Electrostatic separation INDEX

The values of K can be roughly estimated within the framework of a simplified model suggesting electrostatic interactions of oxidized donor (D+), and reduced acceptor (A ) of radii rD+ and rA. separated by the distance Rda with media of dielectric constant e0 and refraction index n ... 

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. 

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