Influence of chemical coating combined with nanopatterning on alginate fouling during nanofiltration

This contribution describes a method to increase the fouling resistance of nanofiltration membranes by applying both a chemical coating and a nanoscale pattern to the membrane surfaces. A line and groove nano-pattern was applied by thermal embossing directly onto a commercial polyamide thin-film composite nanofiltration membrane. Poly(ethylene glycol) diglycidyl ether (PEGDE) was reacted onto the patterned membrane surfaces by an epoxide ring opening reaction with unreacted carboxyl groups on the polyamide selective layer. Membrane performance was evaluated by measuring flux and salt rejection using a magnesium sulfate solution and by measuring flux reduction using an alginate solution. Surface characterization showed successful patterning and chemical modification of the membrane surface. Flux and salt rejection properties were unaffected by patterning the polyamide membrane surface directly. The fouling results show that combining line and groove nano-patterning with PEGDE chemical modification yields a membrane that is more resistant to fouling than either method alone. (C) 2016 Elsevier B.V. All rights reserved.