The use of polymer separation membranes to selectively separate CO.sub.2 and H.sub.2 from CH.sub.4 in a membrane separation step for purifying methane contained in an optionally pre-dried product gas mixture of a methanation method which contains CH.sub.4, H.sub.2 and CO.sub.2 is described. a) The separation is carried out at an operation temperature T.sub.B between 20 C. and 100 C.; and b) the polymer membranes b1) are able to simultaneously separate CO.sub.2 and H.sub.2 from CH.sub.4, b2) have a higher selectivity for the separation of CO.sub.2 than of H.sub.2 from CH.sub.4, i.e., a ratio 1/2<1, and b3) have a glass transition temperature T.sub.g that is lower than the operation temperature T.sub.B.

A process for producing nitrogen-rich air by feeding high temperature air at 150 C. or more to an air separation membrane module is described. After being placed at 175 C. for two hours, the air separation module exhibits a shape-retention ratio of 95% or more in one embodiment. The nitrogen-rich air can be fed to a fuel tank for an aircraft, for example.

A method of separating gas and a method of making a gas separation membrane. The method of separating gas includes flowing a gas stream through a membrane, in which the membrane comprises a crosslinked mixture of a poly(ether-b-amide) copolymer and an acrylate-terminated poly(ethylene glycol) according to formula (I) or formula (II); and separating the gas stream via the membrane.

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In formulas (I) and (II), each n is of from 2 to 30; and each R is independently H or CH.sub.3.

Provided are UHMW polymers having a molecular weight of 500 kg/mol or greater. The UHMW polymers can be block copolymers, homopolymers, and random/statistical copolymers. The UHMW polymers can be used to form porous layers, which may be used in filtration membranes, such as, for example, ultrafiltration membranes. The filtration membranes can be used in various separation methods.

A method of separating gas and a method of making a gas separation membrane. The method of separating gas includes flowing a gas stream through a membrane, in which the membrane comprises a crosslinked mixture of a poly(ether-b-amide) copolymer and an acrylate-terminated poly(ethylene glycol) according to formula (I) or formula (II); and separating the gas stream via the membrane. ##STR00001##
In formulas (I) and (II), each n is of from 2 to 30; and each R is independently H or CH.sub.3.

A fluid control device includes a support structure configured to be deployed to a selected location in a borehole, and a filtration medium disposed at the support structure and configured to filter a fluid, the filtration medium configured to be compacted from an initial shape to a compacted shape prior to deployment in the borehole. The filtration medium includes a first polymeric material configured to withstand a temperature at the selected location, the first polymeric material forming a porous structure including a plurality of fluid passages, and a second polymeric material including a shape memory polymer disposed within the fluid passages, the shape memory polymer configured to expand in the plurality of fluid passages and cause the filtration medium to expand in the borehole.

Disclosed herein are asymmetric multilayer carbon molecular sieve (CMS) hollow fiber membranes and processes for preparing the membranes. The processes include simultaneously extruding a core dope containing a polymer and suitable nanoparticles, a sheath dope, and a bore fluid, followed by pyrolysis of the extruded fiber.

Membrane materials and methods are disclosed for selectively separating or transporting ions in liquid media. In embodiments, the membranes comprise cellulose acetate polymer films having high cation, monovalent/divalent, and/or Li.sup.+/Mg.sup.2+ selectivity. Systems and methods for use of such membranes, including the direct extraction of lithium (DLE) from natural brines and other resources, also are disclosed.

A polymer composite membrane, a method for fabricating same, and a lithium-ion battery including same are provided. The polymer composite membrane includes a porous base membrane and a heat-resistant layer covering at least one side surface of the porous base membrane, the heat-resistant layer includes a plurality of heat-resistant sub-layers sequentially stacked, and pore-blocking temperatures of the heat-resistant sub-layers are sequentially increased from inside to outside; each of the heat-resistant sub-layers includes at least one of a first heat-resistant polymer material and a second heat-resistant polymer material, and each of the heat-resistant sub-layers is separately configured as a fiber network structure; the melting point of the first heat-resistant polymer material is not less than 200 C.; and the melting point of the second heat-resistant polymer material is not less than 100 C.

The present invention relates to polymer compositions (C) for the preparation of porous article, notably microporous membranes or hollow fibers. More particularly, the present invention relates to a process of preparing a porous article from a blend of at least one semi-crystalline or amorphous polymer (P) with an additive followed by a step of shaping the article and contacting the article with water to dissolve the additive and create an interconnected pore network within the shaped article.