Graphene-based composite membranes for nanofiltration: performances and future perspectives

Nanofiltration is one of the most widely used membrane processes for water purification with high practical value because of a large number of chemical species that are separated through this process. Usually, for nanofiltration, high energy-consuming operations are involved including the generation of enough pressure for the rejection of jumps and lower molecular weight chemicals at the surface of the membrane. Recent developments in the synthesis of nanocomposite membranes with graphene and graphene derivatives have led to an increase in energy requirements and the increase in membranes performances. In the present review, we have presented the recent advances in the field of graphene-based composite membranes for nanofiltration with applications for both types of based solvents-aqueous solutions and organic solvents. The presentation will be focused especially on the performances of membranes and applications of these materials for the rejection of salts (Na+, Mg2+), heavy metals (Li2+), and lower molecular weight organic compounds (methylene blue, Congo red, Direct Red, Methyl orange, Reactive green 13, etc.). Modern synthesis methods like interfacial polymerization for obtaining thin-film composite nanofiltration membranes are also presented.