The present invention provides an intrinsically anti-microbial hollow fiber membrane for filtration of liquids. The membrane comprises a plurality of porous hollow bilayer membrane fibers wherein the liquid enters from outside of the fiber, passing through the porous membrane into the lumen of the fiber and coming out from the hollow ending of the fiber, wherein this configuration provides a liquid outside-in arrangement and retains the filtrate outside. It means that membrane of the invention has built in characteristics to act against microbes in order to provide the use with a safe liquid free from microbes. The outer side or outer wall of the hollow fibers may be configured to become hydrophobic whereas inner side or inner wall of the hollow fiber membrane may be configured to become hydrophilic to enhance the water permeability to a great extent. The hollow fiber membrane may be configured to give it an intrinsic anti-microbial capability. A device containing above said membrane has also been disclosed.

The present invention deals with a method for obtaining membranes in the form of hollow fibers with application in the field of carbon dioxide removal from natural gas. The aforementioned membranes are obtained by means of heat treatment of polymeric membranes. In this method, polymeric membranes are obtained by a phase-inversion technique by immersion-precipitation and are subsequently subjected to a heat treatment, that is, that the membranes effectively become precursor membranes of the heat treatment. The heat treatment process involves the optimization of the heating rate, temperature, and stabilization time variables, aiming at the improvement of the transport properties of the polymeric membranes. After the heat treatment, it becomes possible to use the membranes in separation processes of gases which operate at pressures greater than 30 bar, with selectivity for carbon dioxide (CO.sub.2).

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 polyvinylidene fluoride (PVDF) casting membrane solution is shaped as a flat sheet membrane by thermally induced phase separation (TIPS), the PVDF membrane is defluorinated with an alkaline potassium permanganate solution, and then the carbon chain is extended with glycidyl methacrylate (GMA) as the graft monomer, and finally the nucleophilic substitution is carried out between melamine and GMA to produce a chelating microfiltration membrane for capturing and enriching heavy metals with high flux and high capacity.

The problem addressed by the present invention is to provide a separation membrane with superior permeation performance and separation performance and having few occurrences of defects. The present invention relates to a separation membrane wherein: the separation membrane has a layer (I) with a thickness of 0.5-100 m; letting, in a cross-section in the direction of thickness of the layer (I), region a be a region with a depth of 50-150 nm from a surface (surface A), region b a region with a depth of 50-150 nm from the other surface (surface B), and region c a region with a thickness of 100 nm where the depth from both surfaces is the same, the average pore diameter Pa for region a and the average pore diameter Pb for region b are both 0.3-3.0 nm and the average pore diameter Pc for region c is 3.0 nm or less; and the percentage of open area Ha for region a, the percentage of open area Hb for region b, and the percentage of open area Hc for region c satisfy the following equations. 2Hc<Ha 2Hc<Hb

The present invention provides an intrinsically anti-microbial hollow fiber membrane for filtration of liquids. The membrane comprises a plurality of porous hollow bilayer membrane fibers wherein the liquid enters from outside of the fiber, passing through the porous membrane into the lumen of the fiber and coming out from the hollow ending of the fiber, wherein this configuration provides a liquid outside-in arrangement and retains the filtrate outside. It means that membrane of the invention has built in characteristics to act against microbes in order to provide the use with a safe liquid free from microbes. The outer side or outer wall of the hollow fibers may be configured to become hydrophobic whereas inner side or inner wall of the hollow fiber membrane may be configured to become hydrophilic to enhance the water permeability to a great extent. The hollow fiber membrane may be configured to give it an intrinsic anti-microbial capability. A device containing above said membrane has also been disclosed.

The invention relates generally to forward osmosis membranes and methods of making forward osmosis membranes, in particular improved thin support layer upon which an active layer is cast.

The present invention provides an intrinsically anti-microbial hollow fiber membrane for filtration of liquids. The membrane comprises a plurality of porous hollow bilayer membrane fibers wherein the liquid enters from outside of the fiber, passing through the porous membrane into the lumen of the fiber and coming out from the hollow ending of the fiber, wherein this configuration provides a liquid outside-in arrangement and retains the filtrate outside. It means that membrane of the invention has built in characteristics to act against microbes in order to provide the use with a safe liquid free from microbes. The outer side or outer wall of the hollow fibers may be configured to become hydrophobic whereas inner side or inner wall of the hollow fiber membrane may be configured to become hydrophilic to enhance the water permeability to a great extent. The hollow fiber membrane may be configured to give it an intrinsic anti-microbial capability. A device containing above said membrane has also been disclosed.

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.

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.