The present invention relates to an ultrathin-film composite membrane based on a thermally rearranged poly(benzoxazole-imide) copolymer and a production method therefor and to a technique for forming a porous support by means of a thermally rearranged poly(benzoxazole-imide)copolymer and then producing, on the porous support, an ultrathin-film composite membrane comprising a thin-film active layer. The ultrathin-film composite membrane produced according to the present invention has excellent thermal/chemical stability and mechanical physical properties, thus is not only capable of withstanding high operating pressure, but also capable of minimizing internal concentration polarization and thereby obtaining high water permeance and, as a result, high power density, and thus can be applied to a pressure-retarded osmosis or forward osmosis process. Further, said ultrathin-film composite membrane has excellent chemical/thermal stability against organic solvents, has superior organic solvent nano-filtration performance, particularly maintains nano-filtration performance stably even under a high-temperature organic solvent condition, and thus can be applied as an organic solvent nano-filtration membrane.

A membrane for filtering one or more hydrophobic organic contaminants can include a porous nanostructure that includes one or more of a metal, a metal oxide, and a metal alloy nanostructure component functionalized with one or more amphiphilic ligands.

A high-performance thin-film composite polyamide membrane upcycled from a substrate fouled with a biopolymer and a preparation method thereof are provided. The method includes fouling the substrate preferably with the biopolymer to obtain a composite of the substrate and a biopolymer foulant layer; then immersing the composite into a first solution formed by dissolving a polyamine monomer in water, followed by taking the composite out of the first solution and removing excess droplets from a surface of the composite; then immersing the composite treated in the previous step into a second solution formed by dissolving an acyl chloride monomer in n-hexane for interfacial polymerization to form a rejection layer on the surface of the composite; and after completion of the reaction, taking the composite out of the second solution, followed by drying and heat treatment, to obtain the target polyamide membrane.

Separation of linear and branched alkane isomers via selective permeation through a composite membrane is disclosed. The separation layer in the composite membrane is fabricated from a blend of at least two different fluoropolymer compositions, A and B, in which composition A has a normal-alkane isomer permeability that is greater than composition B. Composition B has a normal alkane to branched-alkane isomer selectivity that is equal or greater than composition A. The separation layer in the composite membrane has a normal-alkane permeability that is greater than composition B and a normal-alkane to branched alkane isomer selectivity that is greater than composition A.

Embodiments of the present disclosure describe polymer blend membranes comprising a layer including a polymer blend of regenerated cellulose and polydimethylsiloxane and a support in contact with the layer. Embodiments of the present disclosure describe methods of preparing a polymer blend membrane comprising contacting a cellulose precursor and a PDMS precursor in a solvent to form a polymer blend solution, depositing the polymer blend solution on a surface of a suitable support, curing the PDMS precursor of the polymer blend solution to form PDMS, and converting the cellulose precursor to cellulose to form a polymer blend membrane including cellulose and PDMS. Embodiments of the present disclosure describe methods of separating chemical species by one or more of organic solvent nanofiltration and pervaporation.

A support is a porous ceramic support for supporting a zeolite membrane. The hydraulic conductivity of the support is less than or equal to 1.110.sup.3 m/s. In the support, the total content of alkali metal and alkaline earth metal in a surface part within 30 m from a surface in a depth direction perpendicular to the surface is less than or equal to 1% by weight.

Provided are an inexpensive, high-quality, permeation-side flow path material that is suitable for use in spiral membrane elements and enables the improvement of productivity, a method for producing such a permeation-side flow path material, and a membrane element having such a permeation-side flow path material. Provided are (a) a permeation-side flow path material for use in a spiral membrane element, the permeation-side flow path material comprising a resin sheet comprising a plurality of ridge portions 31 formed parallel to one another; and a plurality of openings 32 formed between each pair of the ridge portions 31, (b) a method for producing such a permeation-side flow path material, and (c) a membrane element having such a permeation-side flow path material.

A porous ultra-thin polymer film has a film thickness of 10 nm-1000 nm. A method of producing the porous ultra-thin polymer film includes dissolving two types of mutually-immiscible polymers in a first solvent in an arbitrary proportion to obtain a solution; applying the solution onto a substrate and then removing the first solvent from the solution applied onto the substrate to obtain a phase-separated ultra-thin polymer film that has been phase-separated into a sea-island structure; and immersing the ultra-thin polymer film in a second solvent which is a good solvent for the polymer of the island parts but a poor solvent for a polymer other than the island parts to remove the island parts, thereby obtaining a porous ultra-thin polymer film.

A semipermeable ultrathin polymer membrane comprises a substantially optically transparent polymer film having a surface area to thickness ratio of at least 1,000,000:1, and an array of precisely spatially ordered pores of a user-selected diameter defined therethrough. Such membranes can be fabricated by providing a mold having a patterned array of nanoholes femtosecond laser ablated in a surface thereof; applying a first polymer solution onto the mold surface so that the first polymer solution infiltrates the nanoholes; allowing the first polymer solution to dry and form a replica of the mold having a plurality of freestanding nanoneedles extending from a surface of the replica; removing the replica from the mold; coating the replica surface with a second polymer solution; drying the second polymer solution to form a porous polymer film; and dissolving the replica in a solvent to release the film from the replica as a semipermeable ultrathin polymer membrane.

Disclosed are a method of manufacturing a polyethylene membrane comprising: stretching a polyethylene film in a first direction during a first stretching; attaching a plurality of rods on side edges of the polyethylene film; attaching a tape on the polyethylene film; stretching the polyethylene film having the rods attached thereto in a second direction during a second stretching; and annealing the polyethylene film after the second stretching. The second direction can be a transverse direction of the first direction, and the first stretching and the second stretching can be performed at the same (or higher) temperature and the same stretching speed as each other.