US Patent 7913857 Selective membrane having a high fouling resistance

A selective membrane having a high fouling resistance. In one embodiment, the selective membrane is a composite polyamide reverse osmosis membrane in which a hydrophilic coating is applied to the polyamide layer of the membrane, the hydrophilic coating being made by covalently bonding a hydrophilic compound to residual acid chlorides of the polyamide membrane, the hydrophilic compound including (i) at least one reactive group that is adapted to covalently bond directly to the polyamide membrane, the at least one reactive group being at least one of a primary amine and a secondary amine; and (ii) at least one non-terminal hydroxyl group.