Patent ID: 8528746

Claim:
A method of manufacturing a hydrophilic membrane having improved antifouling property using a supercritical fluid or a subcritical fluid, the method comprising: introducing a hydrophilic group-containing monomer, an initiator and a cross-linking agent into a high pressure solution vessel, introducing a supercritical fluid or subcritical fluid into the high, thereby dissolving a mixture of the hydrophilic group-containing monomer, initiator and cross-linking agent in the supercritical fluid or subcritical fluid to prepare a coating solution (Step 1); fixing membranes onto an internal heater in a high pressure coating vessel, pressurizing the high pressure coating vessel such that a pressure of the high pressure coating vessel is identical to that of the high pressure solution vessel, and transferring coating material from the high pressure solution vessel to the high pressure coating vessel to contact the coating material with the membranes (Step 2); coating the monomer, initiator and cross-linking agent contacted with the membranes in Step 2 on surfaces and micropores of the membranes through a cross-linking reaction and a polymerization reaction (Step 3); lowering temperature of the internal heater in the high pressure coating vessel and transferring non-reacted coating material to the high pressure solution vessel again (Step 4); and lowering pressure of the high pressure coating vessel to the atmospheric pressure, recovering manufactured hydrophilicized membranes, and cleaning and drying the recovered hydrophilicized membranes (Step 5).