Dielectrophoresis in surface fouling prevention

Abstract

AC Dielectrophoresis, the motion of dielectric colloidal particles in the presence of an inhomogeneous AC electric field, has been utilized in this work as a mechanism for preventing channel wall fouling due to particle deposition for a multi-component colloidal system. Both attractive and repulsive DEP force fields were examined in aqueous suspensions of silica and polystyrene particles. Under a continuous cross-flow condition in a rectangular channel, particle movement away from the channel wall was visualized when a repulsive DEP force field was applied. In order to achieve a cleaner channel wall, the effect of various parameters, such as, frequency and amplitude of the AC signal, cross flow velocity, particle size and density on the particle levitation were investigated for both single-component and binary colloidal suspensions. The results also depict that the levitation of the individual species can be further controlled in order to achieve selective adsorption or field flow fractionation.