Graphene oxide based membrane intercalated by nanoparticles for high performance nanofiltration application

A free-standing sandwich-structured polyamide 6 (PA 6)@GO@PA 6 nanofiltration membrane intercalated by nanoparticles with high water flux was prepared using electrospraying combined with electrospinning method. According to the XRD patterns, the interlayer spacing of the membrane increases with the TiO2 nanoparticle (NP) intercalated. The TiO2 NP intercalated PA 6@GO (120)@ PA 6 nanofiltration membrane shows a pure water flux up to 13.77 Lm(-2) h(-1) bar(-1) even under an extremely low external pressure (1.0 bar), which increased by 80.7% than that of PA 6@GO (120)@ PA 6 nanofiltration membrane (7.62 Lm(-2) h(-1) bar(-1)) without nanoparticles intercalated, and maintains high organic dye rejection capabilities (> 85% for BF, > 92% for MB, > 99% for MO, and 99.85% for EB). Besides TiO2, other nanoparticles, such as SiO2 and Si3N4 can also improve the water flux and maintain high rejection rate for MO and MB. Furthermore, TiO2 intercalated PA 6@GO (120)@ PA 6 nanofiltration membrane is very stable even under ultrasonication, and shows a high flux for some common solvents (12.32, 4.91, and 1.26 Lm(-2) h(-1) bar(-1) for methanol, ethanol, and NMP, respectively).