Thin Film Composite Membranes for Forward Osmosis Supported by Commercial Nanofiber Nonwovens

Nanofiber-supported thin film composites (TFC) for forward osmosis (FO) have shown great promise as viable FO membranes in comparison to commercially available forward osmosis membranes. In numerous studies on the subject, nanofiber supports for TFC membranes are commonly made by electrospinning. In this study, we have chosen a different nanofiber medium to use as a support for a FO TFC membrane. This nonwoven, which is a commercially available nanofiber mat, is from E.I. du Pont de Nemours and Company (DuPont). This unique nanofiber-based nonwoven is produced as long rolls and is unsupported, unlike other nanofiber products that are produced on top of a typical spunbond or wetlaid nonwoven due to the lack of mechanical integrity. The DuPont PES material demonstrated better strength than typical electrospun materials and was used to support a polyamide selective layer formed by in situ interfacial polymerization. The DuPont PES TFC membrane was tested in FO and found to generate twice the water flux and one-tenth the reverse solute flux compared to a commercial TFC FO membrane. The membrane was also found to match the performance of laboratory-based electrospun-nanofiber-supported TFC but exhibited better selectivity and strength.