition and geometrical structure of surfaces and interfaces several layers below a surface. The fact that the technique is truly quantitative is all but unique in surface science. The use of very high resolution depth profiling, made possible by the high-resolution energy detectors in MEIS, will find increased applicability in many areas of materials science. With continued technical development, resulting in less costly instrumentation, the technique should become of even wider importance in the years to come. 

The aspect of sample preparation and characterization is usually hidden in the smallprint of articles and many details are often not mentioned at all. It is, however, a very crucial point, especially with surface and interface investigations since there might be many unknown parameters with respect to surface contaminations, surface conformations, built-in stresses, lateral sample inhomogeneities, roughness, interfacial contact etc. This is in particular important when surfaces and interfaces are investigated on a molecular scale where those effects may be quite pronounced. Thus special care has to be taken to prepare well defined and artifact free specimens, which is of course not always simple to check. Many of these points are areas of... 

Classical surface and colloid chemistry generally treats systems experimentally in a statistical fashion, with phenomenological theories that are applicable only to building simplified microstructural models. In recent years scientists have learned not only to observe individual atoms or molecules but also to manipulate them with subangstrom precision. The characterization of surfaces and interfaces on nanoscopic and mesoscopic length scales is important both for a basic understanding of colloidal phenomena and for the creation and mastery of a multitude of industrial applications. 

Electrochemical processes usually take place on rough surfaces and interfaces and the use of fractal theory to describe and characterize the geometric characteristics of surfaces and interfaces can be of significant importance in electrochemical process description and optimization. Drs. Joo-Young Go and... 

This chapter describes the self-assembly of non-native protein fibers known as amyloid fibrils and the development of these fibrils for potential applications in nanotechnology and biomedicine. It extends an earlier review by the author on a related topic (Gras, 2007). In Section 1, the self-assembly of polypeptides into amyloid fibrils and efforts to control assembly and any subsequent disassembly are discussed. In Section 2, this review focuses on the important role of surfaces and interfaces during and after polypeptide assembly. It examines how different surfaces can influence fibril assembly, how surfaces can be used to direct self-assembly in order to create highly ordered structures, and how different techniques can be used to create aligned and patterned materials on surfaces following self-assembly. 

Capillarity — (a) as a branch of science, it concerns the thermodynamics of surfaces and - interfaces. It is of utmost importance for - electrochemistry, e.g., treating the electrode solution interface (- electrode, - solution), and it extends to several other branches of physics, chemistry, and technical sciences [i]. The thermodynamic theory of capillarity goes back to the work of Gibbs, (b) In a practical sense capillarity means the rise or fall of a liquid column in a capillary caused by the interplay of gravity and -> interfacial tension and also phenomena like capillary condensation [ii]. 

Some physical properties of semiconductor electrodes depend on the orientation of the crystal, and surface properties vary from one crystal plane to the other. It is therefore very important in studies of surface and interface effects that the proper surface is selected. A semiconductor crystal can be cut by sawing or by cleavage. Cleavage in... 

At the end of each chapter there is a review of the concepts introduced in that chapter and a set of problems making use of those concepts. The problems are of three types those that can be solved after careful reading of the chapter those denoted by one star, which refer the reader to important papers in the literature and problems denoted by two stars, which require an extended study of the subject. Solutions are provided for the first two classes of problems. This way the reader can explore important areas of surfaces and interfaces that are outside the scope of the book. 

The geometric structure and diemical composition of surfaces and interfaces is of fundamental importance for the initial growth of films... 

Micro- and nanostructured materials, often characterized by a significant amount of surfaces and interfaces, have been attracting intensive interest because of their demonstrated or anticipated unique properties compared to conventional materials. As an important type of carrier for foreign species, micro- and nanocontainers are common in namre, for example, the vesicles in living cells. A vesicle is a small, intracellular, membrane-enclosed container that stores or transports substances within a cell. 

The Reynolds number measures the relative importance of inertial terms to friction (viscosity) terms. It is defined by Re = (lvp)/rj, where is a typical length scale. When Re 1 one is describing a high viscosity flow (laminar flow). When Re I the inertial terms are dominant (potential flow). An ideal fluid has = 0 and only shows potential flow. Near walls, which are important for surface and interface problems, the velocity drops to zero so the important regime is that of low Re. 

The following is a summary, based on Ref. 1, of the types of molecular interactions that are important in understanding the structure and phase behavior of surfaces and interfaces. Because they are multicomponent, the interactions in systems with surfaces and interfaces are often related to the interactions between molecules in a particular type of medium. This is particularly important for self-assembling systems composed of surfactants or polymers, where the interactions and the subsequent equilibrium structures are strongly influenced by the type of solvent. 

In particular, statement (1) above underlines the importance of surface or interface chemistry for the whole process. The particle-water interface may be, on the one hand either charged or uncharged, and on the other hand, either smooth or rough (fibrous). How the particular look of the interface influences the overall polymerization kinetics was recently shown by means of calorimetric data (67). For instance, the greater A/ (stabilizer corona), then the more is the maximum in the polymerization time curves shifted towards longer times. The... 

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