A hollow fiber that generally extends in a longitudinal direction is provided. The hollow fiber comprises a hollow cavity that extends along at least a portion of the fiber in the longitudinal direction. The cavity is defined by an interior wall that is formed from a thermoplastic composition containing a continuous phase that includes a polyolefin matrix polymer and a nanoinclusion additive dispersed within the continuous phase in the form of discrete domains. A porous network is defined in the composition that includes a plurality of nanopores.

A polymeric fiber for use in gas separation is formed from a spin dope which includes solvent and non-solvent materials. The fiber is passed through a quench bath, and then a leach bath, in which the solvent and non-solvent are removed. The quench bath and the leach bath include sets of rollers which transport the fiber through the system. Each set of rollers in the leach bath operates at a speed which is greater than or equal to the speed of the rollers which are immediately upstream. Thus, the fiber is stretched, in different amounts, at the same time that the solvent and non-solvent are being removed, and while the fiber is still wet. The resulting fiber has been found to exhibit superior flux and selectivity properties.

[Problem] The purpose of the present invention is to provide a polyamide hollow fiber membrane having such properties that the transmission of fine particles through the membrane can be prevented effectively, the membrane has an excellent water transmissibility, the entire surface of the membrane has excellent hydrophilicity, and impurities such as metal elements are rarely eluted through the membrane. [Solution] A polyamide hollow fiber membrane produced by a TIPS method under specific production conditions has the following characteristic properties: (1) the contact angle of water on the surface of the membrane is 80? or less; (2) the external pressure water transmissibility of the membrane is 50 L/(m.sup.2.Math.atm.Math.h) or more; and (3) the 50 nm-particles blocking ratio of the membrane is 90% or more.

A low cost, high selectivity asymmetric polyimide/polyethersulfone (PES) blend hollow fiber membrane, a method of making the membrane and its use for a variety of liquid, gas, and vapor separations such as deep desulfurization of gasoline and diesel fuels, ethanol/water separations, pervaporation dehydration of aqueous/organic mixtures, CO.sub.2/CH.sub.4, CO.sub.2/N.sub.2, H.sub.2/CH.sub.4, He/CH.sub.4, O.sub.2/N.sub.2, H.sub.2S/CH.sub.4, olefin/paraffin, iso/normal paraffins separations, and other light gas mixture separations. The polyimide/PES blend hollow fiber membrane is fabricated from a blend of a polyimide polymer and PES and showed surprisingly unique gas separation property with higher selectivities than either the polyimide hollow fiber membrane without PES polymer or the PES hollow fiber membrane without PES polymer for gas separations such as for H.sub.2/CH.sub.4, He/CH.sub.4, H.sub.2S/CH.sub.4, CO.sub.2/CH.sub.4 separations.

The invention relates to extracorporeal blood circuits, and components thereof (e.g., hollow fiber membranes, potted bundles, and blood tubing), including 0.005% to 10% (w/w) surface modifying macromolecule. The extracorporeal blood circuits have an antithrombogenic surface and can be used in hemofiltration, hemodialysis, hemodiafiltration, hemoconcentration, blood oxygenation, and related uses.

Disclosed are a bundle of hollow fiber membranes to improve use efficiency of the hollow fiber membranes and a method of manufacturing the same. The bundle of hollow fiber membranes includes a plurality of yarns to form fluid channels and serve as spacers disposed between the hollow fiber membranes to create a bundle. The method includes spinning including supplying a spinning dope to a nozzle and conducting spinning to form a plurality of hollow fiber membranes, coagulating the hollow fiber membranes formed during spinning, and yarn feeding including inserting a plurality of yarns between the hollow fiber membranes to form a bundle. The method is effective in uniformly distributing a fluid through fluid channels formed between the hollow fiber membranes and maximizes usage efficiency of the hollow fiber membranes.

A hollow fiber porous membrane includes polyethersulfone or polysulfone. The hollow fiber porous membrane has an inner diameter from 300-600 m, a thickness from 70-200 m, a molecular weight cut-off of 10000 or lower, and a plurality of pores having a pore diameter from 0.1-0.5 m throughout an outer surface; and a bulging rate of less than 5%. For 20 or more of the hollow fiber porous membranes, after a membrane thickness in a cross section of each one of the hollow fiber porous membranes in the width direction is measured at randomly selected 10 or more locations, an average membrane thickness is calculated based on 200 or more locations in total, and the bulging rate is calculated by a formula below: Bulging Rate (%)=(location numbers where the membrane thickness as measured exceeded 1.3 times the average membrane thickness)/(membrane thickness measurement numbers)100.

A polymer membrane for water treatment, characterized in comprising a hollow fiber membrane having a self-supporting design composed of the substantially single principal structural material, with an outer diameter of 3.6 mm to 10 mm and a ratio of outer diameter to thickness, SDR, of 3.6 to 34.

One method as described herein relates to making a membrane comprising an uncrosslinked high molecular weight polyimide polymer with a small amount of bulky diamine. Also as described herein is a hollow fiber polymer membrane comprising an uncrosslinked high molecular weight polyimide polymer with a small amount of bulky diamine. The polyimide polymers include monomers comprising dianhydride monomers, diamino monomers without carboxylic acid functional groups, and optionally diamino monomers with carboxylic acid functional groups, wherein 2 to 10 mole % of the diamino monomers are bulky diamino compounds and the ratio of diamino monomers with carboxylic acid functional groups to diamino monomers without carboxylic acid functional groups is 0 to 2:3. These uncrosslinked high molecular weight polyimide polymers with a small amount of bulky diamine are useful in forming polymer membranes with high permeance and good selectivity that are useful for the separation of fluid mixtures.

One method as described herein relates to making a membrane comprising an uncrosslinked high molecular weight, monoesterified polyimide polymer with a small amount of bulky diamine. These uncrosslinked high molecular weight, monoesterified polyimide polymers with a small amount of bulky diamine are useful in forming polymer membranes with high permeance and good selectivity that are useful for the separation of fluid mixtures. Also as described herein is a hollow fiber polymer membrane comprising an uncrosslinked high molecular weight, monoesterified polyimide polymer with a small amount of bulky diamine. The small amount of bulky diamine allows for formation of a membrane comprising the uncrosslinked polymer that exhibits high permeance and good selectivity.