title: Hydrophilic nanofibers as new supports for thin film composite membranes for engineered osmosis.
abstract: Engineered osmosis (e.g., forward osmosis, pressure-retarded osmosis, direct osmosis) has emerged as a new platform for applications to water production, sustainable energy, and resource recovery. The lack of an adequately designed membrane has been the major challenge that hinders engineered osmosis (EO) development. In this study, nanotechnology has been integrated with membrane science to build a next generation membrane for engineered osmosis. Specifically, hydrophilic nanofiber, fabricated from different blends of polyacrylonitrile and cellulose acetate via electrospinning, was found to be an effective support for EO thin film composite membranes due to its intrinsically wetted open pore structure with superior interconnectivity. The resulting composite membrane exhibits excellent permselectivity while also showing a reduced resistance to mass transfer that commonly impacts EO processes due to its thin, highly porous nanofiber support layer. Our best membrane exhibited a two to three times enhanced water flux and 90% reduction in salt passage when  compared to a standard commercial FO membrane. Furthermore, our membrane exhibited one of the lowest structural parameters reported in the open literature. These results indicate that hydrophilic nanofiber supported thin film composite membranes have the potential to be a next generation membrane for engineered osmosis.
authors.affiliation: Department of Chemical and Biomolecular Engineering and Center for Environmental Sciences and Engineering, University of Connecticut, 191 Auditorium Road, Unit 3222, Storrs, Connecticut 06269-3222, United States.
authors.forename: Nhu-Ngoc
authors.initials: NN
authors.lastname: Bui
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: McCutcheon
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D057927:Hydrophobic and Hydrophilic Interactions; D055595:Mechanical Phenomena; D008567:Membranes, Artificial; D057139:Nanofibers / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology / Q000379:methods*; D009757:Nylons / Q000737:chemistry; D009995:Osmosis; D010539:Permeability; D013499:Surface Properties
chemical_list: D000180:Acrylic Resins; D008567:Membranes, Artificial; D009757:Nylons; C010504:polyacrylonitrile