A hollow-fiber membrane. The hollow-fiber membrane is made from a polymeric blend comprising an aromatic sulfone polymer and polyoxazoline; wherein the hollow-fiber membrane comprises an inner surface facing towards its lumen, an outer surface facing outwards and an intermediate wall having a wall thickness; wherein the hollow-fiber membrane is an integrally asymmetric, permeable hollow-fiber membrane.

A porous membrane has a thickness of 150 m or greater. The pore diameters of a first surface are smaller than the pore diameters of a second surface. The average value of the pore diameters of the first surface is 60 nm or less, and the coefficient of variation of the pore diameters is 10% or greater and 50% or less.

A conventional media filter such as a gravity sand filter is converted into a membrane filter. The media is removed and replaced by immersed membrane modules. Transmembrane pressure is created by a static head pressure differential, without a suction pump, thereby creating a membrane gravity filter (MGF). Membrane permeate passes through a bed of adsorption media optionally located in a tank with the membrane modules. The membranes are backwashed periodically with permeate, which bypasses the adsorption media as it returns to the membrane module.

A gas separation membrane comprising the following layers: (i) a porous support layer; and (ii) a discriminating layer comprising groups of the Formula (1): M(O).sub.x, wherein: M is a metal or metalloid atom; O is an oxygen atom; and x has a value of at least 4; optionally (iii) a layer which comprises a fluorinated polymer; and optionally (iv) optionally a protective layer; wherein: (a) the porous support layer (i) comprises less than 10 mg/m.sup.2 of monovalent metal ions; (b) the discriminating layer (ii) comprises a surface comprising at least 10 atomic % of M of Formula (1) groups, wherein M is as hereinbefore defined; and (c) when layer (iii) is present, layer (ii) is located between layers (i) and (iii).

A functional polymer membrane of the present invention contains a polymer containing at least a structure represented by the following Formula (I), a method for producing the membrane, and an ion exchange apparatus: ##STR00001##
wherein R.sup.1 and R.sup.2 each represent a hydrogen atom or an alkyl group; R.sup.3 to R.sup.6 each represent a substituent; R.sup.3 to R.sup.6 may be bonded to each other and form a ring; A.sup.1 to A.sup.4 each represent a single bond or a divalent linking group; M.sup.1 represents a hydrogen ion, an organic base ion, or a metal ion; J.sup.1 represents a single bond, O, S, SO.sub.2, CO, CR.sup.8R.sup.9, or an alkenylene group, and R.sup.8 and R.sup.9 each represent a hydrogen atom, an alkyl group, or a halogen atom; and k1, k2, k3, k4, n1, n2, m1, m2, p, and q each represent a particular integer.

The invention is directed to preparation of hollow fiber membrane devices that exhibit improved durability and mechanical strength in air separation operations such as generation of nitrogen enriched air on board aircraft. In particular the invention provides for preparation of hollow fiber membrane modules with terminal tubesheets of superior mechanical properties and improved long term durability in air separation operations.

The present invention relates to a process for preparing an asymmetric integrally skinned membrane for the separation of at least one solute from a solution, comprising the steps of: (a) preparing a polybenzimidazole dope solution comprising: (i) a polybenzimidazole polymer, and (ii) a solvent system for said polybenzimidazole which is water miscible; (b) casting a film of said dope solution onto a support; (c) immersing the film cast on the support into a coagulating medium to form an asymmetric integrally skinned membrane; (d) treating the membrane from step (c) with a cross-linking agent; (e) treating the membrane from step (d) with a cross-link modification agent. Further aspects relate to an asymmetric integrally skinned membrane and uses thereof.

A coated, thin-film composite membrane includes a porous support and a polyamide barrier layer in contact with the porous support. A fouling-resistant and antimicrobial layer of star polymers is in contact with the polyamide barrier layer. The star polymers included hydrophilic arms of about 40 mol % to about 80 mol % of neutral hydrophilic moieties, and about 60 mol % to about 20 mol % of antimicrobial functional groups.

The present invention relates to polymeric membranes. In particular, the present invention relates to the use of membranes comprising polyvinyl alcohol in electrophoresis.

The present invention is related to a method for fabricating multilayer singlebore membranes (10) or multilayer multibore membranes (20) for ultrafiltration applications including the following method steps: (a) feeding at least a material of a substrate (12), at least one material of a functional layer (14, 15) and a bore fluid (36) to a spinneret (30) simultaneously; (b) forming said membranes (10, 20) as a tube-like string (54) in a one-step process in said spinneret (30); (c) thereby assigning a functionality to said functional layer (14, 15) applied on at least one surface (13, 17) of said substrate (12). The invention is also related to a spinneret (30) for fabricating multilayer singlebore membranes (10) or multilayer multibore membranes (20), using the inventive method, and to a system comprising such a spinneret (30).