Electrophoretic mobility of a soft particle in a polymer gel medium

Abstract

Approximate analytic expressions are derived for the electrophoretic mobility of a weakly charged spherical soft particle consisting of the particle core covered with a surface layer of polymers in a polymer gel medium. The particle core, the surface polymer layer, and the polymer gel medium may be charged or uncharged. The gel electrophoretic mobilities of a bare hard sphere and a spherical polyelectrolyte are covered as limiting cases. The obtained gel mobility expressions involve neither numerical integration nor exponential integrals and these approximate expressions are found to be in excellent agreement with exact numerical results. It is also found that the obtained mobility expressions reproduce all the correct limiting expressions as well as the previously derived approximate analytic expressions for the soft-particle gel electrophoretic mobility.