Abstract: The invention is directed broadly to microporous films prepared from immiscible blends of at least two components, preferably polymers, which are produced via melt processing, a film formed therefrom, for example by extrusion and post-film-forming treatments comprising uniaxial or biaxial cold-stretching and hot-stretching. The films have a three-dimensional reticulated or interconnected network of microcracks or crazing throughout the film, extending from one surface of the film to the other, providing a stable porosity and pore size useful for a variety of filtration and other applications.

Abstract: Blood separation media include a non-woven web of fibrillated and non-fibrillated synthetic staple fibers. The fibrillated synthetic staple fibers will most preferably have a Canadian Standard Freeness (CSF) of less than about 300 mL, whereas the non-fibrillated synthetic staple fibers have a CSF of greater than about 700 mL. Preferably, the fibrillated synthetic staple fibers are present in an amount between about 20 to 90 wt. %, and the non-fibrillated synthetic staple fibers are present in an amount between about 10 to about 80 wt. %. The fibrillated and non-fibrillated synthetic staple fibers may be formed of the same, or different, polymeric material, such as polyesters, polypropylenes, polyethylenes, poyacrylonitriles, and polyamides. Especially preferred blood separation media will comprise a blend of fibrillated acrylic fibers, and a mixture of non-fibrillated nylon and polyester fibers, wherein the ratio of nylon and polyester fibers in the mixture thereof is between about 1:4 to about 1:2.

Abstract: Filters for removing particulate and gaseous organic and inorganic materials from a fluid stream are disclosed. The filter may contain a polymer matrix and optional sequestering agents. Methods of making the filters are also disclosed. Methods of using the filters to remove one or more materials from a fluid stream, such as an air stream, are also disclosed.

Abstract: The present invention relates to filtration media having both hydrophobic (water-repellent) properties. The filtration media are produced using a fluorothermoplastic material, such as a terpolymer of tetrafluoroethylene, vinylidene fluoride, and hexafluoropropylene. The invention also relates to methods of preparing such filtration media using casting solution phase inversion.

Abstract: The present invention relates to a facilitated transport membrane for separation of alkene hydrocarbons from hydrocarbon mixtures, comprising a porous support and a solid polymer electrolyte consisting of a transition metal salt and a polymer having phthalic structure, in which the electrolyte is in solid state at its operating temperature. The facilitated transport membrane is prepared by forming a solid polymer electrolyte consisting of a transition metal salt and a polymer on a porous support. The transition metal salt can selectively and reversibly form a complex with alkene hydrocarbons and the polymer can dissociate the transition metal salt. In particular, the polymer matrix allows the transition metal salt to be well dissociated because it has a phthalic structure capable of being coordinated to a transition metal ion.

Abstract: The present invention relates to a facilitated transport membrane for separation of alkene hydrocarbons from hydrocarbon mixtures, comprising a porous supported membrane and a transition metal salt-polymer membrane consisting of a transition metal and a polymer, in which the transition metal salt does not chemically react with the polymer but physically dispersed within the polymer which has no functional group capable of forming a complex with the transition metal salt. The facilitated transport membrane according to the present invention is prepared by forming a solid transition metal salt-polymer membrane consisting of a transition metal salt and a polymer capable of dispersing the transition metal salt on the molecular scale; and coating the solid membrane on a porous supported membrane with good permeance and superior mechanical strength.

Abstract: High flux porous hollow fiber membranes are produced from perfluorinated thermoplastic polymers by extruding a heated solution of the polymer having a lower critical solution temperature directly into a cooling bath to form the porous membrane by liquid-liquid phase separation. Extrusion can be conducted either vertically or horizontally.

Abstract: High flux porous hollow fiber membranes are produced from perfluorinated thermoplastic polymers by extruding heated solution of the polymer having a lower critical solution temperature directly into a cooling bath to form the porous membrane by liquid-liquid phase separation. Extrusion can be conducted either vertically or horizontally.

Abstract: The present invention relates to a super water-repellent organic/inorganic composite material, more particularly to a new-concept super water-repellent organic/inorganic composite material with superior separation property having skin layer chemically immobilized with functional polymer on the porous inorganic support surface with fractal surface structure and pores of nanometers to micrometers, using grafting-from surface polymerization method.

Abstract: Breathable, flushable, porous films and articles made therewith and a process for making these films. The present invention is directed to composites comprising a polymer that is water-soluble or water-degradable and a filler. The films are made by extruding the composite materials into a precursor film and, preferably, stretching the precursor film to achieve the desired breathability and water-dispersibility of the finished film. In one embodiment, the composition of the invention comprises a polymer of ethylene oxide and a filler such as calcium carbonate.

Abstract: The present invention provides integral porous membranes comprising an amorphous halopolymer, as well as processes for preparing the membranes, and devices comprising the membranes. An example of an amorphous halopolymer is a copolymer of tetrafluoroethylene and perfluoro-2,2-dimethyl-1,3-dioxole.

Abstract: Water-desalination and/or water purification devices. Alternatively, devices that are implantable in animal bodies, possibly configured as self-inflating spinal disc prostheses. The devices include specified types of water-absorbing solute encapsulated by non-porous, water-permeable polymer membranes having specified properties. Also, methods of using the devices in biomedical applications or water treatment.

Abstract: A filter material comprising at least one nonheatsealable ply and at least one heatsealable ply which comprises fibers of synthetic material and contains an adhesion promoter, and also processes for producing same.

Abstract: A microporous PVDF membrane is rendered hydrophilic without making it brittle or lowering its heat resistance by exposing the membrane to a plasma under controlled conditions. Specifically, a microporous PVDF membrane is first coated with an appropriate monomer. After the monomer dries, the membrane is exposed to the plasma. Any remaining uncured monomer on the membrane is removed. Thereafter, the membrane is pleated and incorporated in a filter cartridge.

Abstract: The invention provides a disposable filter, including a filtering bag with an opening, the bag being made of a non-woven, synthetic material having filtering perforations, and a substantially flat, stretchable band extending along the periphery of the opening, facilitating the easy attachment and detachment of the bag within a liquid filtering apparatus.

Abstract: A method of treating a membrane comprises the steps of providing a membrane with surfaces that define a plurality of pores extending through the membrane. Providing a dispersion of oleophobic fluoropolymer solids. Stabilizing the dispersion with a stabilizing agent. Diluting the dispersion with a wetting agent. Wetting surfaces which define the pores in the membrane with the diluted and stabilized dispersion. Removing the wetting agent and the stabilizing agent from the membrane. Coalescing the oleophobic fluoropolymer solids of the dispersion on surfaces that define pores in the membrane. A composite membrane comprises a porous membrane having a plurality of interconnecting pores extending through the membrane and made from a material which tends to absorb oils and certain contaminating surfactants. A coating is disposed on surfaces of the nodes and fibrils defining the interconnecting passages in the membrane.

Abstract: The present invention provides a microporous polyolefin membrane of high permeability and novel structure, and also provides a method of producing the same, wherein its average pore size is gradually decreases from at least one membrane surface towards its center. The method of producing the microporous polyolefin membrane comprises the steps of extruding the solution, composed of 10 to 50 weight % of (A) a polyolefin having a weight-average molecular weight of 5×105 or more or (B) a composition containing this polyolefin and 50 to 90 weight % of a solvent, into a gel-like formed article and removing the solvent therefrom, wherein a treatment step with a hot solvent is incorporated.

Abstract: A charge mosaic membrane having excellent selective permeability comprises a cationic polymer component, an anionic polymer component and a matrix component. Both of the cationic polymer component and the anionic polymer component are crosslinked particulate polymers. The matrix component is at least one polymer selected from a polysulfone resin, a polyarylate resin, a polyamide resin, a polyimide resin, a polyamideimide resin, a polyurethane resin, a fluorinated resin or a silicone resin. The charge mosaic membrane can be easily produced by conducting formation of the membrane by using a composition in which the cationic polymer component and the anionic polymer component are both dispersed in a solution of the matrix component in an organic solvent.

Abstract: This invention relates to a hollow fiber membrane module to be used in industrial fields such as the semiconductor industry, food processing industry, pharmaceutical industry, and medical industry, and to a method for the production thereof. Permselective hollow fiber membranes having rigidity are cheese-wound in a plurality of layers, thereby forming a hollow fiber membrane bundle. One terminal part of this hollow fiber membrane bundle together with a case is adhered and solidified with a thermally molten mass of thermoplastic resin, thereby forming a solidified part. This solidified part is cut to form a sealed part serving to open terminal parts of the hollow fiber membranes.

Abstract: The present invention relates to laminated membranes formed by multi-layer processing techniques including alternating layers of thermoplastic urethane and a copolymer of ethylene and vinyl alcohol. The membranes are characterized in that hydrogen bonds are formed between the layers of thermoplastic urethane and the copolymer of ethylene and vinyl alcohol. The membranes are characterized in that hydrogen bonds are formed between the layers of thermoplastic urethane and the copolymer of ethylene and vinyl alcohol.

Abstract: A hydrophilic membrane that includes a hydrophobic polymer and a water-soluble polymer-metal complex is provided. This membrane is made by heating a mixture of a hydrophobic polymer, a metal compound, and a water-soluble polymer. The water-soluble polymer forms complexes with the metal compound and homogeneously entangles with the dissolved hydrophobic polymer to form a viscous dope. The dope is extruded through an annular orifice to form a hollow fiber. The fiber is put in an environment having a controlled humidity so that it becomes partially solidified, and then, the fiber is put in a coagulation bath. The hollow fiber is formed by phase inversion in the coagulation bath and is collected using a take-up wheel that is partially immersed in a leaching bath.

Abstract: Disclosed herein is a medium for analyzing a substance in a mixture and method of making and using. In particular, the medium comprises a network of at least one polymeric fiber having a derivatized polymeric surface which allows immobilization of at least one selective binding agent thereon in a highly dispersed and randomly spaced orientation which forms a tortuous interstitial path for passage of the mixture therethrough. The substance may be a chemical substance or a biological substance. Also disclosed are assay matrices, assay systems and kits comprising the medium.

Abstract: An article, such as a filter or film, has a treated laminate with an expanded PTFE membrane and a porous support scrim. The treated laminate is formed by contacting a laminate having an expanded PTFE membrane and a porous support scrim with an oleophobic treatment agent dissolved in an organic solvent. The oleophobic treatment agent is deposited onto the expanded PTFE membrane and porous support scrim as the organic solvent is removed. The oleophobic treatment agent is typically a fluoropolymer. The article can be used, for example, as a filter over a port in a housing of an electronics or other device.

Abstract: A method for membrane filtration purification of suspended water, comprising filtering the suspended water under an external pressure through a porous hollow fiber membrane comprising a polyolefin, a copolymer of olefin and halogenated olefin, halogenated polyolefin or a mixture thereof and having an open area ratio in an outer surface of not less than 20% and a pore diameter in a minimum pore diameter layer of not smaller than 0.03 &mgr;m and not larger than 1 &mgr;m.

Abstract: A method of raising the concentration of a liquid mixture utilizes osmotic distillation to transfer a volatile liquid component from the mixture in contact with one side of a nonporous, preferably high free volume, gas permeable membrane to a strip solution in contact with the other side of the membrane. Due to its nonporous nature the gas permeable membrane resists penetration and wetting by oily components that may be present in the feed mixture. Similarly, occlusion of the membrane by solids is resisted. Preferably, an amorphous copolymer of perfluoro-2,2-dimethyl-1,3-dioxole is useful for the gas permeable membrane. Osmotic distillation utilizing such high free volume, nonporous gas permeable membranes can concentrate difficult liquid mixtures such as pulpy fruit juices and especially, limonene-containing juices, for example, orange juice. The process can be operated at high flux for long durations between membrane cleanings.

Abstract: A breathable, stretch-thinned barrier film having improved strength, processability and/or breathability is formed from a mixture of a thermoplastic polymer and cavated filler particles such as cyclodextrin. The cavated filler particles provide the film with enhanced breathability to water vapor due to their ring-like, conical, cylindrical or otherwise hollow molecular structure, yet the film remains substantially impermeable to aqueous liquids. The enhanced breathability occasioned by the cavated particles permits the use of relatively low filler levels and correspondingly high polymer levels, thereby enhancing the film strength. The filler may melt during extrusion of the molten polymer into a film, facilitating smooth processing, and re-crystallize into particles after the film is formed and cooled.

Abstract: The present invention relates to cationically charge-modified membranes and methods of preparing such membranes. In one major aspect of the invention, the membranes are hydrophobic membranes that are treated with one or more polymeric wetting agents to render the membranes substantially hydrophilic, followed by treatment with one or more charge-modifying agents, the agents causing the membranes to possess a fixed formal positive charge. In another major aspect of the invention, a cationic membrane is formed from casting in a film a mixed polymer solution comprising a sulfone polymer and a copolymer of vinylpyrrolidone and a cationic imidazolinium compound, and quenching the film in an aqueous bath to produce a coagulated membrane. The membrane can be further cationically charge-modified with one or more charge-modifying agents.

Abstract: The present invention relates to an asymmetric porous polytetrafluoroethylene membrane comprising a dense skin layer and a continuously foamed porous layer, (1) the dense skin layer having a surface roughness Ra of 20 to 165 nm; (2) the dense skin layer having a contact angle for water of 120 to 135°; (3) the porous layer having a maximum pore diameter of 0.03 to 1.0 &mgr;m; and (4) the membrane having a total porosity of 20 to 70%. The asymmetric porous PTFE membrane has an ability to separate each liquid component from a liquid-liquid homogeneous mixture in addition to known properties such as water permeability resistance, gas permeability, sealing property and electric property, wherein change of these properties over time is small.

Abstract: A multi-layer polymer electrolyte membrane having a polymer electrolyte layer and a porous polymer electrolyte layer with three dimensional network pores on the former polymer electrolyte layer is provided. The polymer electrolyte layer can be provided on both sides of the porous polymer electrolyte layer. An electrochemical apparatus and a solid polymer electrolyte type fuel cell made of the multi-layer polymer electrolyte membrane can be provided. Further, a solid polymer electrolyte type fuel cell having the multi-layer polymer electrolyte membrane can be provided. Further, a process for the preparation of the multi-layer polymer electrolyte membrane can be provided.

Abstract: A pore plugging material, for pH dependent membrane diffusion, in which cyclic olefins having phosphazene-functional moieties provide predictable erosion properties when used to plug pores in separation barriers and other porous membranes. Specific properties of the polymers are dependent on several factors, including molecular weight and identity of side groups attached to the phosphazene moiety. However, as a class, phosphazene-functional cyclic olefins provide both predictable erodibility and uniformly benign hydrolysis products and are, therefore, uniquely suitable as pore plugging polymers for separation barriers and membranes of all kinds. The invention, therefore, embraces the provision of a pH-sensitive erodible pore plugging material for pores in separation barriers and membranes of all kinds.

Abstract: An improved sintered porous thermoplastic filter incorporating a second thermoplastic treated with a non-leaching antimicrobial agent for the purification of liquids. The method of making the filter is also disclosed.

Abstract: Cast semi-permeable membranes made from synthetic polymer used in reverse osmosis, ultrafiltration and microfiltration are treated with a non-leaching antimicrobial agent to prevent its bio-fouling and bacterial breakthrough. The semi-permeable membranes include a polymeric material and a non-leaching antimicrobial agent that is incorporated into and homogeneously distributed throughout the polymeric material. The polymeric material, in the case of one membrane, may be cellulose acetate. In the case of thin film composite polyamide membranes, the antimicrobial agent is incorporated in a microporous polysulfone layer that is sandwiched between a reinforcing fabric and an ultrathin polyamide material. The invention also includes a treatment of flat and hollow fiber semipermeable membranes made with polysulfones and polyvinylidene fluoride.

Abstract: A three zone, reinforced, continuous, geometrically symmetrical microporous membrane including a porous support material encapsulated within a middle zone disposed between an upper zone and a lower zone wherein at least one of the three zones has a pore size at least about twenty (20%) percent different than the pore size of the other two zones is disclosed. Apparatus and methods for fabricating three zone reinforced, continuous, geometrically symmetrical, microporous membrane are also disclosed.

Abstract: The invention concerns a filter material characterized in that it is impregnated with an amphiphilic substance or with a hydrophilic and a hydrophobic substance to control the water wettability and water absorption.

Abstract: A membrane which can be used in membrane filtration processes and which has a reduced tendency to fouling is a polysulphone or a plyether sulphone and a polyethylene oxide/polypropylene oxide substituted diamine and can be made by a phase inversion process in the presence of pore modifying agents such as an alcohol, glycerol or glycol to give a membrane which has a pore size of 0.1&mgr; to 1 micron and is hydrophilic.

Abstract: This invention provides a one-piece multilayer article for use in solid phase extraction that includes at least two porous support layers and a solid phase extraction medium, wherein the porous support layers are thermo-mechanically attached at at least one thermo-mechanical attachment site. At least one of the porous support layers can be a prefilter layer.

Abstract: The present invention provides a gas-permeable hollow fiber membrane having an inner diameter of 50 to 500 &mgr;m and a membrane thickness of 10 to 150 &mgr;m, which is preferably a composite hollow fiber membrane having a three-layer structure consisting of a nonporous layer having porous layers disposed on both sides thereof. Dissolved gases present in an ink can be removed by passing the ink through the bores of hollow fibers comprising such a hollow fiber membrane, and evacuating the outer surface side of the hollow fibers. This method makes it possible not only to degas inks with a slight pressure loss, but also to degas inks stably even if pressure changes occur during degassing.

Abstract: Asymmetric hydrophilic polymeric membranes are disclosed wherein the asymmetry between the pore diameters of the first and second membrane faces is at least about 2:1, and wherein the membrane comprises a hydrophobic polymer to which hydrophilic moieties have been covalently bonded. A method of preparing such membranes is provided, wherein an asymmetric hydrophobic polymeric membrane is immersed in a solution comprising a solvent, a free radical polymerization initiator, and a monomer having hydrophilic moieties, then exposed to an energy source, whereby the monomer is covalently bonded to the hydrophobic polymer of the membrane. A method of rendering a hydrophobic polymeric substrate permanently hydrophilic is disclosed, wherein a hydrophobic polymeric substrate is immersed in a solution of monomer and free radical polymerization initiator in an alkylene glycol solvent, then exposed to an energy source so as to covalently bond the hydrophilic monomer to the substrate.

Abstract: A method is provided for producing porous hydrophilic materials whereby nonporous materials are subjected to ester hydrolysis to generate site-specific perforations. Processes for separating aqueous phase from organic and aqueous mixtures utilizing the invented materials also are provided.

Abstract: The present invention provides a gas-permeable hollow fiber membrane having an inner diameter of 50 to 500 &mgr;m, which is preferably a composite hollow fiber membrane having a three-layer structure consisting of a nonporous layer having porous layers disposed on both sides thereof. This membrane can be used to remove dissolved gases present in an ink.

Abstract: A novel process for the regeneration of PTMSP membranes is disclosed. The regeneration process includes washing a fouled PTMSP membrane with a solution containing at least about 50% butanol in water for a time sufficient to increase the flux and/or selectivity of the membrane. This regeneration process with a butanol containing solution significantly improves both the flux and selectivity of the PTMSP membrane and can regenerate the flux of the PTMSP membrane to the level of a previously unused membrane.

Abstract: Process for producing hydrophobic polyolefinic membranes for gas exchange via thermally induced liquid-liquid phase separation is disclosed. A solution of at least one polyolefin in a solvent system, of a compound A and a compound B having a viscosity less than 60 mPa s, is extruded to form a shaped object. The compound A is a solvent and compound B preferably a non-solvent of the polymer, and the boiling point of compound A is at least 50° C. higher than that of compound B. After the shaped object leaves the die, at least one surface thereof is subjected to an atmosphere promoting evaporation of compound B, and the shaped object is subsequently cooled until the phase separation and solidification of the high-polymer-content phase take place.

Abstract: A method for removing iron-containing contaminants from condensate from a power generating plant includes passing the condensate through a plurality of pleated filter elements contained within a housing, including direct the condensate through a pleated hydrophilic film comprising ultra-high molecular weight polyethylene. The invention is capable of removing fine particulate matter and provides long filtration cycles between backwashing.

Abstract: Process for producing an integrally asymmetrical hydrophobic polyolefinic membrane with a sponge-like, open-pored, microporous support structure and a separation layer with a denser structure compared to the support structure, via a thermally induced liquid-liquid phase separation process. A solution of at least one polyolefin in a solvent system consisting of a compound A and a compound B is extruded to form a shaped object. Compound A is a weak solvent and compound B a non-solvent for the polymer. After leaving the die, the shaped object is cooled using a solid or liquid cooling medium that does not dissolve or react chemically with the polymer at temperatures up to the die temperature, until the phase separation and solidification of the high-polymer-content phase take place.

Abstract: A porous membrane product is provided which is formed from a porous membrane substrate having its surface completely modified with a perfluorocarbon copolymer composition. The porous membrane product has substantially the same permeability as the porous membrane substrate.

Abstract: An apparatus providing for metal ion/nitrate entrapment comprises a chemically activated, microfiltration, composite polymer and silica-based membrane including a polyamino acid attached thereto through reaction of a terminal amine group of the polyamino acid with the membrane. A method for preparing such a chemically activated or polyamino acid functionalized membrane includes the steps of permeating the silica-based membrane with a solution of silane and a solvent so as to react methoxy groups of the silane with silanol groups of the membrane to incorporate epoxide groups and attaching a polyamino acid to the membrane by reacting a terminal amine group of the polyamino acid with one of the epoxide groups on the membrane.

Abstract: A non-cracking hydrophilic polyether sulfone membrane is prepared by (a) directly coating the entire surface of a hydrophobic polyethersulfone membrane with an aqueous solution of a polyalkylene oxide polymer and at least one polyfunctional monomer, and (b) polymerizing the monomer over the entire surface of the membrane under conditions which cause the resulting polymer to attach to the polyethersulfone membrane and the polyethylene oxide to form a non-extractable surface which does not crack when the membrane is folded to form a pleated cartridge.

Abstract: A hollow fiber membrane made of an ethylene-vinyl alcohol polymer, comprising a dense layer existing in the inner surface and a porous layer existing in the layer other than the dense layer, wherein the hollow fiber membrane has a porosity of 60 to 90%, an overall mass transfer coefficient for myoglobin in a water-based system of not less than 0.003 cm/min., and a rejection rate for albumin in a bovine blood system of not less than 97%. The EVA hollow fiber membrane is useful for hemopurification membranes such as hemodialysis membranes, hemodiafiltration membranes, hemofiltration membranes and continuous hemofiltration membranes, and a process for producing the same.

Abstract: A porous membrane product is provided which is formed from a porous membrane substrate having its surface completely modified with a perfluorocarbon copolymer composition. The porous membrane product has substantially the same permeability as the porous membrane substrate.

Abstract: A composite membrane is provided which includes a base material and an ion exchange resin. The base material has a microstructure characterized by nodes interconnected by fibrils, or a microstructure characterized by fibrils with no nodes present. The ion exchange resin substantially impregnates the membrane such that the membrane is essentially air impermeable.