Provided is a method for separating a specific gas from a raw gas using a gas separation membrane module that includes a gas separation membrane element enclosed in a housing. The element includes a gas separation membrane including a hydrophilic resin composition layer. The method includes: preparing the module; increasing pressure in an interior of the module; increasing a temperature in the interior; and feeding a raw gas to the interior. The layer of the module prepared is adjusted to contain moisture, and a moisture content thereof is an amount that allows an equilibrium relative humidity at a temperature of 23? C. of a gas phase portion in the housing to be 10% RH or more. The raw gas feeding step is performed after the preparation step. The pressure increase step and the temperature increase step are performed after the preparation step and before the raw gas feeding step.

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.

Metallopolyimide precursor fibers for aging-resistant carbon molecular sieve hollow fiber membranes having enhanced selectivity include transition metal cations complexed with electronegative regions of a polyimide. CMS membranes are made by pyrolyzing the metallopolyimide precursor fibers. The cations are introduced by including, in the bore fluid used to extrude the fibers, either a salt of the transition metal and an inorganic anion or a transition metal/organic ligand complex.

Metallopolyimide precursor fibers for aging-resistant carbon molecular sieve hollow fiber membranes having enhanced selectivity include transition metal cations complexed with electronegative regions of a polyimide. CMS membranes are made by pyrolyzing the metallopolyimide precursor fibers. The cations are introduced by including, in the spin dope composition used to extrude the fibers, either a salt of the transition metal and an inorganic anion or a transition metal/organic ligand complex.

Described are membranes for separating olefins from a mixture that includes olefins and non-olefins. The membrane includes polymers and metal ions associated with the polymers. The metal ions mediate the transport of the olefins through the membrane by selectively and reversibly coupling with the olefins. The olefin/non-olefin selectivity of the membrane remains within at least 80% of its original selectivity after 200 hours of exposure of the membrane to a stream of hydrogen gas, 100 hours of exposure to a stream of acetylene gas, and 100 hours of exposure to a stream of hydrogen sulfide gas. Additional embodiments of the present disclosure pertain to methods of utilizing the membranes of the present disclosure to separate olefins from a mixture that includes olefins and non-olefins.

The present invention includes membranes comprising one or more cellulosic materials and wetting agent(s), and methods of making such membranes.

A polymer fiber formed of statistical copolymers, each of which contains zwitterionic repeat units and hydrophobic repeat units, the zwitterionic repeat units constituting 20-75 wt % of the statistical copolymer and the hydrophobic repeat units being characterized in that a homopolymer formed thereof has a glass transition temperature above room temperature. Also disclosed is a fibrous membrane containing such polymer fibers in which greater than 90% of the polymer fibers are each independently rib bon-shaped fibers or wrinkly fibers. A method of preparing such a fibrous membrane is disclosed as well.

A method of manufacturing a composite film, the method including: a coating step including coating a coating liquid containing a resin on one surface or both surfaces of a porous substrate to form a coating layer; a solidification step including solidifying the resin by bringing the coating layer into contact with a solidifying liquid to obtain a composite film including the porous substrate and a porous layer that is formed on one surface or both surfaces of the porous substrate and that includes the resin; a water washing step including washing the composite film with water; and a drying step including drying by removing water from the composite film while transporting the composite film at a transport speed of 30 m/min or more using a drying apparatus including a drying device including a contact type heating device and a hot air blowing device, wherein the composite film is brought into contact with a contact type heating device as well as exposed to hot air blown from a hot air blowing device, to remove water from the composite film being performed by bringing.

An ion exchange membrane is provided which includes an ion exchange polymer that is partially cross-linked. The partially cross-linked ion exchange polymer will be more stable and will not be washed out over time. The ion exchange polymer may be UV or chemically cross-linked, wherein a cross-linking compound is added to the ion exchange polymer either before or after coupling to a support material. A support material may be made of, or be coated with, a cross-linking compound and the support material may initiate cross-linking proximal to the support material. The support material may be made of a material that chemically bonds with the ionomer.

Provided is an interfacial polymerization process for preparation of a thin film composite membrane, which can be used for nanofiltration, forward osmosis, or reverse osmosis, particularly for use with brackish water or seawater. The process includes contacting a porous support membrane with an aqueous phase containing a polyamine to form a coated support membrane, and applying an organic phase containing a polyfunctional acyl halide to the coated support membrane to interfacially polymerize the polyamine and the polyfunctional acyl halide to form a discrimination layer of a thin film composite membrane, where during formation of the membrane, the polyfunctional acyl halide is purified in situ by removal of hydrolyzed acyl halide through addition of a salt rejection-enhancing additive that includes a biguanide compound, dicarbonate compound, pentathiodicarbonate compound, or salt thereof. Also provided are the membranes prepared by the methods and reverse osmosis modules containing the membranes.