Colloids repulsion between hydrated

A number of refinements and applications are in the literature. Corrections may be made for discreteness of charge [36] or the excluded volume of the hydrated ions [19, 37]. The effects of surface roughness on the electrical double layer have been treated by several groups [38-41] by means of perturbative expansions and numerical analysis. Several geometries have been treated, including two eccentric spheres such as found in encapsulated proteins or drugs [42], and biconcave disks with elastic membranes to model red blood cells [43]. The double-layer repulsion between two spheres has been a topic of much attention due to its importance in colloidal stability. A new numeri-... 

Paunov, V.N., R.I. Dimova, P.A. Kralchevsky, G. Broze, and A. Mehreteab. 1996. The hydration repulsion between charged surfaces as an interplay of volume exclusion and dielectric saturation effects. J. Colloid Interface Sci. 182 239—248. 

Pashley, R. M., DLVO and hydration forces between mica surfaces in Li, Na, K, and Cs electrolyte solutions Correlation of double-layer and hydration forces with surface cation exchange properties, J. Colloid Interfac. Sci., 83, 531 (1981). Velamakanni, B. V., Chang, J. C., Lange, F. F., and Pearson, D. S., New method for efficient particle packing via modulation of repulsive lubricating hydration forces, Langmuir, 6(7), 1323 (1990). 

The stress defined by Equation (6) represents the interaction between surfaces due to the macromolecules in solution. To obtain the total stress, contrioutions of long range colloidal forces between the oilayers themselves must be added to (Tp. For phospholipid oilayers, the added stress can be expressed as the sum of a strong exponential repulsion due to hydration forces, a weak power law attraction for the van der Waals force, and exponential repulsion due to electric double layer forces (1-2),... 

The invention and refinement of the SFA have been among the most significant advances in experimental colloid science and have allowed researchers to identify and quantify most of the fundamental interactions occurring between surfaces in aqueous solutions as well as nonaqueous liquids. Attractive van der Waals and repulsive electrostatic double-layer forces, oscillatory (solvation or structural) forces, repulsive hydration forces, attractive hydrophobic... 

A pair of polysaccharide molecules approaching each other in water exerts an interaction potential ( ) that is the algebraic sum of the competing attractive and repulsive forces. integrated over all pairs of molecules, is . This principle is embodied in the Deijaguin-Verwey-Landau-Overbeek (DLVO) theory of colloidal stability (Ross and Morrison, 1988). The equilibrium distance between the molecules is related to c, the volume of the hydrated particles, ionic strength, cosolute, nonsolvent additions, temperature, and shearing. 

As already noted, the restabilization of some colloids at high ionic strength found in previous experiments20 can be explained in the traditional framework of the additivity between double layer and hydration forces, by a slight increase of the hydration repulsion caused by the increase in surface ion pair (dipole) density with electrolyte concentration. However, the increase in repulsion due to this mechanism is much too low to explain the strong increase of the second virial coefficient. 

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