Particle deposition on the patterned membrane surface: Simulation and experiments

• Particle deposition on the patterned membrane was studied by simulation and experiment.
• Brownian dynamics simulation reproduced particle deposition shown in the experiment.
• Less particles were deposited in the apex region of the prism pattern.
• Particles were detached from the surface where the local wall shear stress was high.

Mitigation of membrane fouling is important for the sustainable operation of waste-water treatment. A wide range of physical, chemical and biological anti-fouling techniques has been proposed to reduce membrane fouling. Through these efforts, patterned membranes on which micro-sized surface patterns are engraved are known to exhibit effective anti-fouling performance without any chemical or biological treatment. To optimize anti-fouling properties of patterned membranes, particle deposition on the patterned membrane surface needs to be understood. In this study, both Brownian dynamics simulation and particle deposition experiments were conducted to understand the mechanism of particle deposition on the patterned membrane surface. A model experimental system was developed, in which poly(methyl methacrylate) (PMMA) colloidal suspension was pumped into a microfiltration module containing a patterned membrane. Stagnant flow zone was formed in the valley region of the surface pattern, in which more particles were deposited. High shear stress was distributed near the apex region, where few particles were deposited. Both the simulation and the experimental results confirmed these observations. Flow characteristics near the patterned membrane surface were found to be strongly correlated with the particle deposition. This study will provide a useful insight for the design of efficient micro-structured membranes.