Physical studies of forward osmosis membranes prepared by cross-linking polyvinyl alcohol on electrospun nanofibers

Abstract

The conventional nanofiber-supported forward osmosis (FO) membrane possessed some issues, for example, easy deformation and weak interfacial strength between the substrate and selective layer. A dual-layered composite membrane consists of electrospun nanofibrous membranes (ENMs) as the support layer and cross-linked polyvinyl alcohol (PVA) top coating as the active layer is fabricated. Hence, the objective of this work is to study the physical properties of the prepared PVA/ polyvinylidene fluoride (PVDF) composite membranes. The novelty of this work relies on the new exploitation of the prepared dual-layered thin film nanofibrous composite (TFNC) membranes via the cross-linked technique in the FO process. The experiment works include the fabrication of nanofibrous substrates and selective layer via electrospinning, followed by the PVA cross-linking process prior to the characterisation studies and FO evaluation. FO performance test revealed a comparable water flux with the conventional dual-layered composite membrane, besides exhibited a significantly low Js/Jw ratio. This study indicated that dual-layered cross-linked PVA on electrospun PVDF nanofibers is a promising approach to overcome the drawback of the existing issues in the conventional method of preparing surface coated composite membranes which is a viable option to manufacture high-performance TFNC-FO membranes.