Solvation


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solvation

[säl′vā·shən]
(chemistry)
The process of swelling, gelling, or dissolving of a material by a solvent; for resins, the solvent can be a plasticizer.

Solvation

 

the association of molecules of a solvent with molecular, ionic, or particulate solute units. When the association involves water molecules, solvation is referred to as hydration.

Solvation results in the formation of solvates (hydrates), which are compounds of definite or, more often, indefinite composition. The molecules of the solvent are associated with the molecules or ions of the solvated substance through forces of various types and intensities, from weak forces of molecular interaction to the forces of chemical bonds. In solutions, the solvent molecules involved in solvation create spheres of solvation around the molecules or ions of solute.

A distinction is usually made between primary solvation, the interaction of molecules or ions of a substance with the closest molecules of solvent, and secondary solvation, the interaction of molecules or ions that have undergone primary solvation with more distant solvent molecules. When the solvation is complete, all the molecules of the solvent are associated with the spheres of solvation; that is, they enter the sphere of action of the force field of the molecules or ions of solute.

Solvation acts on the thermodynamic and other properties of the solution; it causes the electrolytic dissociation of electrolytes in polar solvents, the solubility of nonelectrolytes, and many liquid-phase chemical reactions. Solvation of molecules or ions of the surface layer is an extremely important factor in the stabilization of disperse systems having a high degree of dispersion in a liquid dispersion medium (sols, ladees, emulsions). Solvation may occur not only in a liquid solvent but also during the sorption by a substance of solvent vapors from a gaseous medium.

REFERENCES

Entelis, S. G., and R. P. Tiger. Kinetika reaktsii v zhidkoi faze. Moscow, 1973.
Matiash, I. V. Voda v kondensirovannykh sredakh. Kiev, 1971.
Kariakin, A. V., and G. A. Kriventsova. Sostoianie vody v organi-cheskikh i neorganicheskikh soedineniiakh.

L. A. SHITS

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This ranking of the normalized effect on conductivity according to polarity is in accord with the idea of solvation efficiency as described in the introduction.
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Universal solvation model based on solute electron density and on a continuum model of the solvent defined by the bulk dielectric constant and atomic surface tensions.
If an aqueous sample containing nucleic acids is mixed with suspended silica surfaces, and the solvation properties of the aqueous environment are disrupted (either by addition of alcohols, such as above, or by addition of chaotropic agents such as guanidine.
However, the performance of Coating A to reduce the contact/vapor hazards is limited to smaller CWA drop sizes, since absorption by solvation results in a localized build-up of agent that may saturate the coating.
This may affect important product characteristics such as translucence, tensile strength, and solvation.
The results of solvation shows that soluble in solvents such as methanol, water, slightly soluble in ethanol and dimethyl sulfoxide and insoluble in toluene, acetonitrile, chloroform and hexane.
In a PCM calculation, a solute molecule is placed in a cavity embedded in a continuum with a selected dielectric constant to approximately treat solvation effects.
1] is more accentuated and shifted at lower frequency in powder C characterized by a higher solvation extent.