Surface patterning of polymeric membranes and its effect on antifouling characteristics

Surface roughness of membranes is often perceived by many as a factor that promotes fouling during filtration, and thus is undesirable. Almost all liquid-based separation membranes display flat surfaces with an intrinsic surface roughness that is associated with the membrane manufacturing process. Recently, polymer ultrafiltration and thin film composite membranes containing regular, periodic surface patterns were fabricated using cost-effective lithographic methods. Here, we review the work to date on the fabrication and characterization of these patterned membranes with a focus on processing-structure-performance relationships. In addition, the antifouling performance of these membranes against model foulants including colloidal suspensions and protein solutions is also highlighted.