Dynamic Electrophoretic Mobility of a Cylindrical Colloidal Particle
Accurate approximate formulas are obtained for the dynamic electrophoretic mobility of a cylindrical hard colloidal particle in an oscillating electric field for two cases where the cylinder is in a transverse field or in a tangential field. These formulas, expressed in terms of Hankel functions and modified Bessel functions, are suitable for numerical calculation for all kappaa (kappa is the Debye-Huckel parameter and a is the particle radius) at zero particle permittivity and low zeta potentials. The dynamic mobility in a tangential field is shown to depend on kappaa in contrast to the static case, where it is independent of kappaa. The dynamic mobility of a cylinder averaged over a random distribution of orientation of the cylinder axis is roughly equal to the mobility of a sphere with a radius of 1.5 times the cylinder radius.
Ohshima
H
Faculty of Pharmaceutical Sciences and Institute of Colloid and Interface Science, Science University of Tokyo, 12 Ichigaya Funagawara-machi, Shinjuku-ku, Tokyo , 162, Japan