Electrostatic structure

Hydrogen bonds are formed to some extent by oxygen ((H20)x, ice, etc.) and perhaps also in some cases by nitrogen. The electrostatic structure for the hydrogen bond explains the observation that only these atoms of high electron affinity form such bonds, a fact for which no explanation was given by the older conception. It is of interest that there is considerable... 

Nucleic acid stabilization, electrostatics, structure and potential stabilization or catalysis in enzymes... 

The theory is based on two observations. First, solute-solvent interactions are characterized by dipole-ion interactions, and so are much weaker than the ion-ion interactions between solvent species. Thus, the presence of the solute dipole should not greatly perturb the liquid from the electrostatic structure of the neat liquid. Second, because the ionic liquid is a conductor, the electric field of the solute must be screened by the solvent. This observation has been confirmed... 

Some of these categories of ions show distinctive structural and thermodynamic properties. The nonacidic metal cations and nonbasic anions are distinct from aU of the other categories, in that there is a positive entropy change accompanying their hydration as they dissolve from the solid state (Figure 2) they are known to physical chemists as electrostatic structure breakers because these large ions... 

There are a number of interaction forces, which can exist between particles—attractive van der Waals, repulsive electrostatic, structural and solvation forces, forces due to adsorbed and non-adsorbing polymer etc. These forces can be manipulated by a variety of different means—by adding salt to screen the charge on the particles, to index match the solvent and particles to screen van der Waals interactions and changing the solvency to affect the state of the adsorbed polymer to name a few. The chemical sensitivity of these interactions becomes particularly important when dealing with sub-100 nm particles or for situations where particles are held at separations on the order of a few nanometers. In both cases, the granularity of the continuous phase and chemical details of the interactions of the species in solution with the solid surface begin to dominate interactions. If conditions where the particles are held at small separations are of interest, these interactions must be characterized, as they cannot at present, be predicted. 

This chapter explores the number of mean field constructions for ions whose structure goes beyond the point charge description, the representation used in the standard Poisson-Boltzmann (PB) equation. The structural details omitted within a point charge picture can be related to electrostatic structure of an ion,... 

So far we have considered only interactions due to electrostatic structure of an ion. In addition to these there are also non-electrostatic interactions, generally short-ranged and repulsive, the most obvious of which are the excluded volume interactions due to the Pauli exclusion principle that prohibits two electrons from occupying the same quantum state [72]. 

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