摘要

We present a continuum approach to predicting the electrophoretic mobility of a charged dielectric colloidal particle in a concentrated multivalent electrolyte. Our model takes into account steric (excluded volume) hindrance between ions via Bikerman's approach (Philos. Mag., vol. 33, 1942, p. 384) and ion-ion electrostatic (Coulombic) correlations via the work of Bazant et al. (Phys. Rev. Lett., vol. 106, 2011, 046102). The latter can result in the prediction of an electrophoretic mobility reversal, that is, the migration velocity of a particle switches direction with increasing ion concentration. Our model predictions compare favourably with experiments that observe mobility reversals in multivalent electrolytes.

  • 出版日期2014-8