Development of defect-free thin film nanocomposite membranes for desalination using recycled PET and 2D nanomaterials

Abstract

Abstract This study investigates the development and properties of the thin film nanocomposite (TFNC) desalination membranes based on electrospun recycled polyethylene terephthalate (rPET) substrate layers. However, achieving a defect-free thin film active layer onto the highly porous electrospun nanofibrous membranes (ENMs) remains challenging. The ENM was thus modified with graphene oxide/ molybdenum disulfide (GO/MoS 2 ) to develop the defect-free TFNC membrane. Graphene oxide (GO) nanosheets were intercalated with MoS 2 and crosslinked polymer connectors. These as-prepared laminate layers were deposited onto the rPET nanofibers to function as an interlayer or transition layer, between the electrospun substrate and the thin film active layer. The resultant rPET-GO/MoS 2 membrane was assessed in terms of physicochemical properties and performance. The hydrophilicity was greatly enhanced by the GO/MoS 2 interlayer, from 120 ° to 67°. The XRD supplied the evidence of successful intercalation of MoS 2 within the GO sheets thus resulting in the tightening of the interlayer space within the sheets of the GO-MoS 2 membranes, from 0.86 nm for GO to 0.79nm for GO/MoS 2 . The nanochannel spacing of the GO-MoS 2 membranes was thus capable of retaining the salt ions during desalination. The properties of the tailored membrane, therefore, highlight the potential of electrospun membranes and 2D nanomaterials in offering sustainable materials towards ensuring continuous and economical water supply in emerging water supply alternatives such as desalination.