Abstract: The invention provides parylene membrane filters, filter devices and methods of making them and using them in the mechanical separation of cells and particles by size. The provision of parylene membrane filters with high figures of merit and finely controlled hole sizes allows the separation of cells and particles in a variety of biological and other fluids according to sizes.

Abstract: The invention relates to a micro-porous membrane comprising a porous membrane carrier made of a first polymeric material (A) and comprising a second polymeric material (B) intimately divided throughout the porous membrane carrier, wherein the porous membrane carrier comprises a plurality of interconnected polymeric fibers, fibrils, filaments and/or lamellae having a thickness of less than 1 ?m, the porous membrane carrier has an interconnected open porous structure formed by the plurality of interconnected polymeric fibers, fibrils, filaments and/or lamellae and a porosity of at least 50%; and the polymeric material (B) comprises a thermoplastic polycondensation polymer and is present in an amount of at most 30 wt. %, relative to the total weight of (A) and (B).

Abstract: A semipermeable asymmetric hollow fiber membrane is provided, based on a hydrophobic polymer, such as polyethersulfone or polysulfone, and on a hydrophilic polymer, such as PVP. The PVP polymer comprises a high molecular weight component and a low molecular weight component. The membrane has a significantly improved permeability and selectivity, based on its structure, composition, and the method of manufacture of the membrane A process for manufacturing such a membrane by a solvent phase inversion spinning process is also provided.

Abstract: The invention relates to a hollow fiber membrane module comprising polysulfone type selectively permeable hollow fiber membranes which contain a polysulfone-based resin and a hydrophilic polymer as main components, wherein (A) the content of the hydrophilic polymer in the uppermost layer of the inner surface of the hollow fiber membrane is at least 1.1 times larger than the content of the hydrophilic polymer in the proximate layer of the inner surface of the membrane, and (B) the content of the hydrophilic polymer in the uppermost layer of the outer surface of the hollow fiber membrane is at least 1.1 times larger than the content of the hydrophilic polymer in the uppermost layer of the inner surface of the membrane. The hollow fiber membrane module is exposed to a radioactive ray, on condition that the oxygen concentration of an ambient atmosphere around the hollow fiber membrane is from 0.001 to 0.1%, and that the moisture content of the hollow fiber membrane to the weight thereof is from 0.2 to 7 mass %.

Abstract: The invention offers a separation membrane element that can be produced by a method in which a membrane-sealing portion is formed by, first, immersing end portions of hollow-fiber-shaped porous separation membranes in a resinous liquid and, then, curing the resin, that has a feature in that the membrane-sealing portion is formed of a casting resin and pores of the hollow-fiber-shaped porous separation membranes are filled with a pore-filling resin at the portion at which the membranes are in contact with the membrane-sealing portion, so that the casting resin is strongly bonded with the pore-filling resin, and that has the hollow-fiber-shaped porous separation membranes whose basal portions are flexible, so that breakage of the basal portions and leakage of gas or liquid are less likely to occur when in use; a separation membrane element that has a feature in that in the membrane-sealing portion, at least the surface at a side that is to be in contact with a liquid to be treated is formed of a thermosetting f

Abstract: A polyamide membrane and method for making and using the same, including use within a spiral wound module. While many different embodiments are described, one embodiment includes a polyamide membrane including a coating comprising a combination of a polyalkylene oxide compound and a polyacrylamide compound.

Abstract: It is intended to provide a porous hollow fiber membrane for treating blood which suffers from little mechanical damage in the course of production, transfer or handling and shows excellent fractionation properties though it is a thinned polysulfone-based hollow fiber membrane. A porous hollow fiber membrane for treating blood which comprises a polysulfone-based polymer and polyvinylpyrrolidone and has a gradient porous structure with an increase in pore size from the inside to the outside along the membrane thickness direction, characterized in that the porous structure has a membrane thickness of 25 ?m or more but less than 40 ?m, and fibrils having an average diameter of from 100 to 200 ?m are provided in such a manner that the ratio (To/Ti) of the average outside diameter (To) along the membrane thickness direction to the average inside diameter (Ti) is adjusted to not more than 2.

Abstract: A hydrophilic semipermeable hollow-fibre membrane for blood treatment, with an integrally asymmetric structure based on a synthetic polymer. The hollow-fiber membrane possess on its inner surface a separating layer and an adjoining open-pored supporting layer, and has an ultrafiltration rate in albumin solution of 5 to ?25 ml/(h·m2·mmHg). The hollow fiber membrane is free from pore-stabilizing additives and has a maximum sieving coefficient for albumin of 0.005 and a sieving coefficient of cytochrome c that satisfies the equation SCcc?5·10?5·UFRAlb3?0.004·UFRAlb2+0.1081·UFRAlb?0.25.

Abstract: A method for measuring the number of fine particles in ultrapure water includes subjecting the ultrapure water to internal pressure filtration through a hollow fiber membrane having a skin layer capable of trapping the fine particles in the ultrapure water at least on an inner surface thereof, exposing the inner surface of the hollow fiber membrane, and measuring the number of fine particles on the exposed inner surface.

Abstract: The present invention relates to a device for extracorporeal removal of harmful agents from blood or blood components, comprising full length heparin immobilized on a solid substrate by covalent end point attachment. The present invention also relates to a method for extracorporeal removal of a harmful agent from mammalian blood or blood components. The present invention further relates to a process for covalent end point attachment of full length heparin to a solid substrate.

Abstract: A contained liquid membrane contactor includes a perforated center tube, first and second membrane mats each with a first and a second end both being open, four tube sheets affixing the membrane mats to the center tube, a shell sealed to the tube sheets, and two end caps. The first end of the first mat extends a first distance beyond the second end of the second mat. The first end of the first mat is open at the first tube sheet while the first end of the second mat is open at the second tube sheet. The second end of the first mat is between the second and fourth tube sheets and the second end of the second mat is between the first and third tube sheets.

Abstract: A concentrator is used for concentrating a fluid, particularly a plasma component out of blood, for treatment of a patient. The concentrator apparatus includes a main housing defining a centrifuge chamber, that also holds the filter. The concentrator allows viewing of the fluid after centrifuging, with an outlet port positionable at a height corresponding to the level of the fraction of the fluid to be further concentrated. Once the fluid is centrifuged, a portion of the fluid is drawn through the outlet, and then pressured past the filter to further concentrate the fluid using the same vessel as used for centrifuging. The same plunger is preferably used to draw centrifuged fluid from the centrifuge chamber as to pressure the centrifuged fluid past the filter.

Abstract: A process for manufacturing a zeolite membrane by hydrothermal synthesis on the surface of a porous tubular support 3 with both ends open, by adding a reaction solution containing a silica source and an alumina source and the porous tubular support 3 into a lengthwise reaction container 1 longer than the porous tubular support 3 while placing the porous tubular support 3 vertically in the reaction container 1 and substantially apart from the inner surface of the reaction container 1, and immersing the porous tubular support 3 completely in the reaction solution so that the inside of the porous tubular support 3 is filled with the reaction solution; and heating the reaction solution under conditions of leaving the top and bottom ends of the porous tubular support 3 open, and an apparatus using thereof and zeolite tubular separation membranes thus obtained.

Abstract: Provided are methods for fabricating fluid separation devices with precisely-sized, shaped microscopic capillaries that can separate one immiscible fluid from another on the basis of different separation characteristics. In particular, the method comprises the steps of fabricating a first set of capillaries having a first separation characteristic and a second set of capillaries having a second separation characteristic, incorporating one end of all of the capillaries into an inlet face, incorporating the second end of the first set of capillaries into a first outlet face, and incorporating the second end of the second set of capillaries into a second outlet face. Preferably, the first set of capillaries is hydrophillic and the second set of capillaries is hydrophobic.

Abstract: The present invention provides a hollow fiber membrane for treating liquids. When used for a hollow fiber membrane module for refining a fermented liquid such as beer or wine, the hollow fiber membrane exhibits a high filtration performance per unit area thereof, with reduced clogging of the membrane. The membrane performance is sufficiently recovered by washing. The present invention is a hollow fiber membrane for treating liquids, wherein a ratio of Flux 120 to Flux 30 is 0.45 or higher when filtration is performed by supplying a solution having a turbidity of 20 NTU into a hollow fiber membrane having an internal diameter of 500 to 1500 ?m and a membrane thickness of 100 to 500 ?m with a transmembrane pressure of 1.5 bar, the Flux 30 being flux 30 minutes after the start of the filtration, the Flux 120 being flux 120 minutes after the start of the filtration.

Abstract: A composition is formed by blending a vinylidene fluoride resin having a relatively high molecular weight and an improved crystallinity represented by a difference Tm2?Tc of at most 32° C. between an inherent melting point Tm2 and a crystallization temperature Tc of the resin with a plasticizer and a good solvent for vinylidene fluoride resin, and the composition is melt-extruded into a hollow fiber-form. The hollow fiber-form extrudate is then cooled to be solidified from an outside thereof by introduction into cooling medium and subjected to extraction of the plasticizer and stretching, thereby forming a hollow fiber porous membrane of vinylidene fluoride resin characterized by co-presence of crystal oriented portion and crystal non-oriented portion recognizable by X-ray diffraction method.

Abstract: A hollow-fiber membrane assembly having the function of preventing the membrane filaments from cracking, which comprises: hollow-fiber membrane filaments (1), protective film(s) (2) and fastening material (3), wherein the protective film (2) enwraps the outside of the hollow-fiber membrane filament(s) (1) near the end head (5), and a portion of the protective film (2) is immobilized in the fastening material (3), while the rest portion of the protective film (2) outside of the fastening material (3) is left free.

Abstract: The present invention relates to semipermeable membranes with nanotubes dispersed therein, and the methods of preparing the same.

Abstract: According to one aspect of the present invention, a dual stage filtration apparatus includes a cartridge having a first end and an opposing second end and a first filtration stage including a first bundle of first semi-permeable filtering elements and a second filtration stage including a second bundle of second semi-permeable filtering elements. The cartridge has a fluid inlet port for receiving raw unfiltered fluid into the first filtration stage and a fluid outlet port for discharging purified fluid after it has passed through the first and second filtration stages. The apparatus has an intrastage space that receives fluid that has been filtered in the first filtration stage prior to being filtered again in the second filtration stage, and the fluid inlet port is in fluid communication only with the first filtration stage, while the fluid outlet port is in fluid communication only with the second filtration stage.

Abstract: A filtering apparatus having a vessel and a filter made from fluororesin and treated before filtering operation by at least one of adding thermal treatment in gas or liquid and penetrating with fluid composed of hot water or steam at a temperature of less than melting point of the fluororesin.

Abstract: In a hollow fiber membrane flat module according to the present invention, both ends of hollow fiber membrane bundle which are formed by bundling a plurality of hollow fiber membrane as a sheet are fixed to two housing separately by a fixing resin while maintaining an opening condition in an opening end section in the follow fiber membrane. Furthermore, a maximum width in an orthogonal direction to a longitudinal direction of the hollow fiber membrane is no longer than 25 mm in a cross section which is orthogonal to a longitudinal direction of the housings, and a maximum deflection in the housings which are measured according to a method for measuring the deflection according to the present invention is not more than 1% of a distance between the two housings.

Abstract: A hollow fiber membrane made of two coextruded layers A and B, wherein layer B has a non-woven type structure having a mesh size of 0.1 to 10 ?m and layer A has a porous structure. A method for producing a membrane according to the invention and the use thereof is also disclosed.

Abstract: A concentrator is used for concentrating a fluid, particularly a plasma component out of blood, for treatment of a patient. The concentrator apparatus includes a main housing defining a centrifuge chamber, that also holds the filter. The concentrator allows viewing of the fluid after centrifuging, with an outlet port positionable at a height corresponding to the level of the fraction of the fluid to be further concentrated. Once the fluid is centrifuged, a portion of the fluid is drawn through the outlet, and then pressured past the filter to further concentrate the fluid using the same vessel as used for centrifuging. The same plunger is preferably used to draw centrifuged fluid from the centrifuge chamber as to pressure the centrifuged fluid past the filter.

Abstract: A porous multilayered hollow fiber for outer side pressed filtration is made of a multilayer comprising a supporting layer constituted of the thickness of an expanded porous polytetrafluoroethylene tube, and a filtration layer provided on the outer surface of the supporting layer, wherein pores surrounded by fibrous frameworks in the filtration layer are smaller than those of the supporting layer, and the mean of the maximum fibril length (L) of the fibrous frameworks surrounding each pore in the outer surface of the filtration layer is designed to be small such that (X) and (Y) fall within the range on the XY plane, where (X) is a particle diameter of particles captured when the particle trapping ratio is equal to or more than 90% in the case where the filtration is done under an elevated pressure of 0.1 MPa, and (Y) is a value designated as RFL obtained by dividing (L) by (X).

Abstract: A hollow-fiber porous membrane, comprising a hollow fiber-form porous membrane of vinylidene fluoride resin providing: a ratio F (L=200 mm, v=70%)/Pm4 of at least 7×105 (m/day·?m4), wherein the ratio F (L=200 mm, v=70%)/Pm4 denotes a ratio between F (L=200 mm, v=70%) which is a value normalized to a porosity v=70% of a water permeation rate F (100 kPa, L=200 mm) measured at a test length L=200 mm under the conditions of a pressure difference of 100 kPa and a water temperature of 25° C. and a 4-th order value Pm4 of an average pore size Pm. The hollow-fiber porous membrane has an average pore size smaller than before leading to an improved ability of removing fine particles, while suppressing the lowering in water permeability.

Abstract: The present invention discloses a novel method to improve the selectivities of polybenzoxazole (PBO) membranes prepared from aromatic polyimide membranes for gas, vapor, and liquid separations. The PBO membranes that were prepared by thermal treating aromatic polyimide membranes containing between 0.05 and 20 wt-% of a poly(styrene sulfonic acid) polymer. These polymers showed up to 95% improvement in selectivity for CO2/CH4 and H2/CH4 separations compared to PBO membranes prepared from corresponding aromatic polyimide membranes without a poly(styrene sulfonic acid) polymer.

Abstract: The present invention is aimed to fabricate nanoporous anodic oxide ceramic membrane tubes with excellent pore characteristics by anodizing metal tubes located in a cylindrical symmetry with respect to a cathode which itself has a cylindrical symmetry. The membrane tubes may have protruded portions acting as supports and joints. The present invention also deals with stacks and bundles consisted of numbers of the anodic oxide ceramic tubes for filter and dialysis applications.

Abstract: A membrane generally comprises a tubular support, and a polymeric membrane film on the support. The polymeric membrane film comprises three zones cast simultaneously from a single dope. The three zones include an inner zone on the support comprising macro-void pores, an intermediate zone on the inner zone comprising macro-void pores smaller than the macro-void pores of the inner zone, and a skin on the intermediate zone comprising pores of less than 1 micron.

Abstract: The present invention relates to methods and apparatuses for water filtration comprising contacting a water stream with a membrane comprising a polysulfone having structural units of Formula I wherein X is OH, NR1R2, or OR3; R1 and R2 are independently at each occurrence hydrogen, a C1-C5000 aliphatic radical, a C3-C12 cycloaliphatic radical, a C3-C12 aromatic radical, a polypeptide, a combination thereof, or R1 and R2 taken together form a 5- or 6-membered aliphatic ring or a 5-membered aromatic ring; R3 is a C1-C20 aliphatic radical, C3-C12 cycloaliphatic radical, C3-C12 aromatic radical, or a combination thereof; B? and C? are independently at each occurrence a nitro group, C1-C20 aliphatic radical, C3-C12 cycloaliphatic radical, C3-C12 aromatic radical, or a combination thereof; and q and r are independently at each occurrence 0 to 4.

Abstract: A hollow fiber membrane cartridge comprising a bundle of multiple hollow fiber membranes arranged so as to be vertical in an immersion vessel and comprising bond fixing layers capable of bond fixing of the hollow fiber membrane bundle at both ends thereof, wherein the morphology of each of the bond fixing layers is selected from the group consisting of a triangle, a rectangle and a hexagon, and wherein at least an edge of upper side bond fixing layer, the hollow of the hollow fiber membranes opens, and wherein the hollow fiber membrane bundle at a filtration zone side interface of the upper side bond fixing layer is in the form of multiple wisps.

Abstract: A separator assembly is provided comprising a membrane stack assembly comprising a feed carrier layer, a permeate carrier layer, and a membrane layer, and a central core element comprising a concentrate exhaust conduit and a permeate exhaust conduit; wherein the concentrate exhaust conduit and the permeate exhaust conduit are separated by a first portion of the membrane stack assembly; and wherein a second portion of the membrane stack assembly forms a multilayer membrane assembly disposed around the central core element; and wherein the feed carrier layer is in contact with the concentrate exhaust conduit and not in contact with the permeate exhaust conduit; and wherein the permeate carrier layer is in contact with the permeate exhaust conduit and not in contact with the concentrate exhaust conduit; and wherein the permeate carrier layer does not form an outer surface of the separator assembly.

Abstract: A bioreactor is for processing a fluid stream. The bioreactor may include a bioreaction chamber for receiving the fluid stream therethrough, a pair of spaced apart gas header assemblies within the bioreaction chamber for coupling to first and second gases, a first plurality of hollow fiber membranes (HFMs) extending between the pair of gas header assemblies for introducing the first gas into the fluid stream within the bioreaction chamber, and a second plurality of HFMs extending between the pair of gas header assemblies for introducing the second gas into the fluid stream within the bioreaction chamber.

Abstract: A membrane for fluid separation made of a blend of at least a polyimide polymer and a polyimidazole polymer.

Abstract: Membranes comprising functional polyarylether having structural units of formula I are useful for hemodialysis and hemofiltration: wherein X is selected from Br, NR4R5, OOCR6, OR7, NR4CONR5R6, NR4COOR5R6 and combinations thereof; R1, R2 and R3 are independently at each occurrence CH2X, H, halo, cyano, nitro, a C1-C12aliphatic radical, a C3-C12cycloaliphatic radical, a C3-C12aromatic radical or a combination thereof; R4 and R5 are independently H, a C1-10 aliphatic radical, a C3-C12cycloaliphatic radical, a C3-C12 aromatic radical, or a combination thereof; R6 is H, a C2-10 aliphatic radical, a C3-C12 cycloaliphatic radical, a C3-C12 aromatic radical or a combination thereof; R7 is OCH2CH2(OCH2CH2)nOH or OOCCH2(OCH2CH2)nCH3; Z is a direct bond, O, S, SO, SO2, CO, phenylphospinyl oxide, alkenyl, alkynyl, a C1-C12aliphatic radical, a C3-C12cycloaliphatic radical, a C3-C12 aromatic radical or a combination thereof; a, b, and c are independently 1 or 2; and m, n and p are independently 0 or 1.

Abstract: A process for manufacturing of an asymmetric hollow fibre membrane, comprising the steps of extruding a polymer solution through the outer ring slit of a hollow fibre spinning nozzle, simultaneously extruding a centre fluid through the inner bore of the hollow fibre spinning nozzle, into a precipitation bath, whereby the polymer solution contains 10 to 26 wt-% of polysulfone (PSU), polyethersulfone (PES) or polyarylethersulfone (PAES), 8 to 15 wt-% polyvinylpyrrolidone (PVP), 55 to 75 wt-% N-alkyl-2-pyrrolidone (NAP) and 3 to 9 wt-% w ater the centre fluid contains 70 to 90 wt-% N-alkyl-2-pyrrolidone (NAP) and 10 to 30 wt-% water, and the precipitation bath contains 0 to 20 wt-% N-alkyl-2-pyrrolidone (NAP) and 80 to 100 wt-% water.

Abstract: A hollow fiber membrane module with a fixed structure comprises: a bearing shell (7), an inlet (8), a concentrated water outlet (10), a produced water outlet (9), a central tube (1) and hollow fiber membranes (6), in which the hollow fiber membranes (6), the central tube (1) and the bearing shell (7) are fixed together, the inlet (8) is located at one end of the hollow fiber membranes (6), the concentrated water outlet (10) is located at the other end of the hollow fiber membranes (6), the produced water outlet(s) (9) is(are) located at one end or both ends of the central tube (1), and there are small holes drilled on the side wall of the central tube (1). The module also comprises at least one separate fixed ring(s) (2) for fixing the hollow fiber membranes (6), with the separate fixed ring(s) (2) fixed on the central tube (1) and the hollow fiber membranes (6) arranged in parallel through the separate fixed ring(s) (2).

Abstract: A method is provided for forming zeolite membranes in internal surfaces of a plurality of conduits in a cylindrical porous ceramic monolith, the conduits extending from one end of the monolith to the other, said method including a step of: flowing a pre-treatment liquid including a zeolite initiating agent into the conduits; causing at least part of a carrier liquid component of the treatment liquid to flow from the conduits into and through the body of the monolith to the exterior; and causing zeolite crystals to be deposited in the porous internal surfaces of the conduits as the carrier liquid component flows into the monolith.

Abstract: The present invention relates to a method of producing a hollow fiber membrane bundle having an end fixed with a casting material wherein the ends of hollow fiber membranes are fixed with the casting material in a condition that an insert is placed inside a hollow fiber membrane bundle at a position inner than a region where a fixing portion is formed, and then the insert is removed from the inside of the hollow fiber membrane bundle; and relates to a method of producing a hollow fiber membrane filter element through this method. The hollow fiber membrane bundle produced by the method of the present invention can be used in various types of filtration treatment such as external pressure filtration.

Abstract: The present invention provides a polysulfone type hollow fiber membrane which is reliable in safety and stability of performance and is easily incorporated into a module, and thus can be suitably used in a highly water permeable blood purifier for use in a therapy of chronic renal failure. The present invention relates to a polysulfone type selectively permeable hollow fiber membrane comprising a polysulfone type resin and a hydrophilic polymer as main components, and characterized in that (A) the content of the hydrophilic polymer in the uppermost layer of a surface of the polysulfone type hollow fiber membrane on the blood-contacting side is at least 1.1 times larger than the content of the hydrophilic polymer in the proximate layer of the surface on the blood-contacting side, and (B) the content of the hydrophilic polymer in the uppermost layer of the other surface of the polysulfone type hollow fiber membrane, i.e., the reverse side of the surface on the blood-contacting side, is at least 1.

Abstract: Disclosed herein is a hollow fiber membrane for feeding a mixture into the hollow space thereof, in which the mixture to be separated is fed into the hollow space of the hollow fiber membrane and allowed to permeate through a porous membrane comprising an active layer. The hollow fiber membrane is manufactured by forming a tubular active layer having a hollow space and making a polymer fiber braid, a metal wire braid or a braid consisting of a mixture of polymer fiber with metal wire, directly on the outer surface of the tubular layer, such that the active layer can be prevented from being expanded if a high-temperature, high-pressure mixture is fed into the hollow space.

Abstract: A multipolymeric mixture is provided that includes a hydrophobic polymer, two different grades of a water-soluble polymer, water as non-solvent and a solvent suitable for all polymers involved. The dissolved hydrophobic polymer has the affinity to enmesh the water-soluble polymers to form a clear and viscous dope. Water-soluble polymers contribute to the pore formation process and hydrophilicity of the finally coagulated membrane according to the makeup of their molecular weight distribution. Water as a non-solvent takes the dope very near towards unstable zone, which helps in speeding up the membrane formation process in a diffusion induced phase inversion technique. The dope is then spun through a concentric orifice spinneret and solidified by passing it through a coagulation bath to form hollow fiber asymmetric membranes of ultra filtration grade with superior water permeability and separation characters even at higher feed turbidity.

Abstract: An apparatus and method for treatment of water borne oxidized contaminants, using hydrogen as an electron donor for denitrification and reduction of other oxidized contaminants. Preliminary results reported here show that a biofilm of autotrophic denitrifiers accumulates rapidly in the wastewater setting, the MBfR can drive NO3? concentrations below 1 mgN/L, and the H2 pressure controls the NO3? flux.

Abstract: Porous polymeric membranes including HALAR® (poly(ethylene chlorotrifluoroethylene)) and related compounds and the methods of production thereof which avoid the use of toxic solvents. Preferred solvents, coating agents and pore forming agents are citric acid ethyl ester or glycerol triacetate. The membranes may be in the form of a hollow fiber or flat sheet, and may include other agents to modify the properties of the membranes, such as the hydrophilic/hydrophilic balance. Leachable agents may also be incorporated into the membranes.

Abstract: Disclosed is a hollow fiber that includes a hollow positioned at the center of the hollow fiber, macropores positioned at adjacent to the hollow, and mesopores and picopores positioned at adjacent to macropores, and the picopores are three dimensionally connected to each other to form a three dimensional network structure. The hollow fiber includes a polymer derived from polyamic acid, and the polyamic acid includes a repeating unit obtained from aromatic diamine including at least one ortho-positioned functional group with respect to an amine group and dianhydride.

Abstract: Problems: To provide a polyvinylidene fluoride microporous membrane which has high water permeability and separation performance and is excellent in mechanical and chemical strength; and a process for producing the film. Means for Solving Problems: An anisotropic polyvinylidene fluoride hollow fiber microporous membrane characterized in that the porosity of the cross-sectional bulk layer is higher than the membrane surface porosity of the outer layer and that in the cross section of the membrane, the dense microstructure of the outer surface changes substantially discontinuously into the coarse structure of the bulk layer.

Abstract: A process for manufacturing of an asymmetric hollow fibre membrane, comprising the steps of extruding a polymer solution through the outer ring slit of a hollow fibre spinning nozzle, simultaneously extruding a centre fluid through the inner bore of the hollow fibre spinning nozzle, into a precipitation bath, whereby the polymer solution contains 10 to 26 wt-% of polysulfone (PSU), polyethersulfone (PES) or polyarylethersulfone (PAES), 8 to 15 wt-% polyvinylpyrrolidone (PVP) and 60 to 80 wt-% N-alkyl-2-pyrrolidone (NAP), the centre fluid contains 60 to 70 wt-% N-alkyl-2-pyrrolidone (NAP) and 30 to 40 wt-% water, and the precipitation bath contains 70 to 82 wt-% N-alkyl-2-pyrrolidone (NAP) and 18 to 30 wt-% water.

Abstract: [Purpose] To provide a blood purifier which has high levels of blood compatibility, performance-retaining property when in contact with blood, and safety, and which shows an excellent water permeability-exhibiting rate after a priming treatment and has high reliability in long-term storage.

Abstract: The membrane module according to the invention is characterized in that it has concrete flanges. This membrane module is made by first sealing a bundle of ceramic fiber membranes at one end using a viscous sealant and then pressing it into a fluid mass of concrete in a mould. After the mass of concrete has hardened the process is repeated with the other end of the bundle. Finally the ends of the fiber membranes are opened by sawing off a slice of the flanges.

Abstract: A device for removing bacterial lipopolysaccharides and lipoteichoic acids from blood or plasma in an extracorporeal perfusion system contains, in a housing that can be incorporated into the perfusion system, a hollow fiber material that is suitable for the selective removal of bacterial lipopolysaccharides and lipoteichoic acids, the device being arranged in such a way that the blood or plasma entering through a first opening of the housing must pass through the hollow fiber material before it leaves through a second opening of the housing and is directed to the rest of the perfusion circuit.

Abstract: A hollow-fiber porous membrane comprising a hollow-fiber form of vinylidene fluoride resin and satisfying the following properties (A) and (B), is provided as a hollow-fiber porous membrane of vinylidene fluoride resin having an average pore size and a further uniform pore size distribution (A) and a large water permeation rate regardless of good efficiency of blocking minute particles (bacteria) (B), as represented by: (A) a ratio Pmax (1 m)/Pm of at most 4.0 between a maximum pore size Pmax (1 m) measured at a test length of 1 m according to the bubble point method and an average pore size Pm of 0.05-0.