A hollow fiber filtration membrane in which even when a relatively small contaminant having a size close to that of a permeation effective component is present in a filtration solution, Flux decrease over time during filtration is suppressed, and a useful component can be efficiently recovered, the hollow fiber filtration membrane including a polysulfone-based polymer and a hydrophilic polymer and having a large number of pores, the hollow fiber filtration membrane having a gradient asymmetric porous structure in which an average pore diameter of the pores increases from an outer surface portion toward an inner surface portion of the membrane, a content of the hydrophilic polymer of the membrane being from 6.0 to 10.0% by mass, a ratio between a content of the hydrophilic polymer at the inner surface portion and the content of the hydrophilic polymer of the membrane being in the range of from 0.50 to 0.80.

A carbon molecular sieve (CMS) membrane is made by pyrolyzing a polymeric precursor membrane in a pyrolysis atmosphere containing a sulfur-containing compound.

Disclosed are a CMS membrane, characterized in that it is obtainable by pyrolysis of a polyimide composed of the monomers 1-(4-aminophenyl)-1,3,3-trimethyl-2H-inden-5-amine and 5-(1,3-dioxo-2-benzofuran-5-carbonyl-2-benzofuran-1,3-dione of the following formulae:

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preferably by pyrolysis of the polyimide having the CAS number 62929-02-6, and a supported CMS membrane comprising a CMS membrane obtainable from a polyimide by pyrolysis and a porous support, characterized in that a mesoporous intermediate layer is provided between the CMS membrane and the porous support.

Further disclosed are a process for preparing the supported membrane, the use of the membranes for separating gas mixtures or liquid mixtures, an apparatus for gas separation or for liquid separation, and the use of the polyimide for preparing a CMS membrane by pyrolysis.

A reverse osmosis membrane of the present invention includes a porous support substrate (2) and a separation active layer (3) formed on a surface of the porous support substrate (2) and formed of a carbon film containing organized carbon.

The present invention offers a forward osmosis composite hollow fiber membrane module having hollow fiber bundles comprising a plurality of hollow fibers, the hollow fibers having a separation layer composed of a macromolecular polymer thin film provided on the inner surface of a microporous hollow fiber supporting membrane, wherein the membrane area of the hollow fiber bundle is at least 1 m.sup.2, and a variation coefficient for the average thickness of the separation layer in the radial direction and the lengthwise direction of the hollow fiber bundles, as calculated by a method of measuring the mass of the separation layer portion in a scanning electron microscope image of a cross section of the separation layer in the thickness direction, is 0% to 60%.

A substrate surface may be modified with a polymer coating to render the surface suitable for plasma functionalization. The polymer coating is deposited onto the surface at ambient temperature to a thickness of less than 0.1 μm. The polymer coating includes poly(p-xylylene) or a derivative thereof, and is capable of penetrating into pores of a porous substrate while no substantially altering the porosity of the substrate. The coated substrate is selected from a material lacking a primary or secondary aliphatic hydrogen atom.

The present disclosure discloses a method for preparing a metal-organic framework filter comprising the steps of bringing metal sources into contact with organic ligands and forming a metal-organic framework filter on substrates by a hot-pressing method. By the method of the present disclosure, a large amount of metal-organic framework filters with high purity can be obtained quickly and easily, thereby realizing industrialized production and application and the method has such advantages as low cost, simple operation, rapid production, batch product and high purity.

A supported carbon molecular sieve (CMS) membrane is made by contacting a film of a carbon forming polymer on a polymer textile to form a laminate. The laminate is then heated to a temperature for a time under an atmosphere sufficient to carbonize the film and polymer textile to form the supported CMS membrane. The supported CMS membrane formed is a laminate having a carbon separating layer graphitically bonded to a carbon textile, wherein the carbon separating layer is a continuous film. The supported CMS membranes are particularly useful for separating gases such as olefins from their corresponding paraffins.

Disclosed are methods of manufacturing a zeolite membrane, comprising: providing at least one porous substrate; and coating the at least one porous substrate with a membrane. In some embodiments, the method further comprises hydrothermally treating the membrane with a first hydrothermal treatment step with tetrapropylammonium fluoride (TPAF) and a second hydrothermal treatment step with tetraethammonium hydroxide (TEAOH). In some embodiments, coating the substrate with a membrane comprises surrounding at least a portion of the at least one porous substrate with a precursor gel, the gel comprising a gel phase and a plurality of CHA or MFI crystals; heating the at least one porous substrate and the precursor gel; washing the at least one porous substrate; drying the at least one porous substrate; and calcining the at least one porous substrate.

Disclosed is a nano membrane which has improved dustproofness and thus effectively prevents matter, contaminants/dust, and the like from getting into an electronic device such as a PCB or a MEMS microphone, and has no air and sound permeability degradation. The nano membrane of the present disclosure contains a plurality of pores having an average diameter of 0.5-20 μm, wherein the maximum diameter of each of the pores is 30 μm, the minimum diameter of each of the pores is 0.1 μm, and the porosity of the nano membrane is 50-90%.