MICROFILTRATION MEMBRANES HAVING HIGH PORE DENSITY AND MIXEDISOTROPIC AND ANISOTROPIC STRUCTURE

The present invention relates to the field of synthetic polymeric microfiltration membrane materials that are fabricated to separate liquids from solids contained therein. One aspect of the invention relates to a sulfone polymer membrane with high surface porosity (high pore density) and distinctive asymmetry that can separate solids (i.e., blood cells) from a liquid (i.e., plasma) without the need for centrifugation. The membrane is further rendered hydrophilic through co-casting the sulfone polymer (which is a hydrophobic polymer) with a hydrophilic polymer, such as polyvinylpyrrolidone. Because of these properties and the fact that it requires only a small amount of the solid containing liquid (i.e., whole blood) to be applied to the larger pore surface, the membranes of the invention are highly useful in testing devices for the quick detection of properties or components contained in liquid samples, such as diagnostic applications (i.e., the detection of physiological conditions (i.e., pregnancy, insulin level, stomach ulcer, and the like) and infectious diseases (i.e., AIDS, hepatitis, and the like)).