Patent ID: 7517482
Filing Date: 2009-04-14
Classification: B01D

Abstract:
1. A method for preparing polymeric membranes, comprising the steps of following: (a) forming a casting solution by dissolving 0.5 wt % to 18 wt % cellulose triacetate (CTA) based on the total weight of the casting solution and 7.0 wt % to 25 wt % polyether-sulfone (PES) based on the total weight of the casting solution in a solvent mixture containing n-methyl pyrroridone (NMP) and from 0.3% to 2.0% based on the total weight of the casting solution of hydrogen chloride (HCl) at a temperature of 70° C. to 90° C. (b) forming a membrane from said casting solution; (c) precipitating said membrane in a precipitation bath; and (d) washing and drying said membrane.