Footsteps of graphene filled polymer nanocomposites towards efficient membranes—Present and future

Due to rising global environmental challenges, air/water pollution treatments technologies especially membrane techniques have been focused. In this context, air or purification membranes have been considered effective for environmental remediations. In the field of polymeric membranes, high performance polymer/graphene nanocomposite membranes have gained increasing research attention. The polymer/graphene nanomaterials exposed several potential benefits when processed as membranes. This review explains utilizations of polymer and graphene derived nanocomposites towards membranes formation and water or gas separation or decontamination properties. Here, different membrane designs have been developed depending upon the polymer types (poly(vinyl alcohol), poly(vinyl chloride), poly(dimethyl siloxane), polysulfone, poly(methyl methacrylate), etc.) and graphene functionalities. Including graphene in polymers influenced membrane microstructure, physical features, molecular permeability or selectivity, and separations. Polysulfone/graphene oxide nanocomposite membranes have been found most efficient with enhanced rejection rate of 90%–95%, high water flux >180 L/m2/h, and desirable water contact angle for water purification purposes. For gas separation membranes, efficient membranes have been reported as polysulfone/graphene oxide and poly(dimethyl siloxane)/graphene oxide nanocomposites. In these membranes, N2, CO2, and other gases permeability have been found higher than even >99.9%. Similarly, higher selectivity values for gases like CO2/CH4 have been observed. Thus, high performance graphene-based nanocomposite membranes possess high potential to overcome the challenges related to water or gas molecular separations.