Whatman Gmbh

Costar Corporation

Corning Costar Corporation

Manuel M Pacheco

John F Pacheco

Dean T Tsou

Oksana Penezina

Dean T c/o American Membrane Corporation Tsou

The invention provides composite porous membranes comprising a porous hydrophobic substrate coated with difunctional surface-modifying molecules. The difunctional surface-modifying molecules provide a hydrophilic surface without forming branches of interconnected polymer molecules in the pores. The invention also provides a method for making composite porous membranes, such as a composite hydrophilic membrane with reduced concentration of surface modifying molecules required to coat a hydrophobic substrate.

Porous composite membrane and method for making the same

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.

PVDF microporous membrane and method

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.

Microporous membranes having supporting structures are disclosed. A microporous filtration membrane made of a polymeric material has an integral support, both the support and the membrane having substantially identical chemical composition. Preferred supported membranes of the present invention are made of polyvinylidene fluoride. At least part of the support is bonded to the surrounding microporous membrane to provide rigidity and chemical inertness. Methods of forming the supported microporous membranes are described, including a method that results in microporous membranes having unique structural and functional characteristics.

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Billerica, MA, United States of America

Manuel M Pacheco