Charge stabilisation

In studying the stability of colloidal dispersions it is of considerable advantage if the particles concerned are monodisperse and spherical. For aqueous, charge-stabilised systems polymer latices have proved invaluable in this regard. With non-aqueous systems, steric stabilisation is usually required. In this case it... 

AMP-95 is a non-polymeric charge stabiliser because of its organic structure and low molecular weight of 89 it is often referred to as a micro dispersant (Figure 1). 

Pursuing the idea that physical quenching efficiency and dealkylation might depend on mesomeric and anchimeric charge stabilisation, a series of phenothiazine derivatives is currently under investigation in order to determine rate constants of physical quenching and chemical reaction. 

Cyclopentadienium (cation), and aza-analogs, antiaromaticity, 56, 347 Cyclopenta(4]imidazole, topological charge stabilisation, 56, 348 2//-Cyclopenta[c]pyridazine, 2-methyl-, bromination, chlorination, 59, 302-3... 

That it is this group exclusively which migrates, may reflect vertical charge stabilisation by the donating effect of the Si-Si ff-electrons to the vacant p-orbitals of the silylcarbenes. 

The two main forms of charge stabilisation have already been introduced in the context of polarised bonds, i.e. the inductive and mesomeric effects. Other mechanisms exist, and these may be of overriding importance when they are... 

Charge stabilisation of the anion, which is formed after deprotonation, is still important, but to a lesser extent than when the acid/base reaction is reversible. If butyllithium is used as a base, then very unreactive hydrogens may be removed, which result in unstabilised anions. However, the conjugate acid is butane, which is a very, very weak acid also, as it is a gas, it leaves the reaction vessel. Thus, if butyllithium is used, the deprotonation becomes effectively irreversible. 

Charge-Stabilised Emulsions (e.g., Using Ionic Surfactants)... 

In the case of charge-stabilised dispersions above a certain concentration, addition of electrolyte often leads to gelation rather than the formation of distinct floes. Thus gelation may be regarded as the formation of an extended, continuous floe filling... 

The charge-stabilised latex had a ratio of 0.03 indicating essentially complete coagulation, whereas the methoxy PEG stabilized latex had a ratio of 0.60 indicating that a substantial proportion of the particles had remained in a colloidally stable form. 

Journal of Rheology 44, No.6, Nov./Dec.2000, p. 1279-92 VISCOSITY OF BIMODAL CHARGE-STABILISED POLYMER DISPERSIONS... 

In oil-containing aqueous effluents the oil is present as finely dispersed droplets in a relatively clean water phase, for example oilfield produced water, refinery process water, ballast water from cargo tankers [32]. Factors preventing coalescence include the droplet s negative electrostatic charge, stabilisation by surface active components and steric stability caused by fine solids. 

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