Regardless of the membrane type, flat sheet, hollow fiber, and electrospun nanofibers, the easiest way for hydrophilization of the membranes is by blending hydrophilic additives with the polymer/solvent dope solution. If you are not seeking new hydrophilic additives, you can easily use PVP and PEG that are hydrophilic polymers and completely blend with your dope solution without following a special procedure.