Cuno, Inc.

W. R. Grace Co.-conn.

Other

Amf Gmbh

Chaokang Chu

Gordon Leeke

George T Emond

Robert G Barnes

Kenneth Southall

Timothy J Webster

Asit K Roy

Ann L Ly

Vish Rai

Ronald V Repetti

Nils Dailey

Scott P Yaeger

Joseph V Fiore

Rodney A Knight

Paul J Marinaccio

Nils L Dailey

Thanh D Nguyen

Richard A Babineau

Asit Roy

Bernard S Liang

Joseph F Ferraro

A casting solution for preparing a low to medium flux membrane. The casting solution contains 19-25% by weight polysulfone, polyethersulfone, or polyarylsulfone; 14-32% by weight a hydrophilic compatible polymer; 0.1-6% by weight an isocyanate capped polyethylene glycol urethane polymer; and 37-67% by weight an aprotic and water miscible solvent; in which the polysulfone, polyethersulfone, or polyarylsulfone has a M.W. of 10,000-100,000 daltons, the isocyanate capped polymer contains 2-5 --N.dbd.C.dbd.O groups per molecule and has a M.W. of 500-5,000 daltons, and the compatible polymer contains 2-5 --CH.sub.2 OH groups per molecule and has a M.W. of 200-1,000 daltons. Also disclosed are a method of spinning this casting solution to form a hollow fiber and the hollow fiber thus obtained.

Low and medium flux membranes

A morphologically heterogeneous, hydrophobic polysulfone hollow fiber membrane comprising a sponge-like dense inner surface permeable to molecules of less than or equal to 30,000 Daltons, said inner surface having a fraction surface porosity from about 70 to about 80%; and an outer surface having large pores ranging from about 6 to about 16 .mu.m in diameter and small pores less than 500.ANG. in diameter and a fractional surface porosity from about 20 to about 30%; a method for producing same and a hemodialysis treatment method and apparatus incorporating same.

High flux hollow fiber membrane

A chromatography column for effecting chromatographic separation of at least two components of a sample flowing through the column. The column comprises a housing and at least one solid stationary phase within the housing. The stationary phase has chromatographic functionality and is effective for chromatographic separation. Means are provided for distributing the sample through the stationary phase and for collecting the sample after the sample has flowed through the stationary phase. The stationary phase comprises:

Chromatography column

Isotropic microporous polysulfone membranes can be prepared by using a particular combination of casting solution and precipitation solution formulations, and casting conditions. Both hollow fiber and flat membranes can be prepared in this manner. The membranes are skinless and are characterized by uniform porosity throughout the membrane.

Process for preparing isotropic microporous polysulfone membranes

A method is provided of manufacturing a skinless, nylon microporous hollow fiber membrane. The method comprises the steps of providing a nylon polymer dope solution and a quench liquid capable of solidifying and forming micropores in an extruded nylon polymer dope solution to produce a skinless, microporous nylon membrane. The quench liquid is placed into a vessel and a tube is provided which has a top and a bottom outlet. The bottom outlet of the tube is partially submerged in the quench liquid, the tube vertically extending therefrom. A spinneret is provided which has an outlet adjacent the top of the tube. The chemical quench liquid is raised in the tube until it is in substantial contact with the spinneret outlet. The nylon polymer dope solution is extruded in the form of a hollow fiber through the spinneret outlet directly into the quench liquid. Extruded hollow fiber is then passed down through the tube and into the vessel, whereby the quench liquid solidifies and forms micropores in the extruded nylon polymer dope solution to thereby form a skinless nylon microporous holow fiber. The fiber is then redirected in the vessel in a generally horizontal direction through the vessel.

Method of manufacturing nylon microporous hollow fiber membrane

A quench bath, for quenching and solidifying an extruded hollow porous fiber of a liquid polymer solution in a chemical quenching solution, includes a shallow quench bath of a length for the generally horizontal part of the extruded fiber travel in the bath. A vertical extension tube with its lower end beneath the surface of the bath liquid holds a spinneret through which the fiber is extruded. The spinneret is sealed in the tube above the height of the liquid in the shallow bath. A vacuum drawn in the tube raises the liquid up to the spinneret. Also, the vacuum may be drawn by disposing the spinneret in a sealing piston which is raised through the tube to draw the vaccum in the tube behind the piston.

Method of manufacturing a hollow porous fiber

A cationic charge modified microporous membrane is provided. The membrane comprises a hydrophilic organic polymeric microporous membrane having bonded thereto, through a cross-linking agent, a charge modifying amount of a cationic charge modifying agent. The charge modifying agent is an aliphatic amine or polyamine, preferably tetraethylene pentamine, and the cross-linking agent is an aliphatic polyepoxide having a molecular weight of less than about 500, preferably 1, 4 butanediol diglycidyl ether. The microporous membrane is preferably nylon. The process for applying the charge modifying agent to the membrane, preferably comprises contacting the membrane with an aqueous solution of the charge modifying agent and then contacting the membrane with a substantially aqueous solution of the cross-linking agent. The preferred process uses high purity water, i.e. water having no significant ionic content, to produce a membrane suitable for use in filtering ultra pure (18 megohm-cm resistivity) water for use in producing electronic devices. Such a membrane exhibits an advantageously low 'flush-out' time compared to known cationic charge modified microporous membranes and unmodified microporous membranes.

Process for charge modifying a microporous membrane

Charge modified microporous membrane

A depth-type filter cartridge comprises an elongated fluid-conducting core, and a plurality of filter cells mounted generally parallel to one another along the length of the core. Fluid to be filtered passes from the exterior into the interior of the cells through a filter medium, and then from the interior of the cells into the core. Support for the filter cells to prevent distortion or damage when used under extreme conditions is provided by external filter cell separators which coact with the cells and are mounted radially about the core between each pair of adjacent cells.

Filter cartridge including external cell separators

A cellulose-containing separation media for effecting separation of particulate and/or molecular components from a liquid, wherein the cellulose in the separation media is essentially free of non-specific pyrogenic activity as measured by the LAL test. The separation media include filtration media and chromatographic media.

Modified cellulose separation matrix

A novel hydrophilic anionic charge modified microporous filter membrane is provided comprising an organic polymeric microporous filter membrane having a micro-structure throughout the membrane and a modifying amount of an anionic charge modifying agent bound to substantially all of the membrane micro-structure without substantial pore size reduction or pore blockage. The invention is further directed to a process for anionically charge modifying an organic polymeric microporous filter membrane by applying to the membrane the charge modifying agent, preferably, by contacting the membrane with a solution of the charge modifying agent. The anionic modified microporous membrane of this invention may be used for the filtration of fluids, particularly parenteral or biological liquids contaminated with charged particulates, and for plasmapheresis, particularly in the form of hollow fiber tubes. The membrane has low extractables and is sanitizable or sterilizable.

Liquid filtration using an anionic microporous membrane

A chromatography column for effecting chromatographic separation of at least two components of a sample flowing through the column. The column comprises a housing and at least one solid stationary phase within the housing. The stationary phase has chromatographic functionality and is effective for chromatographic separation. Means are provided for radially distributing the sample through the stationary phase and for collecting the sample after the sample has flowed through the stationary phase. The stationary phase comprises:

A cationic charge modified microporous membrane is provided. The membrane comrises a hydrophilic organic polymeric microporous membrane having bonded thereto, through a cross-linking agent, a charge modifying amount of a cationic charge modifying agent. The charge modifying agent is an aliphatic amine or polyamine, preferably tetraethylene pentamine, and the cross-linking agent is an aliphatic polyepoxide having a molecular weight of less than about 500, preferably 1, 4 butanediol diglycidyl ether. The microporous membrane is preferably nylon. The process for applying the charge modifying agent to the membrane, preferably comprises contacting the membrane with an aqueous solution of the charge modifying agent and then contacting the membrane with a substantially aqueous solution of the cross-linking agent. The preferred process uses high purity water, i.e. water having no significant ionic content, to produce a membrane suitable for use in filtering ultra pure (18 megohm-cm resistivity) water for use in producing electronic devices. Such a membrane exhibits an advantageously low 'flush-out' time compared to known cationic charge modified microporous membranes and unmodified microporous membranes.

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Lexington, MA, United States of America

Chaokang Chu