Behavior of Ultra Fine Particles in Electric Field

The behavior of ultra fine particles in an electric field was measured in order to apply it to classification of fine particles. The sample particles used are spherical polystyrene particles with the average size of 0.03, 0.1, 1.0, 4.3 and 9.6 µm. The forces acting the particles in an electric field are considered to be electrical force, friction force and some other forces like the asymmetric effect and electrophoretic retardation effect which appear in ionic behavior. We found that the moving velocity of particles depends on the particle size. When the particle size is less than 1 µm, the velocity increases with increasing the particle size. On the other hand, the velocity deceases with an increase in the particle size, when the particle size is larger than 1 µm. We can apply the behavior to classification of fine particles. The phenomena could be explained by various forces acting the fine particles in the electric field.