Pore clogging caused by microscale particles exists universally in various engineering processes, including transport of biological cells, aerosol filtration, assay applications of colloidal particles, and microreactors. We perform computer simulations based on adhesive contact mechanics to demonstrate the clogging process of charged microparticles at the single-pore level. Results indicate that the repulsion among particles delays or even totally prevents the formation of clogs. A clogging phase diagram, with respect to the driving pressure and a proposed charge parameter κ_q, is constructed to quantify the clogging-nonclogging transition. In addition, a critical state, where the capture efficiency of particles decreases to its minimum, is identified as a clogging-nonclogging criterion for repulsive particles. The distributions of the local volume fraction show that the structure of clogs is mainly determined by short-range adhesion. With relatively strong adhesion, a loose clog will be formed and it is easier for particles to penetrate.

Publication: Chen S, Liu WW, Li SQ*. Effect of long-range electrostatic repulsion on pore clogging during microfiltration. Physical Review E, 94(6): 063108 (2016).