Fouling by suspended solids and dissolved organic matters presents a great challenge for polymeric membranes for desalination and wastewater treatment. With superior hydrophilicity, zwitterionic materials have been explored for membrane surface modification to enhance antifouling properties. In this study, we have developed a facile one-step coating of superhydrophilic zwitterions on the surface of ultrafiltration (UF) membranes, aiming to reduce the fouling. More specifically, three commercial UF membranes, PES-2, PAN-50, and PS-100 are coated with a solution containing dopamine and sulfobetaine methacrylate (SBMA). The dopamine provides adhesion to the membrane surface and it also anchors SBMA via Michael addition to form a thin hydrophilic layer on the surface. The coating enhances the surface hydrophilicity, as confirmed by contact angle measurement. The effect of composition of the coating solutions and coating time on the water flux through the modified membranes is investigated. The membranes coated with SBMA demonstrate higher water flux than uncoated ones, when tested with water containing bovine serum albumin (BSA) using a crossflow system. For instance, the modified PES-2, PAN-50, and PS-100 with SBMA show improved water permeance by 65%, 81%, and 61%, respectively, compared to analogous uncoated ones after 3 h filtration using a 3 g/L BSA solution. This facile modification has been applied to commercial membrane modules as a post-treatment. This presentation will also discuss a field test of these membrane modules for wastewater reuse.

Facile grafting of zwitterions onto membrane surface to improve antifouling properties for wastewater reuse

253rd National Meeting (2017)

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