Transient electrophoresis of a spherical colloidal particle with a slip surface

Transient dynamic electrophoresis of a spherical colloidal particle

A general theory is presented for the transient dynamic electrophoresis of a spherical colloidal particle in an electrolyte solution under a suddenly applied oscillating electric field. An approximate analytic expression is derived for the transient dynamic electrophoretic mobility, which is applicable for low particle zeta potentials and arbitrary Debye length. It is found that the electrophoretic mobility shows a damped oscillation, approaching its final value, unlike the case where a step electric field is applied.

Transient dynamic electrophoresis of a soft particle

We introduce a general theory that explains the transient dynamic electrophoresis of a soft particle in an electrolyte solution when an oscillating electric field is suddenly applied. A simple approximate analytic expression is derived for the transient dynamic electrophoretic mobility of a soft particle that can be applied to practical situations. It is found that the mobility shows a damped oscillation, approaching its final value, similar to the behavior of a hard particle.

Transient Gel Electrophoresis of a Spherical Colloidal Particle

The general theory is developed for the time-dependent transient electrophoresis of a weakly charged spherical colloidal particle with an electrical double layer of arbitrary thickness in an uncharged or charged polymer gel medium. The Laplace transform of the transient electrophoretic mobility of the particle with respect to time is derived by considering the long-range hydrodynamic interaction between the particle and the polymer gel medium on the basis of the Brinkman-Debye-Bueche model. According to the obtained Laplace transform of the particle's transient electrophoretic mobility, the transient gel electrophoretic mobility approaches the steady gel electrophoretic mobility as time approaches infinity. The present theory of the transient gel electrophoresis also covers the transient free-solution electrophoresis as its limiting case. It is shown that the relaxation time for the transient gel electrophoretic mobility to reach its steady value is shorter than that of the transient free-solution electrophoretic mobility and becomes shorter as the Brinkman screening length decreases. Some limiting or approximate expressions are derived for the Laplace transform of the transient gel electrophoretic mobility.