Hollow fiber microfiltration membranes and a method of making these membranes
First Claim
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 μ
m and an average pore size of about 0.15 to 0.3μ
m.
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Accused Products
Abstract
A hollow fiber microfiltration (MF) membrane is provided. The casting solution used to make this membrane includes a fiber-forming polymer having a degree of polymerization greater than about 1000, a water-soluble polymer, an anhydride with about 2 to 12 carbon atoms, and a solvent. The membrane is formed by mixing and heating these components to form a viscous dope and then extruding the dope through an annular orifice to form a hollow fiber MF membrane. The hollow fiber membrane is then fed through a coagulation bath and two leaching baths. The membrane is especially useful for filtering liquids, such as wine and juice, so as to remove bacteria, gel, and solid particles from the liquids.
122 Citations
10 Claims
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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 μ
m and an average pore size of about 0.15 to 0.3μ
m. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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Specification