Patent ID: 8722146
Filing Date: 2014-05-13
Classification: B01D

Abstract:
1. A method for making a liquid separation membrane, the method comprising: a) providing a polyvinylidene fluoride liquid separation membrane or polypropylene liquid separation membrane prepared by a thermally induced phase separation method as a substrate membrane, soaking the substrate membrane with water or a weak polar organic liquid to make membrane pores of the substrate membrane filled with the liquid, the soaking time being between 0.5 s and 1 min, wherein the weak polar organic liquid is ethanol, glycerin, isopropyl alcohol, or polyethylene glycol having a molecular weight of less than 600; and b) coating a casting solution of polyvinylidene fluoride on the surface of the soaked substrate membrane obtained in step (a), and quickly soaking the substrate membrane in a coagulating bath heated to a temperature of 60-100° C. for curing to yield the liquid separation membrane.