High-throughput asymmetric membrane

Abstract

A microporous asymmetrical membrane formed of one or more layers wherein the “tight” side of the membrane has an “opened” face or otherwise highly-porous reticulated surface is described. The microporous asymmetrical membrane has high throughput and high flux, even when used for filtering viscous materials, such as serum or plasma. The membrane's surface can be formed by ablation or solvation, or in a two or more layered structure, through an appropriate selection of casting dopes.

1 . An asymmetrical microporous membrane comprising polymeric material having a tight side and an open side, and the tight side has an open highly porous surface, wherein the membrane has a bubble point normalized serum flow time of less than about 2. 
   
   
       2 . The membrane of  claim 1 , wherein the average distance between pores on the tight side is about 0.4 microns. 
   
   
       3 . The membrane of  claim 1 , wherein the polymeric material is chosen from PVDF, nylons, polyamides, polyimides, polyethersulphones, polysulphones, polyarylsulphones, PVC, PET, polycarbonates, cellulose, regenerated cellulose, cellulose esters, polystyrenes, polyetherimides, acrylic polymers, methacrylic polymers, copolymers of acrylic or methacrylic polymers, or blends of any of the above. 
   
   
       4 . An asymmetric microporous membrane comprising an open highly porous tight side, wherein the open highly porous tight side comprises at least one of the following:
 a) an average distance between pores of about 0.4 microns;   b) a tight surface porosity as measured by fractionated area percent of about 16; and   c) a gloss measurement of about:
 i) 9.5 at a light angle of 60°; 
 ii) 64 at a light angle of 85°; 
 iii) 1.6 or less at a light angle of 20°. 
   
   
   
       5 . The membrane of  claim 4  wherein the membrane is a multi-layered membrane. 
   
   
       6 . The membrane of  claim 1 , wherein the membrane is a single layered membrane. 
   
   
       7 . The membrane of  claim 1 , wherein the membrane is a multi-layered membrane. 
   
   
       8 . The membrane of  claim 1  wherein the membrane is a multi-layered membrane. 
   
   
       9 . An asymmetric microporous membrane comprising a tight side an aopen side wherein the tight side has an open porous surface with an average distance between pores of about 0.4 microns. 
   
   
       10 . The asymmetric microporous membrane of  claim 9 , wherein the membrane is a multi-layered membrane. 
   
   
       11 . The asymmetric microporous membrane of  claim 9 , comprising a polymeric material chosen from PVDF, nylons, polyamides, polyimides, polyethersulphones, polysulphones, polyarylsulphones, PVC, PET, polycarbonates, cellulose, regenerated cellulose, cellulose esters, polystyrenes, polyetherimides, acrylic polymers, methacrylic polymers, copolymers of acrylic or methacrylic polymers, or blends of any of the above. 
   
   
       12 . The membrane of  claim 9 , wherein the membrane has a bubble point normalized serum flow time of less than about 2. 
   
   
       13 . The membrane of  claim 9 , wherein the membrane has a tight surface porosity as measured by fractionated area percent of about 16. 
   
   
       14 . The membrane of  claim 9 , wherein the membrane has a gloss measurement of about:
 i) 9.5 at a light angle of 60°;   ii) 64 at a light angle of 85°;   iii) 1.6 or less at a light angle of 20°.