Porous composite membrane and method for making the same

A composite porous membrane comprising:

• a hydrophobic substrate having an average pore size ranging from about 0.01 μm to about 10 μm coated with difunctional surface-modifying molecules;
• each difunctional surface-modifying molecule comprising a hydrophobic portion preferentially associated with the substrate and a hydrophilic portion and having an active group containing a carbon-carbon double bond;
• the difunctional surface-modifying molecules consisting of a difunctional acrylate monomer;
• wherein the difunctional acrylate monomer comprises greater than about 90% of the molecules associated with the membrane;
• wherein the substrate is coated by flowing a reagent solution through the substrate to coat the substrate surface and inner surfaces of the pores, the reagent solution consisting of the difunctional surface-modifying molecules, a solvent, and a photoinitiator, wherein the reagent is capable of flowing through the substrate;
• and
• wherein the surface-modifying molecules are crosslinked to form a crosslinked hydrophilic polymeric network at the substrate surface and inner surfaces of the pores of the membrane, and wherein the pore size of the coated membrane is substantially the same as the pore size of the porous membrane before coating.