Electrostatic phenomena

The model adopted by Ri and Eyring is not now acceptable, but some of the more recent treatments of electrostatic effects are quite close to their method in principle. In dealing with polar substituents some authors have concentrated on the interaction of the substituent with the electrophile whilst others have considered the interaction of the substituent with the charge on the ring in the transition state. An example of the latter method was mentioned above ( 7.2.1), and both will be encountered later ( 9.1.2). They are really attempts to explain the nature of the inductive effect, and an important question which they raise is that of the relative importance of localisation and electrostatic phenomena in determining orientation and state of activation in electrophilic substitutions. 

E. J. Rizzo, Electrostatic Phenomena in Textiles and Clothing Systems, U.S. Army Natick Laboratories, Natick, Mass., Oct. 1973. 

C. E. Lapple, Electrostatic Phenomena with Particulates J. R. Kittrell, Mathematical Modeling of Chemical Reactions... 

Because of the unavoidable tendency of granular solids to become triboelectrically charged when handled, it is no surprise that electrostatic phenomena are often quite pronounced in fluidized and spouted beds. The vigorous motion of fluidized particles—with constant particle-particle and particle-wall contacts—guarantees that electrical charging will take place. Electrostatic adhesion and cohesion, observed and recorded in the very earliest experimental investigations of fluidization, were immediately identified as experimental nuisances to be overcome. Somewhat later, the hazardous nature of electrostatics came to be appreciated. 

One point of particular interest is that it is not clear from the electrostatics-only models whether non-electrostatic phenomena affect the aqueous tautomeric equilibria. For instance, the DO results of Wong et al. [297] would suggest there are differentiating non-electrostatic phenomena, while the results of Young et al. [195] for a multipole expansion in a spherical cavity suggest that there are not. Since the SMI, SM2, and SM3 GB/ST models use Mulliken charges rather than... 

In the past, many of the electrostatic phenomena have been treated as unavoidable nuisances, and many processing problems have been blamed rather casually on electrostatic influences. Only in recent years has the scope of the role of electrostatics and its potential for application in processing begun to be more fully understood. 

It is the purpose of this chapter to summarize knowledge dealing with the role of electrostatic phenomena in particulate systems, especially in aerosols. A relatively comprehensive annotated bibliography by Blake and Lapple (BIO) has surveyed the bulk of the literature through 1965. This chapter cites and summarizes the results of the more important or directly relevant work in this field.1 However, before considering specific phenomena, it is desirable to review some of the fundamental principles in the field of electrostatics. 

Electrostatic phenomena are a function of particle properties as well as particle charge. Of particle properties, the one most important and subject to the widest variation is particle size.3 Consequently, it would be most con-... 

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