Developing composite nanofiltration membranes with highly stable antifouling property based on hydrophilic roughness

Membrane fouling is still an inevitable main challenge to nanofiltration (NF) process, which leads to a decline in membrane performance. Inspired by fish scales, a facile method was performed to develop composite NF membranes with highly stable antifouling property based on hydrophilic roughness. γ-(2,3-glycidyloxy) trimethoxysilane (KH560) grafted onto PEI molecules during interfacial polymerization on hydrophilic microporous PTFE support. Finally, tetraethyl orthosilicate (TEOS) reacted with KH560 molecules. Results of fourier transform infrared (FTIR) spectra, FESEM and contact angle measurements indicated that micro/nano hydrophilic SiO2 spheres engendered on the membrane surface. Evaluation of membrane antifouling property showed that flux recovery ratio (FRR) of BSA, HA, SDS and Oil/water mixture for the as-prepared NF membranes were 96.0%, 95.8%, 96.8% and 95.0%, respectively. No obvious permeate flux decline and rejection fluctuation could be observed in filtration experiment of MgSO4 aqueous solution on long-term run (100 h). It indicated highly stable antifouling property, which may be due to hydrophilic microscale/nanoscale SiO2 spheres grafted onto the skin layer of the as-prepared NF membranes through chemical linkage. It is expected that these findings could provide more insight for fabrication and simultaneous modification of NF membranes.