Spin-assisted interfacial polymerization strategy for graphene oxide- polyamide composite nanofiltration membrane with high performance

摘要

Graphene oxide (GO) has been addressed to have greatly potential in nanofiltration membranes. The state-of-the-art GO-based nanofiltration is still limited by the low permeability and instability for the large-scale industrial application. Herein, we developed a novel interfacial polymerization technology for high permeability and advanced stability GO-polyamide membrane with the help of spin. The high-rough microfiltration membrane was chosen as the substrate for providing large effective filtration area and trapping GO nanosheets in valley structures. Aided with centrifugal force field from the spin, the excess low concentration amine monomer solution could be removed homogeneous to form ultrathin and defect-free polyamide (PA) layer. The pure water permeability of the graphene oxide-polyamide (GO-PA) composite nanofiltration membrane could be up to 35.14 LMH/bar with Na2SO4 rejection of 93.56% at 4 bar, which is comparable to the top permeability of GO-based nanofiltration membranes with the similar salt rejection that has been reported. The membranes also behave high Na2SO4/NaCl selectivity (15-56) due to the extremely low NaCl rejection. In addition, the GO-PA composite nanofiltration membranes exhibit good stability in harsh environment and solvents. This work promotes GO-based nanofiltration for practical applications and provides a novel route for high-performance nanofiltration membranes.