Design of a novel interfacial enhanced GO-PA/APVC nanofiltration membrane with stripe-like structure

Abstract

New-style thin film composite nanofiltration (TFC NF) membrane with a stripe-like surface structure, superior interfacial bonding, expected permeability and antifouling performance was successfully fabricated via interfacial polymerization. The aminated polyvinyl chloride (APVC) membrane prepared by amination reaction of polyvinyl chloride (PVC) with triethylenetetramine (TETA) was used as the support layer. The new graphene oxide-polyamide (GO-PA) selective layer was formed by adding graphene oxide (GO) to the aqueous solution to participate in the interfacial polymerization process. The effects of amination modification of PVC substrate membrane and addition of GO during the interfacial polymerization on the structure and performances of the TFC NF membranes were studied. The results indicated that both of the amine group on the surface of the APVC membrane and GO participated in the interfacial polymerization, which endowed the GO-PA/APVC membrane with a new-style stripe-like surface structure and a thicker, gradually looser cross-sectional structure. Meanwhile, the effective desalination active layer of the GO-PA/APVC membrane was much thinner than that of the PA/APVC membrane. The special structure was beneficial to accelerate the speed of water transmission and effectively overcome the trade-off effect during the desalination process. Therefore, the water permeability of GO-PA/APVC membrane was improved more than 60% while the salt rejection remained stable compared with PA/APVC membrane. Moreover, the GO-PA/APVC membrane exhibited superior interfacial bonding and antifouling properties.