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Chemical bridge theory

As shown in Fig. 7.7d polymers can destabilize colloids even if they are of equal charge as the colloids. In polymer adsorption (cf. Fig. 4.16) chemical adsorption interaction may outweigh electrostatic repulsion. Coagulation is then achieved by bridging of the polymers attached to the particles. LaMer and coworkers have developed a chemical bridging theory which proposes that the extended segments attached to one of the particles can interact with vacant sites on another colloidal particle. [Pg.258]

As pointed out earlier, a possible mechanism could be the chemical nature of the environment which is created after the application of CP in terms of increasing the local pH and inhibiting the bacterial reproduction of microbes [43] in such a high alkaline environment. But there are two seemingly rival theories in this respect, the electrostatic-chemical theory and the chemical bridge theory. We briefly explain these theories and interpretations below. [Pg.147]

An alternative theory that we call chemical bridge theory does not consider electrostatic forces of significant importance and rather relies on chemical binding, as will be discussed below. [Pg.149]

Mains et al. [49], in trying to explain why applying CP to stainless and structural steel surfaces immersed in seawater can inhibit the settlement and attachment of aerobic bacteria to these surfaces, call the use of electrostatic repulsion theory in explaining such phenomena as being an oversimplification . Instead, they propose an alternative mechanism. We call their proposed mechanism the chemical bridge theory, or CB. [Pg.149]

Improve adhesion of dissimilar materials such as polymers to inorganic substrates. Also called primers. Primers generally contain a multifunctional chemically reactive species capable of acting as a chemical bridge. In theory, any polar functional group in a compound may contribute to improved bonding to mineral surfaces. However, only a few organofunc-tional silanes have the balance of characteristics required... [Pg.773]

Initiated by the chemical dynamics simulations of Bunker [37,38] for the unimolecular decomposition of model triatomic molecules, computational chemistry has had an enormous impact on the development of unimolecular rate theory. Some of the calculations have been exploratory, in that potential energy functions have been used which do not represent a specific molecule or molecules, but instead describe general properties of a broad class of molecules. Such calculations have provided fundamental information concerning the unimolecular dissociation dynamics of molecules. The goal of other chemical dynamics simulations has been to accurately describe the unimolecular decomposition of specific molecules and make direct comparisons with experiment. The microscopic chemical dynamics obtained from these simulations is the detailed information required to formulate an accurate theory of unimolecular reaction rates. The role of computational chemistry in unimolecular kinetics was aptly described by Bunker [37] when he wrote The usual approach to chemical kinetic theory has been to base one s decisions on the relevance of various features of molecular motion upon the outcome of laboratory experiments. There is, however, no reason (other than the arduous calculations involved) why the bridge between experimental and theoretical reality might not equally well start on the opposite side of the gap. In this paper... results are reported of the simulation of the motion of large numbers of triatomic molecules by... [Pg.399]

At present, there are no generally accepted views on the formation of hard agglomerates of nanoparticles. There are several representative theories proposed, e.g., including crystal bridge theory, capillary pressure theory, hydrogen bond theory, chemical bond theory, etc. [21]. We shall only mention the essential concept of each theory. [Pg.706]

However, equations of state, too, will be an essential component of chemical engineering theory and practice for the foreseeable future, and as ever, the balance will need to be struck between rigorous theory and engineering applicability. One equation of state, which seems to have done an admirable job of bridging the gap between molecular theory and engineering application, is statistical associating fluid theory (SAFT) and it is with this equation of state and its spin-offs that the remainder of this discussion is concerned. [Pg.216]

A Bridge Between the Quantum Theory of Atoms in Molecules and Chemical Graph Theory... [Pg.53]

In its disciplinary development at the end of the nineteenth century, physical chemistry served as a bridge, not a wedge, between the mathematical abstractions of theoretical physics and the metaphorical descriptions of organic chemistry. Not only through novel theories but also through control of new instrumentation, much of it electrical and optical in nature, physical chemistry was to revitalize and transform techniques in the chemical laboratory and theories of chemical explanation. Notably for our concerns, speculations about reaction mechanisms in hydrocarbon chemistry were to begin to proliferate in the early 1900s. [Pg.156]

The gap between what we see and how we explain it today is bridged by a very elaborate and abstract invention. That our contemporary chemical theory is a powerful intellectual tool is obvious from the vast evidence of chemical success in our world today. Yet there is no apparent connection between this model and our direct experience of chemical change or of chemical properties. [Pg.2]


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See also in sourсe #XX -- [ Pg.149 ]




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