Patent ID: 6890435
Filing Date: 2005-05-10
Classification: B01D,D01D

Abstract:
1. A hollow fiber microfiltration membrane, said membrane being prepared from a mixture comprising: about 12-30% by weight polysulfone polyethersulfone, polyvinyledene fluoride or mixtures thereof; about 8-25% by weight polyvinylpyrrolidone; about 8-25% by weight maleic anhydride; and an aprotic solvent, wherein said mixture is extruded through an annular orifice using a bore fluid comprised of N-methyl pyrrolidone, polyethylene glycol, and isopropylnol and then fed through a gelation bath comprised of water and N-methyl pyrrolidone to form said hollow fiber microfiltration membrane wherein said membrane has a narrow quasi Gaussian pore size distribution of about 0 to 0.3 μm and an average pore size of about 0.15 to 0.3μm.