A membrane contains a polymer composition is described. The polymer composition contains a) at least one polymer of PA, PVA, Cellulose CA, CTA, CA-triacetate blend, cellulose ester, cellulose nitrate, regenerated cellulose, aromatic, aromatic/aliphatic or aliphatic polyamide, aromatic, aromatic/aliphatic or aliphatic polyimide, PBI, PBIL, PAN, PAN-PVC copolymer, PAN-methallyl sulfonate copolymer, PEI, PEEK, sulfonated SPEEK, PPO, poly-carbonate, polyester, PTFE, PVDF, PP, a polyelectrolyte complex, PMMA, PDMS, aromatic, aromatic/aliphatic or aliphatic polyimide urethane, aromatic, aromatic/aliphatic or aliphatic polyamidimide, crosslinked polyimide or poly-arylene ether, PSU, PPSU and PESU, and b) at least one dope polymer DP1, which is a polyalkylene oxide with a molecular mass Mw of more than 100,000 g/mol and/or a K-value of 60 or 20 more.

Described in the present application are methods of producing silane-crosslinked polymer membranes at moderate temperatures using acid catalysts that, in certain embodiments, result in membranes with unexpectedly high permeabilities and selectivities. In certain embodiments, grafting and crosslinking of the silanes occur by immersing a preformed membrane in a solution comprising a silane and an acid catalyst. Alternatively, in certain embodiments, grafting of silanes to a polymer occurs in the presence of acid catalyst in solution and subsequent casting and drying produces crosslinked membranes. In certain embodiments, an acid catalyst is a weak acid catalyst. Also described in the present application are asymmetric crosslinked polymer membranes with porous layers. In certain embodiments, crosslinked cellulose acetate membranes have permeability up to an order of magnitude greater than the permeability of unmodified cellulose acetate membranes. The membranes have porous layers with a high porosity due to their processing in moderate conditions.

The embodiments described herein relate to agarose ultrafiltration membrane composites and methods for making and using the same.

Asymmetric membranes in hollow fiber and flat sheet forms are disclosed herewith. The process of preparation of the membranes is further disclosed. The membranes are characterized and find application in the separation of gases and solutes.

A gas separation membrane, methods of forming the membrane, and methods of using the membrane for gas separation are provided. An exemplary gas separation membrane includes a cellulosic matrix and a polymer of intrinsic microporosity (PIM). The PIM includes chains coupled by a heat-treating under vacuum.

A method of manufacturing a composite film, the method including: preparing a coating liquid including a resin and a filler and having a viscosity of from 0.1 Pa.Math.s to 5.0 Pa.Math.s: removing aggregates contained in the coating liquid by making the coating liquid pass through a filter having a minimum pore diameter that is larger than a maximum particle diameter of the aggregates; applying the coating liquid that has been subjected to the aggregate removal on one surface or both surfaces of a porous substrate, to form a coating layer; and solidifying the resin contained in the coating layer, 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 contains the resin and the filler.

A hollow fiber membrane and a method of preparing the same. The hollow fiber membrane has an inner surface and an outer surface, wherein the inner surface has a zebra-stripe pattern in which a dense portion and a porous portion are alternately formed in a longitudinal direction of the hollow fiber membrane.

An object of the present invention is to provide a porous hollow-fiber membrane having high strength while maintaining high pure-water permeation performance. A porous hollow-fiber membrane of the present invention is a porous hollow-fiber membrane including a fluororesin-based polymer, in which the porous hollow-fiber membrane has a columnar texture oriented in a longitudinal direction of the porous hollow-fiber membrane, and a molecular chain of the fluororesin-based polymer is oriented in the longitudinal direction of the porous hollow-fiber membrane.

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.