The present invention pertains to a polycrystalline membrane containing metal nitride particles represented by the general formula MN.sub.x (where M is a metal element in which the Fermi energy is in a position higher than −4.4 eV vs L.V. and x is the range over which a rock salt-type structure can be assumed), in which the crystallite size determined by transmission electron microscopy is 10 nm or less, at least some of the crystallites have rock salt-type structure, and the crystallites exhibit (111) orientation but substantially do not exhibit (100) orientation. The present invention also pertains to a method for manufacturing a polycrystalline membrane, comprising forming, by sputtering, a polycrystalline membrane on a substrate having a temperature of less than 200° C., the polycrystalline membrane being represented by the general formula MN.sub.x and being such that at least some crystallites have a rock salt structure and the crystallites exhibit (111) orientation but essentially do not exhibit (100) orientation. The present invention provides a hydrogen-permeable TiN.sub.x microparticle membrane exhibiting a higher mixed hydride ion (H.sup.−)-electron conduction.

A support is a porous ceramic support for supporting a zeolite membrane. The hydraulic conductivity of the support is less than or equal to 1.1×10.sup.−3 m/s. In the support, the total content of alkali metal and alkaline earth metal in a surface part within 30 μm from a surface in a depth direction perpendicular to the surface is less than or equal to 1% by weight.

The present disclosure describes membrane compositions and methods for preparing membrane compositions. In particular, the methods employ a layer-by-layer approach to membrane preparation. The membrane compositions provide significantly enhanced membrane performance over existing commercial membranes, particularly in terms of permeability and selectivity.

Methods of fabricating a membrane comprising proteoliposomes having protein water channels are provided herein. The method may include providing a porous substrate, depositing a solution containing proteoliposomes on the porous substrate, and then contacting the porous substrate with an aqueous monomer solution and an organic monomer solution to form a selective layer on the porous substrate embedding the proteoliposomes. The method may include depositing the aqueous monomer solution, then the solution containing the proteoliposomes, then the organic monomer solution, to form the selective layer. The present disclosure also describes the membrane and a system operable to accommodate both methods.

An object of the present invention is to suppress a defect in a carbon membrane for fluid separation use with a dense carbon layer formed on a porous carbon support. The present invention is a carbon membrane for fluid separation use, including a dense carbon layer formed on a porous carbon support, wherein X<Y when the ratio of the content of silicon atoms to the total content of carbon atoms and silicon atoms at the center position in the membrane thickness direction of the porous carbon support is X (atomic %), and the ratio of the content of silicon atoms to the total content of carbon atoms and silicon atoms at the position of 3 μm from the interface between the porous carbon support and the dense carbon layer to the porous carbon support side is Y (atomic %).

A semipermeable membrane support having a thickness difference between measurement thickness at 0.80 N/cm.sup.2 and measurement thickness at 1.27 N/cm.sup.2 of 1.0 to 5.0% is excellent in adhesion to a semipermeable membrane and also adhesion between a raw water spacer and the semipermeable membrane and thereby can be expected to maintain high water permeability after modulation. A method of producing a semipermeable membrane support comprises the step of carrying out hot-press processing by using an elastic roll, which has(have) a hardness between a type A durometer hardness of 60 or more and a type D durometer hardness of 95 or less.

Durable asymmetric composite membranes consisting essentially of a film of cross-linked sulfonated poly(ether ether ketone) adhered to a sheet of hydrophilicitized microporous poly(ethylene) are disclosed. The membranes have application in the recovery of water from feed streams where the ability to clean in situ is desirable, for example in dairy processing. Methods of preparing cross-linked sulfonated poly(ether ether ketone) suitable for use as the rejection layer and hydrophilicitized sheets of microporous poly(ethylene) suitable for use as the support layer of such membranes are also disclosed.

A composite hollow fiber membrane according to one aspect of the present invention is provided with a semipermeable membrane layer, a support layer that has a hollow fiber shape and is porous, and an intermediate layer interposed between the semipermeable membrane layer and the support layer. The semipermeable membrane layer contains a crosslinked polyamide formed of a polyfunctional amine compound and a polyfunctional acid halide compound. The intermediate layer includes a layer portion made of the same material as the support layer, and the crosslinked polyamide impregnating the layer portion.

A reverse osmosis membrane is disclosed that has a hydrogel disposed on its surface, wherein the hydrogel is formed from a crosslinked polyvinylpyrrolidone or a copolymer of vinyl pyrrolidone. The hydrogel-coated membrane resists fouling by feed water contaminants. The permeate flux rate and salt rejection of the underlying membrane are not negatively affected by the hydrogel coating.

A monovalent selective ion exchange membrane is disclosed. The membrane includes a polymeric microporous substrate, a cross-linked ion-transferring polymeric layer on a surface of the substrate, and a charged functionalizing layer covalently bound to the ion-transferring layer. A method of producing a monovalent selective cation exchange membrane is also disclosed. The method may include chemically adsorbing a styrene intermediate layer to a cross-linked ion-transferring polymeric layer on a surface of a polymeric microporous substrate, chlorosulfonating the styrene intermediate layer to attach a sulfonyl chloride group layer, aminating the sulfonyl group layer to attach an amine group layer, and functionalizing the amine group layer with a charged compound layer to produce the cation exchange membrane. Water treatment systems including the monovalent selective cation exchange membrane and methods of facilitating water treatment including providing the monovalent selective cation exchange membrane are also disclosed.