Click poly(ethylene glycol) multilayers on RO membranes: Fouling reduction and membrane characterization

Membrane fouling is one of the most important challenges in reverse osmosis operation. In this study, low-fouling, poly(ethylene glycol) (PEG) acrylate multilayers were assembled via the layer-by-layer technique on a commercial polyamide reverse osmosis membrane and stabilized using click chemistry. Resistance to fouling of the membrane surface with a model biopolymer increased as the number of PEG bilayers was increased. This trend was consistent with the measured surface contact angles of the membranes and with scanning electron microscopy images before and after fouling experiments. Importantly, the flux through unfouled membranes fell only marginally (9-17%) due to the presence of the multilayer coating. AFM images of the coated and uncoated membranes showed little change in surface roughness, supporting the hypothesis that the coating layer is of thickness in the nanometer range. This coating strategy holds promise for the preparation of membranes that are both high in flux and resistant to fouling. (C) 2012 Elsevier B.V. All rights reserved.