In an effort to reduce fouling, enhance membrane cleaning, and flux recovery, a hydrophilic polymer with amine functionality was grafted onto an active porous membrane surface. Poly(ethylene glycol) bis-(3-aminopropyl) terminated molecules were grafted on polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene-graft-maleic anhydride via condensation reaction between the anhydride ring and amine group. Structural analysis, hydrophilicity, water permeability, and rejection performance of the membranes were assessed for its suitability in separation and water purification processes. The hydrophilicity, permeability, and solute rejection property of the membranes increased upon anchoring of amino terminated PEG brushes. The good antifouling behavior (for protein and bacteria) and pure water permeability along with high rejection property showed its suitability for water purification and separation processes.