Patent ID: 6110309
Filing Date: 2000-08-29
Classification: B01D,Y10T

Abstract:
A method of preparing a polyvinylidene difluoride membrane comprising the steps of:providing a casting dope comprising between about 12% and 20% by weight of polyvinylidene difluoride and between about 0% and 30% by weight of a hydrophilic polymer, dissolved in a solvent;casting the dope to form a thin film;exposing the thin film to a gaseous environment;coagulating the film in a water bath; andrecovering a formed microporous polyvinylidene difluoride polymer membrane, the membrane having a microporous surface comprising minimum pores, an opposite surface comprising maximum pores, and a thickness therebetween, the thickness comprising a porous support formed from filamentous webs of polymer material.