Growth chemistry-controlled

The kinetics of crystal growth has been much studied Refs. 98-102 are representative. Often there is a time lag before crystallization starts, whose parametric dependence may be indicative of the nucleation mechanism. The crystal growth that follows may be controlled by diffusion or by surface or solution chemistry (see also Section XVI-2C). 

Environmental Considerations. Environmental problems in Ziegler chemistry alcohol processes are not severe. A small quantity of aluminum alkyl wastes is usually produced and represents the most significant disposal problem. It can be handled by controlled hydrolysis and separate disposal of the aqueous and organic streams. Organic by-products produced in chain growth and hydrolysis can be cleanly burned. Wastewater streams must be monitored for dissolved carbon, such as short-chain alcohols, and treated conventionally when necessary. 

Perhaps the best examples to illustrate the analysis strength of XPD and AED are the epitaxial growth modes of deposited overlayers. Here, the structure and chemistry of an overlayer, or the new interface, will influence the properties of the film. To control such effects, an understanding of the basic structure and chemistry is essential. Epitaxial Cu on Ni (001) is an excellent example for demonstrating the... 

Purely physical laws mainly control the behaviour of very large particles. Further down the particle size range, however, specific surface area, i.e. surface area per unit mass, increases rapidly. Chemical effects then become important, as in the nucleation and growth of crystals. Thus, a study of particulate systems within this size range of interest has become very much within the ambit of chemical engineering, physical chemistry and materials science. 

The syntheses described in the preceding section can be performed using as stabilizers the classical ligands of organometalhc chemistry (e.g., amines, thiols, or phosphines) instead of polymers. The amount of ligand added allows control of the particle growth and therefore the size. 

There is a large number of concepts and quantities of this kind used in actual investigations, and a large rate of increase of new formulations. This abundance of interpretative tools could lead somebody to suspect that we have lost any control on the growth and on the use of of these instruments and that interpretation in chemistry is becoming an exercise in which is possible to reach the conclusions one desires by an appropriate selection of the tools. 

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