Interface aspects

Inoue, T. and Marechal, P. (1997) Reactive processing of polymer blends polymer-polymer interface aspects, in Processing of Polymers, ed. Meijer, H.F..H. Materials. Science and Technology, A Comprehensive Treatment, eds. Cahn, R.W., Haasen, P. and Kramer, E.J. (VCH, Weinheim) p. 429. 

Temporal Aspects Fundamental Interface Aspects Environmental Aspects... 

T. Imone and P. Marechal, Reactive processing of polymer blends polymer-polymer interface aspects, from Processing of Polymers, Vol. 18, H. E. H. Meijer (ed.), in Reprint from Materials Science and Technology, R. W. Cahn, P. Haasen, and E. J. Kramer (eds.), VCH Verlagsgesellschaft mbH, Weinheim, 1997, Chapter 8. 

Design properties. Covering aspects related to redundancy, diversity and functionality of the specific equipment (see example in Table 3). Special considerations. Aspects related to previous experience with/maturity of the equipment, complexity of the design, possible weak points in the design, etc. Human machine interface. Aspects related to accessibility to and maintainability of the equipment, including planned level of human interaction in... 

Systems involving an interface are often metastable, that is, essentially in equilibrium in some aspects although in principle evolving slowly to a final state of global equilibrium. The solid-vapor interface is a good example of this. We can have adsorption equilibrium and calculate various thermodynamic quantities for the adsorption process yet the particles of a solid are unstable toward a drift to the final equilibrium condition of a single, perfect crystal. Much of Chapters IX and XVII are thus thermodynamic in content. 

The solid-gas interface and the important topics of physical adsorption, chemisorption, and catalysis are addressed in Chapters XVI-XVIII. These subjects marry fundamental molecular studies with problems of great practical importance. Again the emphasis is on the basic aspects of the problems and those areas where modeling complements experiment. 

There is one remaining and very significant aspect of liquid-air and liquid-liquid interfaces to be considered before proceeding to a discussion of... 

The succeeding material is broadly organized according to the types of experimental quantities measured because much of the literature is so grouped. In the next chapter spread monolayers are discussed, and in later chapters the topics of adsorption from solution and of gas adsorption are considered. Irrespective of the experimental compartmentation, the conclusions as to the nature of mobile adsorbed films, that is, their structure and equations of state, will tend to be of a general validity. Thus, only a limited discussion of Gibbs monolayers has been given here, and none of such related aspects as the contact potentials of solutions or of adsorption at liquid-liquid interfaces, as it is more efficient to treat these topics later. 

The discussion focuses on two broad aspects of electrical phenomena at interfaces in the first we determine the consequences of the presence of electrical charges at an interface with an electrolyte solution, and in the second we explore the nature of the potential occurring at phase boundaries. Even within these areas, frequent reference will be made to various specialized treatises dealing with such subjects rather than attempting to cover the general literature. One important application, namely, to the treatment of long-range forces between surfaces, is developed in the next chapter. 

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. 

Ruch and Bartell [84], studying the aqueous decylamine-platinum system, combined direct estimates of the adsorption at the platinum-solution interface with contact angle data and the Young equation to determine a solid-vapor interfacial energy change of up to 40 ergs/cm due to decylamine adsorption. Healy (85) discusses an adsorption model for the contact angle in surfactant solutions and these aspects are discussed further in Ref. 86. 

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. 

Again with platinized Ti02, ultraviolet irradiation can lead to oxidation of aqueous CN [323] and to the water-gas shift reaction, CO + H2O = H2 + CO2 [324]. Some mechanistic aspects of the photooxidation of water (to O2) at the Ti02-aqueous interface are discussed by Bocarsly et al. [325]. 

Some features of late-stage interface dynamics are understood for model B and also for model A. We now proceed to discuss essential aspects of tiiis interface dynamics. Consider tlie Langevin equations without noise. Equation (A3.3.57) can be written in a more general fonn ... 

Using friction attaclnnents (see section (bl.20.2.4)). many remarkable discoveries related to tiiin-film and boundary lubrication have been made with the SEA. The dynamic aspect of confined molecules at a sliding interface has been extensively investigated and the SFA had laid the foundation for molecular tribology long before the AFM teclnhque was available. 

Most characteristics of amphiphilic systems are associated with the alteration of the interfacial stnicture by the amphiphile. Addition of amphiphiles might reduce the free-energy costs by a dramatic factor (up to 10 dyn cm in the oil/water/amphiphile mixture). Adding amphiphiles to a solution or a mixture often leads to the fomiation of a microenuilsion or spatially ordered phases. In many aspects these systems can be conceived as an assembly of internal interfaces. The interfaces might separate oil and water in a ternary mixture or they might be amphiphilic bilayers in... 

A very important aspect of both these methods is the means to obtain radial distribution functions. Radial distribution functions are the best description of liquid structure at the molecular level. This is because they reflect the statistical nature of liquids. Radial distribution functions also provide the interface between these simulations and statistical mechanics. 

Economic Aspects. Costs for gc/k/ms instmments vary widely depending on the sophistication of the components. At the lower end of the scale is the flow cell type gc/ftks connected to a benchtop mass spectrometer. These are available for about 115,000—150,000. The isolation type gc/fdr can also be interfaced with a benchtop mass spectrometer. The prices range from about 200,000—300,000. 

Economic Aspects. The Ic interface to a mass spectrometer is usually provided as an option to the more sophisticated, full capabiHty instmments. Some systems can have both Ic and gc interfaces and can conveniently switch between the two modes. Lc interfaces are approximately 30,000 bringing a Ic/ms that includes a data system into the 130,000—180,000 range. 

One approach to interfacing with such devices is serial interfaces. This involves two aspects ... 

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