Graphene-Based Advanced Membrane Applications in Organic Solvent Nanofiltration

Owing to the increasing need to mitigate excessive organic solvent waste, the efficient separation and recovery of organic solvents have received major research attention in recent years. The membrane-based organic solvent nanofiltration (OSN) process has demonstrated its feasibility in addressing this problem with low energy costs, compared to conventional separation techniques, such as adsorption, liquid-liquid extraction, and solvent evaporation. Recently, membranes made of 2D graphene-based materials have shown great promise because they attain high solvent flux and solute rejection using easy processing methods. Thus, this paper focuses on state-of-the-art studies of graphene-based membranes used in OSN processes, which include syntheses, characterizations, performance evaluations, membrane fouling, and simulation studies, in combination with the development of the "upper-bound" line to indicate the performance of graphene-based membranes. In this paper, critical challenges involved in the development of graphene-based membranes are also focused on and discussed to map out the future directions of these membranes in industrial OSN processes. In addition to OSN, this paper pertains to a broader audience in other separation processes, particularly in the fields of gas separation and water treatment.