Method for preparing durably hydrophilic and uniform-pore ultrafiltration membrane

A method for preparing a durably hydrophilic and uniform-pore ultrafiltration membrane, the method comprising the steps of:

• a) combining a polymer membrane material with reactive sites, reactive active hydrophilic molecules having hydrophilic chains, a membrane-forming porogen, and a solvent at constant temperature under conditions suitable to dissolve the polymer membrane material and to graft the reactive active hydrophilic molecules to the reactive sites, to derive a hydrophilized polymer solution having the polymer membrane material dissolved therein, with the hydrophilic chains of the reactive active hydrophilic molecules grafted to the reactive sites;
• b) introducing the hydrophilized polymer solution into a coagulation bath to initiate a crosslinking reaction among the hydrophilic chains grafted to the reactive sites to form a hydrophilized polymer solution have a crosslinked network;
• and
• c) performing a dry-wet phase separation process upon the hydrophilized polymer solution having a crosslinked network to produce an ultrafiltration membrane, the ultrafiltration membrane having an improved membrane-pore structure due to the crosslinked network synergistically restricting both the movement of polymer chains and the formation and growth of micelles during the dry-wet phase separation process.