A co-cast thin film composite flat sheet membrane is provided that comprises an asymmetric porous non-selective support layer with a thickness of 10-50 micrometers and an asymmetric integrally skinned polyimide-containing selective layer with a thickness of 5-40 micrometers on top of said support layer, wherein said asymmetric integrally skinned polyimide-containing selective layer comprises a porous non-selective polyimide-containing support layer with a thickness of 5-40 micrometers and a relatively porous, thin, dense, polyimide-containing top skin layer with a thickness of 0.02-0.2 micrometers.

An environmentally friendly closed loop manufacturing process (10.sub.1, 10.sub.2) produces microporous membranes (32) by cast or extrusion of polymer-plasticizer mixtures followed by non-porous film formation (20), extraction (22) of the plasticizer using an azeotrope solvent and thereby forming a solvent-laden sheet and a mixture of plasticizer and azeotrope solvent, distillation (28) of the mixture to separate the plasticizer and azeotrope solvent for reuse, evaporation (30) of the azeotrope solvent from the solvent-laden sheet to form the micropores, and capture of the resultant solvent vapor for subsequent adsorption-desorption of the azeotrope solvent from activated carbon (34) or by vapor condensation (36) for reuse in the manufacturing process. The azeotrope solvent is at least a two-component mixture of solvents, one of which is designed for efficient removal of the plasticizer, while the other component(s) render(s) the azeotrope solvent non-flammable.

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).

The invention provides polymeric membranes with a mixed matrix and hollow fibers, with high mechanical resistance, useful in high pressure gas permeation processes such as, in particular, the removal of CO.sub.2 from raw streams resulting from oil exploration. The membranes are formed by at least one polymeric layer consisting of at least one polymer and an inorganic filler of clay mineral nanoparticles. The respective co-extrusion processes applicable to the production of said membranes are also provided herein.

In embodiments of the present disclosure, a CMS hollow fiber membranes may be prepared to have an ultrathin (e.g. 2 microns or less) separation layer. A precursor hollow fiber may be prepared as dual layer fibers having a thin sheath layer and a core layer. During pyrolysis, the sheath layer is transformed into an ultrathin separation layer. Porosity of the core layer substrate is well-maintained during pyrolysis, thereby enabling high permeance of the CMS hollow fiber membrane. Additionally, in some embodiments, the sheath layer of the precursor hollow fibers may be hybridized prior to pyrolysis. By hybridizing the sheath layer prior to pyrolysis, a CMS hollow fiber may having an improved separation factor, including for example increased carbon dioxide/methane selectivity, may be provided.

A co-cast thin film composite flat sheet membrane is provided that comprises an asymmetric porous non-selective support layer with a thickness of 10-50 micrometers and an asymmetric integrally skinned polyimide-containing selective layer with a thickness of 5-40 micrometers on top of said support layer, wherein said asymmetric integrally skinned polyimide-containing selective layer comprises a porous non-selective polyimide-containing support layer with a thickness of ?5-40 micrometers and a relatively porous, thin, dense, polyimide-containing top skin layer with a thickness of 0.02-0.2 micrometers.

A method of manufacturing a green body, the method comprising: providing: a third composition comprising a second substrate material, a third polymer, a fusing agent, and a third solvent; forming the third composition into a structure wherein the third composition forms a third layer; and contacting the third layer with a fourth solvent in which the third polymer is insoluble to precipitate said polymer, thereby forming a green body.

A substrate is further manufactured by: arranging a plurality of green bodies to form an assembly of green bodies;
fusing the green bodies in the assembly together, thereby forming a precursor substrate; and sintering the precursor substrate, thereby forming a substrate.

Methods of preparing reinforced anion exchange membranes are provided, as well as produced membranes and corresponding devices utilizing the membranes. Methods comprise compounding a halide-functionalized polymer (selected to react with amines to yield anion-conducting quaternary amine groups) with thermoplastic polymer(s) (selected to support and/or reinforce the membrane), and with copolymer(s) (selected to enhance the compounding of the polymers)by heating, mixing and coolingto form blend pellets, extruding the blend pellets to form a blend film, cross-linking polymer(s), and functionalizing the blend film to prepare the anion exchange membrane. Functionalization comprises a quaternization step comprising reacting halogen groups of the first polymer with tertiary amines to produce the quaternary amine groups with ion-exchange functionality. Reinforced anion exchange membranes are provided, which are produced by the disclosed methods, functionalized to yield a membrane for fuel cell(s), electrolyzer(s), reversible electrochemical device(s), desalination unit(s), etc.

A method (500) for conditioning or hydrolysis of an extruded membrane is disclosed. The method (500) comprising ion exchange processes in divided electrochemical cells using a cation exchanger membrane. The method (500) includes extruding the perfluorosulfonyl fluoride membranes from perfluorosulfonyl fluoride granulate. The method (500) also includes using a pretreatment technique to increase the ionic conductivity of the extruded perfluorosulfonyl fluoride membranes before using the perfluorosulfonic acid membranes in electrolysis cells. The method (500) also includes applying a milder pretreatment technique by activating SF bonds to execute nucleophilic exchange of the fluoride group in a reaction. The method (500) also includes hydrolyzing sulfonyl fluoride groups to sulfonic acid using triethylsilanol.

A method of manufacturing a hollow fiber carbon membrane, the method includes heating a polymeric precursor to a pyrolysis temperature that is greater than or equal to 900? C. and less than or equal to 1200? C., and pyrolyzing the polymeric precursor at the pyrolysis temperature in a pyrolysis atmosphere that comprises oxygen in an amount that is greater than 0 ppm and less than 200 ppm.