Importance

Loading Importance Indicators...

Abstract

Methods for making microporous polyvinylidene fluoride (PVDF) membranes from vinylidene fluoride polymers and the products produced. The PVDF microporous membranes have a significantly faster flow rate at a given pore size as compared to equally-sized microporous membranes made by conventional procedures. The PVDF microporous membranes also have significantly smaller pore sizes than conventional microporous PVDF membranes. The present membranes have unique macrostructural features responsible, in part, for their unique functional properties. The process includes dissolving the polymer in a liquid that includes a solvent and a co-solvent for the polymer. The dissolution of the polymer can be at temperatures ranging from about 20.degree. C. to about 50.degree. C. while the formation of the microporous membrane can be at temperatures ranging from about -10.degree. C. to 50.degree. C. Selection of appropriate operating parameters of temperature and solvent/co-solvent concentration can optimize the membrane at a given nominal pore size, flow rate, and polymer distribution.

Loading the Abstract Image...

First Claim