Direct Numerical Simulations of Electrophoresis of Charged Colloids

TL;DR

This paper introduces a comprehensive numerical simulation method for electrohydrodynamic behavior in charged colloids, accurately modeling particle, ion, and fluid interactions to predict electrophoretic mobilities.

Contribution

It presents a novel numerical approach that fully accounts for electrohydrodynamic couplings in colloidal dispersions, improving predictions especially in dense systems.

Findings

Quantitative agreement with theories for dilute dispersions.

Deviations observed in dense dispersions.

Method enables detailed simulation of electrohydrodynamic phenomena.

Abstract

We propose a numerical method to simulate electrohydrodynamic phenomena in charged colloidal dispersions. This method enables us to compute the time evolutions of colloidal particles, ions, and host fluids simultaneously by solving Newton, advection-diffusion, and Navier--Stokes equations so that the electrohydrodynamic couplings can be fully taken into account. The electrophoretic mobilities of charged spherical particles are calculated in several situations. The comparisons with approximation theories show quantitative agreements for dilute dispersions without any empirical parameters, however, our simulation predicts notable deviations in the case of dense dispersions.