A membrane made of a polymeric support, and an active layer with a polyamide grafted with a copolymer on the polymeric support. The copolymer is reacted units of a diallyldimethylammonium chloride (DADMAC), 3-(N,N-diallyl-N-methylammonio)propanesulfonate (DAMAPS), and N,N-diallyldodecane-1,12-diamine (DADA), and the copolymer is grafted to the polyamide with a linking molecule. Further, a method of making the membrane by dissolving an amine and the copolymer in water to form an aqueous solution, dissolving TMC in an organic solvent to form an organic mixture, pouring the aqueous solution onto a polymeric support and then pouring the organic mixture onto the same support for form a coated support, and heating the coated support to form a membrane.

Methods of producing membranes, and membranes for metal and/or hydrocarbon removal. The methods include synthesizing an amine-modified metal oxide, wherein the amine-modified metal oxide comprises a metal oxide component and a water-soluble amino acid derivative having a 1:1 ratio of metal oxide components to water-soluble amino acid derivative; dissolving a water-soluble polymer and a polyvinylidene fluoride and the amine-functionalized metal oxide to form a polymer solution; casting the polymer solution into a mold to form a substrate membrane; coating the substrate membrane with a polyamide; and forming a membrane, wherein the amine-functionalized metal oxide is covalently connected to the polyvinylidene fluoride.