INFLUENCE OF CONTACT ELECTRIFICATION ON THE COLLISION OF ELASTIC PARTICLES WITH A RIGID SURFACE

The influence of the contact formation of an electrical double layer ( EDL) on the collision of uncharged, perfectly elastic particles with a dry rigid surface is theoreticallY investigated. The kinetics of the formation of an EDL in the elastic collision of a particle, the work o f the nonequilibrium separation of the plates of the EDL when it rebou nds, and the magnitude of a charge gained by the particle on its colli sion are calculated. It is shown that the nonequilibrium forces associ ated with the EDL can considerably reduce the rebound velocity of part icles, in the case of their elastic collision, and even cause their st icking to the surface, when impinging against it at a velocity lower t han the critical one. The dependence of the critical collision velocit y on the geometrical, mechanical, and electrosurface parameters of par ticles and the substrate is established. Some known experimental data we well described by the expression for the rebound impingement veloci ty ratio, obtained from consideration of the energy balance. (C) 1987 Academic Press, Inc.