Adhesion of nylon particles to a quartz plate in an aqueous solution and their removal by electro-osmosis

Abstract

Particle removal by electro-osmotic flow was investigated by comparison with the removal by ordinary flow of water without electrokmetic effect. The relationship between adhesion and removal of particles in terms of force acting on the particle was also discussed. Experiments were carried out in an aqueous solution using nylon particles and a quartz plate. The adhesive force,F′T, for the particles which adhered to the quartz plate in secondary minima in the total potential energy of interaction versus separation distance curves was calculated. Particle removal experiments were carried out applying electro-osmotic and Poiseuille flows. The hydrodynamic force,Fd, which was required to remove particles from the plate was estimated using flow velocities. The effectiveness of electro-osmotic flow on particle removal was larger than that of Poiseuille flow. In the particle removal by electro-osmotic flow, the minimum of the ratioFd/F′t for particle removal was found to be 50 and the ratio for removal efficiency of 0.5 was about 140.