11 / 2017-05-10 03:15:17

Enhanced Fouling Resistance from Surface Patterning of Polymeric Membranes

13922,6436,13923,13924

Surface roughness of membranes is often perceived as a factor that promotes fouling during filtration, and thus is undesirable. Almost all liquid-based separation membranes have surfaces that are flat on the macroscale but with local intrinsic surface roughness that is associated with the membrane manufacturing process. In this presentation, we show that surface patterns, i.e. engineered roughness, on membrane surfaces can improve their fouling resistance during microfiltration (MF), ultrafiltation (UF), nanofiltration (NF) and reverse osmosis (RO) separation processes. We will describe the underlying mechanisms and the corresponding processing-structure-performance relationships for surface patterning of different types of membranes. Comprehensive experimental studies using model suspensions of colloid and protein foulants as well as salt solutions reveal that the presence of the surface patterns can significantly improve overall filtration productivity and regeneration characteristics of the patterned membranes in comparison to that of non-patterned controls. Based on fluid mechanics modeling studies, the enhancement in performance was attributed to pattern-enhanced fluid shear.