Reparation Of Graphene Oxide Composite Nanofiltration Membrane

As one of the emerging membrane technology,nanofiltration membrane technology has widely been used because of its energy saving,environmental protection,high efficiency and easy operation,especially in the field of water treatment.The surface of NF membrane can be usually charged,therefore,its separation mechanism is different from that of the ordinary separation membrane.The NF membrane can separate components not only by the pore size,but also by the electrostatic interaction and the surface of the NF membrane.Most of the traditional NF membranes are composite membranes,and there are some shortcomings such as poor stability,low fouling resistance ability,low water flux and low rejection of ions.Consequently,it is crucial to develop a high performance membrane material to solve the problem of traditional NF membrane.In this study,graphene oxide,a new type of nanomaterial was used as a membrane material to prepare NF membrane with good performance,and the GO was composited on the dopamine-modified polysulfone membrane.In order to improve the stability of NF membrane,graphene oxide was layer-by-layer crosslinked by 1,3,5-benzenetricarbonyl trichloride(TMC).Performance test results show that,the prepared GO composite NF membrane(M-GO)possesses relatively superior performance:(1)the membrane had a high rejection of organic dyes and anions,the rejection of methyl blue and PO43-was respectively about 98%,92%and had a high water flux 70(kg·m-2· h-1),120(kg·m-2· h-1);(2)the membrane had strong aiti-fouling and stability,for example,the flux recovery rate(FRR)was up to 90%;(3)FT-IR and XPS analyses showed that graphene oxide was successfully composited to the membrane surface.Zeta potential was about-183.4 mV,which showed the membrane surface had amounts of negative charge.The contact angle analyses showed that the membrane hydrophilic was greatly improved,and the contact angle of the membrane surface was about 36°.