The present invention relates to a composite semipermeable membrane including: a support membrane; and a separation functional layer provided on the support membrane, in which the separation functional layer comprises a plurality of protrusions formed of a thin membrane, and at least a part of the plurality of protrusions has a ratio (Wa/Wb) of larger than 1.3 in cross sections at arbitrary ten positions each having a length of 2.0 m in a membrane surface direction of the support membrane, provided that Wa is a maximum width of the protrusion and Wb is a root width of the protrusion.

A low cost, high selectivity asymmetric polyimide/polyethersulfone (PES) blend hollow fiber membrane, a method of making the membrane and its use for a variety of liquid, gas, and vapor separations such as deep desulfurization of gasoline and diesel fuels, ethanol/water separations, pervaporation dehydration of aqueous/organic mixtures, CO.sub.2/CH.sub.4, CO.sub.2/N.sub.2, H.sub.2/CH.sub.4, He/CH.sub.4, O.sub.2/N.sub.2, H.sub.2S/CH.sub.4, olefin/paraffin, iso/normal paraffins separations, and other light gas mixture separations. The polyimide/PES blend hollow fiber membrane is fabricated from a blend of a polyimide polymer and PES and showed surprisingly unique gas separation property with higher selectivities than either the polyimide hollow fiber membrane without PES polymer or the PES hollow fiber membrane without PES polymer for gas separations such as for H.sub.2/CH.sub.4, He/CH.sub.4, H.sub.2S/CH.sub.4, CO.sub.2/CH.sub.4 separations.

A method for preparing a nanofiltration membrane and a nanofiltration membrane prepared therefrom, the method comprising the following steps: dissolving a polymer in a solvent to prepare a polymer solution, and curing the polymer solution on a support material to form a base membrane; sequentially applying a first liquid-phase solution and a second liquid-phase solution on the base membrane to form a nascent membrane; densifying the nascent membrane by using a solution that contains an alkaline substance; processing the densified nascent membrane by using a solution that contains an acidic substance; and obtaining the nanofiltration membrane after post-processing and drying.

Nanoporous selective sol-gel ceramic membranes, selective-membrane structures, and related methods are described. Representative ceramic selective membranes include ion-conductive membranes (e.g., proton-conducting membranes) and gas selective membranes. Representative uses for the membranes include incorporation into fuel cells and redox flow batteries (RFB) as ion-conducting membranes.

The present invention relates to a porous ABPBI (phosphoric acid doped poly (2, 5-benzimidazole)) membrane and process of preparing the same. A stable porous ABPBI (Phosphoric Acid Doped Poly (2, 5-benzimidazole)) membrane stable to acids, bases, solvents and autoclaving is disclosed. The membrane finds use for separation of solutes in solution in acids, bases and solvents.

The present invention relates to a porous ABPBI (phosphoric acid doped poly (2, 5-benzimidazole)) membrane and process of preparing the same. A stable porous ABPBI (Phosphoric Acid Doped Poly (2, 5-benzimidazole)) membrane stable to acids, bases, solvents and autoclaving is disclosed. The membrane finds use for separation of solutes in solution in acids, bases and solvents.

The present invention relates to a process for the preparation of a supported Carbon Membranes (CMS). The present invention also relates to a process for the separation of a gas from a gas mixture and to the use of use of a supported CMs as a membrane reactor or in a membrane reactor.

A porous asymmetric membrane comprises a hydrophobic polymer comprising a poly(phenylene ether) or poly(phenylene ether) copolymer; and a polymer additive. A separation module can be fabricated from the porous asymmetric membrane. A method of forming the porous asymmetric membrane comprises: dissolving a hydrophobic polymer comprising a poly(phenylene ether) or poly(phenylene ether) copolymer and, a polymer additive in a water-miscible polar aprotic solvent to form a porous asymmetric membrane-forming composition; and phase-inverting the porous asymmetric membrane forming-composition in a first non-solvent composition to form the porous asymmetric membrane. The polymer additive comprises hydrophilic functional groups, copolymerized hydrophilic monomers, or blocks of hydrophilic monomer repeat units. For example, the polymer additive can comprise a hydrophilic polymer or amphiphilic polymer. The porous asymmetric membrane can be a flat membrane or hollow fiber.

A porous asymmetric membrane comprises a hydrophobic polymer comprising a poly(phenylene ether) or poly(phenylene ether) copolymer; and a polymer additive. A separation module can be fabricated from the porous asymmetric membrane. A method of forming the porous asymmetric membrane comprises: dissolving a hydrophobic polymer comprising a poly(phenylene ether) or poly(phenylene ether) copolymer and, a polymer additive in a water-miscible polar aprotic solvent to form a porous asymmetric membrane-forming composition; and phase-inverting the porous asymmetric membrane forming-composition in a first non-solvent composition to form the porous asymmetric membrane. The polymer additive comprises hydrophilic functional groups, copolymerized hydrophilic monomers, or blocks of hydrophilic monomer repeat units. For example, the polymer additive can comprise a hydrophilic polymer or amphiphilic polymer. The porous asymmetric membrane can be a flat membrane or hollow fiber.

An asymmetric membrane having a substantially non-porous surface layer is made by a method including: dissolving a poly(phenylene ether) copolymer in a solvent mixture including a first solvent and a second solvent to provide a membrane-forming composition; and phase-inverting the membrane forming composition in a first non-solvent to form the membrane comprising a substantially non-porous surface layer. The first solvent is a water-miscible polar aprotic solvent, and the second solvent is a polar solvent having two to eight carbon atoms.