Provided is a nanofiltration (NF) or reverse osmosis (RO) membrane made of a hard carbon film that has oil resistance and can efficiently separate not only ions in water but also dye molecules present in an organic solvent, a filtering filter, a two-layer-bonded-type filtering filter, and methods for manufacturing the same, using a nanofiltration (NF) or reverse osmosis (RO) membrane (10) made of a hard carbon film characterized by being made of a hard carbon film, having a thickness (t.sub.10) of from 5 nm to 300 nm, and having a maximum pore diameter of less than 0.86 nm.

The present invention relates to a method of preparing a perm-selective porous membrane and a method of separating gases using the prepared porous membrane. According to the present invention, a membrane is synthesized using a hierarchically structured alumina porous support by a counter diffusion method. During this synthesis, the diffusion rate of metal ions loaded on the porous support is controlled by controlling the pore size of the porous support, and the position at which the membrane is synthesized is controlled by synthesizing the membrane inside the support. This can increase the physical stability of the membrane and make the membrane thicker so as to ensure higher H.sub.2/CO.sub.2 separation factors.

The present disclosure provides a fluorine-based resin porous membrane exhibiting high mechanical strength and low heat shrinkage rate while having a fine pore size, and a method for preparing the same.

Porous air permeable expanded PTFE composite with enhanced mechanical and thermal properties are described. The node and fibril microstructure of expanded PTFE is coated on and within the node and fibril microstructure with a suitably chosen polymer to impart property enhancement while maintaining porosity. The coating polymer content of the composite is maintained between 3 and 25 weight percent of the composite and the areal mass of the composite is less than 75 gm/m.sup.2. Exemplary enhancement to properties may include, among others, Average Tensile Strength (ATS) (in MPa)Z strength (in MPa) of 50 MPa.sup.2 or greater, preferably 100 MPa.sup.2 or greater, with air flow less than 500 Gurley seconds. Coating polymers with appropriate temperature resistance provides composites which further exhibit shrinkage of less than 10% at temperatures up to 300 C. with air flow of less than 500 Gurley seconds.

The present application discloses a composite reverse osmosis membrane and a preparation method thereof. The method includes: uniformly mixing fluorine-containing polyaryletherketone of a certain concentration and silane-modified polyaryletherketone as a casting solution; coating a non-woven fabric, i.e., a substrate, with the casting solution to form a support layer; then coating the surface of the support layer with a solution A and a solution B sequentially for reaction to form a polyamide desalination layer; and coating the polyamide desalination layer with a modified polyvinyl alcohol anti-pollution layer. By means of the method, the composite reverse osmosis membrane is prepared. Compared with the prior art, the present application can prepare a composite reverse osmosis membrane with high temperature resistance and high strength by using the composite modified polyaryletherketone as the support layer, and moreover, uses polyvinyl alcohol as a component of the anti-pollution layer, and has good anti-pollution properties.

Provided is a method for separating ammonia gas using zeolite membrane having excellent separation stability at a high temperature capable of separating ammonia gas from a mixed gas composed of multiple components including ammonia gas, hydrogen gas, and nitrogen gas to the permeation side with high selectivity and high permeability. Also provided is a method for separating ammonia by selectively permeating ammonia gas from a mixed gas containing at least ammonia gas, hydrogen gas, and nitrogen gas using a zeolite membrane, wherein the ammonia gas concentration in the mixed gas is 1.0% by volume or more.

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.

Polymer membranes include a polymer material that is selectively permeable to acidic gases over methane in a gas stream, such as natural gas. The polymer material may be a polymer membrane comprising a fluorinated polytriazole polymer. The fluorinated polytriazole polymer may further comprise a substituted phenyl or a substituted benzenaminyl. The substituted phenyl or substituted benzenaminyl may be substituted with hydrogen, bromo, fluoro, chloro, iodo, hydroxy, methyl, trifluoromethyl, dimethylamino, tert-butyl, or difluoromethoxy groups. The polymer material may have a degree of polymerization of from 100 to 175. The polymer membranes may be incorporated into systems or methods for removing separable gases, such as acidic gases, from gas streams, such as natural gas.

A method of concentrating a lithium-containing aqueous solution, the method comprising: (i) providing a water-permeable structure having an inner surface and outer surface, wherein at least said outer surface is coated with a water-permeable hydrophilic polymer having a thermal stability of at least 100 C.; and (ii) flowing a lithium-containing aqueous feed solution having an initial concentration of lithium over said inner surface while said outer surface is in contact with an aqueous draw solution containing a higher overall ion concentration than said lithium-containing aqueous feed solution, to result in forward osmosis of water from said lithium-containing aqueous feed solution to said aqueous draw solution, and wherein said forward osmosis results in a lithium-containing aqueous product solution having an increased concentration of lithium relative to the initial concentration of lithium in the lithium-containing aqueous feed solution.

The invention provides a hollow fiber membrane exhibiting a favorable gas permeation performance and an excellent heat resistance in which the generation of pinholes are suppressed, and a hollow fiber membrane module using the same. The hollow fiber membrane comprising a gas permeable nonporous layer; and a porous supporting layer to support the nonporous layer formed of a thermoplastic elastomer having a DSC melting peak temperature of 130 C. or higher and a rupture elongation prescribed in ISO 37 (2010) of 300% or more.