UNCONVENTIONAL METHODS FOR IWLUEN01NU FLUID FLOW Part IV High Field Electrophoresis of Solid Spherical Particles in Low Conductivity Liquids

摘要

The use of a high electric field in low conductivity liquids to obtain high electrophoretic velocity of suspended solid particles is proposed, and its mathematical theory based on the concept of an "electrokinetic double layer," which is formed at a solid-liquid interface, is examined.nThe mobility of a charged particle without the double layer is calculated. The retardation effect of the diffuse portion of the double layer is analyzed by considering the motion of a long thin cylindrical particle. The result is then extended to the case of a spherical particle to account for other retarda¬tion effects caused by the surface convection and conduction current. A closed form general equation for the mobility is obtained using the control volume concept to solve a modified Stokes problem. For low conductivity liquids, the general equation reduces to a simplified equation which is easy and still ac¬curate to use.nExperimental data for the mobility of Ag, Pb, Sn, In, Zn, Al and glass spheres of 100 micron radius suspended in transformer oil, and the mobility of glass and Indium spheres of different radii suspended in transformer oil and its solution with additives respectively are obtained. Experimental data for the electrophoretic motion of suspensions of plexiglass particles in flowing transformer oil are also reported.