Abstract: The present invention relates to a damage inspection method for a reverse osmosis membrane, in which at least one of: presence or absence of physical damage; and a degree of physical damage in a reverse osmosis membrane is inspected based on presence or absence of a stained area on at least a permeate side of a stained membrane obtained by supplying a water-to-be-treated including a staining agent to the reverse osmosis membrane to stain the reverse osmosis membrane.

Abstract: The present invention provides a method for analyzing a halogenated structure in a composite semipermeable membrane. The method for analyzing a composite semipermeable membrane according to the present invention includes: a step A for immersing the composite semipermeable membrane in a solution containing alkali and at least one of nicotinamide and a derivative thereof; and a step B for performing fluorescence analysis on the solution obtained in step A.

Abstract: The present invention relates to a composite semipermeable membrane including: a supporting membrane including a substrate and a porous supporting layer; and a separation functional layer disposed on the porous supporting layer, in which the separation functional layer includes: a crosslinked polyamide; and a hydrophilic polymer which is a polymer of a monomer having an ethylenically unsaturated group, and a surface of the separation functional layer has a ratio of the number of oxygen atoms to the number of nitrogen atoms (O/N ratio), both determined by X-ray photoelectron spectrometry, of 1.5-10, and a standard deviation of the O/N ratio of 0.15 or larger.

Abstract: An object of the present invention is to provide a separation membrane having high permeability and selective removability of divalent/monovalent ions. The separation membrane of the present invention includes a supporting membrane and a separation functional layer formed on the supporting membrane, in which the separation functional layer contains a polymerized product of a polyfunctional amine with a polyfunctional acid halide, the polyfunctional amine contains a polyfunctional aliphatic amine as a main component, the separation functional layer has a hollow protuberant structure, and the separation functional layer has a relative surface area of 1.1-10.0.

Abstract: This composite semipermeable membrane is provided with: a porous supporting membrane that comprises a base and a porous supporting layer; and a separating function layer that is provided on the porous supporting layer. With respect to this composite semipermeable membrane, the standard deviation of pore radius of the separating function layer as determined by positron annihilation lifetime measurement is 0.025 nm or less.

Abstract: An object of the present invention is to provide a composite semipermeable membrane which has a high permeation rate and high salt removal performance and is excellent in terms of performance stability during long-term operation. The composite semipermeable membrane of the present invention includes: a supporting membrane including a substrate and a porous supporting layer; and a separation functional layer disposed on the porous supporting layer, the separation functional layer includes a crosslinked polyamide and a hydrophilic polymer having an acidic group, and in the separation functional layer, a ratio of (molar equivalent of amino groups)/(molar equivalent of amide groups) is 0.18 or less.

Abstract: A composite semipermeable membrane includes a porous supporting membrane and a separation functional layer, in which, in cross-sections having a length of 2.0 ?m in a membrane surface direction, the average number density of projections in the separation functional layer which have a height of one-fifth or more of the 10-point average surface roughness is 10.0-30.0 projections/?m and the projections have an average height less than 100 nm, and in which a water production rate and a salt rejection are predetermined values or more after an aqueous solution is passed through under certain conditions.

Abstract: The present invention relates to a composite semipermeable membrane including: a supporting membrane including a substrate and a porous supporting layer; and a separation functional layer disposed on the porous supporting layer, in which the separation functional layer includes: a crosslinked polyamide; and a hydrophilic polymer which is a polymer of a monomer having an ethylenically unsaturated group, and a surface of the separation functional layer has a ratio of the number of oxygen atoms to the number of nitrogen atoms (O/N ratio), both determined by X-ray photoelectron spectrometry, of 1.5-10, and a standard deviation of the O/N ratio of 0.15 or larger.

Abstract: A method of producing a composite semipermeable membrane includes forming a porous support by applying polymer solution forming a first layer and polymer solution forming a second layer on a substrate; immersing the substrate in a non-solvent; and forming a separation functional layer the porous support membrane using an aqueous solution containing polyfunctional amine and an organic solvent solution containing a polyfunctional acid halide; wherein the first layer is formed to contact the substrate; the second layer is formed to contact the separation functional layer; the polymer solutions contain polysulfone; the concentration of polysulfone in a polymer solution A is 12% or more and 18% or less by weight; the concentration of polysulfone in a polymer solution B is 14% or more and 25% by weight or less; and the polysulfone concentration of the polymer solution B is greater than the polymer concentration of the polymer solution A.

Abstract: This composite semipermeable membrane is provided with: a porous supporting membrane that comprises a base and a porous supporting layer; and a separating function layer that is provided on the porous supporting layer. With respect to this composite semipermeable membrane, the standard deviation of pore radius of the separating function layer as determined by positron annihilation lifetime measurement is 0.025 nm or less.

Abstract: An object of the present invention is to provide a separation membrane having high permeability and selective removability of divalent/monovalent ions. The separation membrane of the present invention includes a supporting membrane and a separation functional layer formed on the supporting membrane, in which the separation functional layer contains a polymerized product of a polyfunctional amine with a polyfunctional acid halide, the polyfunctional amine contains a polyfunctional aliphatic amine as a main component, the separation functional layer has a hollow protuberant structure, and the separation functional layer has a relative surface area of 1.1-10.0.

Abstract: An object of the present invention is to provide a composite semipermeable membrane which has a high permeation rate and high salt removal performance and is excellent in terms of performance stability during long-term operation. The composite semipermeable membrane of the present invention includes: a supporting membrane including a substrate and a porous supporting layer; and a separation functional layer disposed on the porous supporting layer, the separation functional layer includes a crosslinked polyamide and a hydrophilic polymer having an acidic group, and in the separation functional layer, a ratio of (molar equivalent of amino groups)/(molar equivalent of amide groups) is 0.18 or less.

Abstract: The present invention provides a separation membrane that is usable at a high temperature and a high pressure. The solvent-resistant separation membrane of the present invention has an average pore diameter of the separation membrane surface of 0.005 to 1 ?m and includes a portion where a degree of cyclization (I1600/I2240) as measured by the total reflection infrared absorption spectroscopy is 0.5 to 50.

Abstract: The present invention provides a separation membrane that is usable at a high temperature and a high pressure. The solvent-resistant separation membrane of the present invention has an average pore diameter of the separation membrane surface of 0.005 to 1 ?m and includes a portion where a degree of cyclization (I1600/I2240) as measured by the total reflection infrared absorption spectroscopy is 0.5 to 50.

Abstract: Provided is a composite semipermeable membrane, comprising: a microporous support membrane which comprises a substrate and a porous support, and a polyamide separation functional layer formed on the microporous support membrane, wherein the polyamide has an irreversible heat absorption, which is measured using temperature modulated DSC, of 275 J/g or more at a temperature in the range of ?20 to 150° C. in the first heating process. Provided is a high-performance composite semipermeable membrane having high chemical durability, high water permeation and high rejection.

Abstract: The present invention provides a composite semipermeable membrane achieving high permeate amount and having high capability to inhibit adhesion of foulants to the membrane surface. The present invention relates to a composite semipermeable membrane including: a supporting membrane which includes a substrate and a porous supporting layer; and a polyamide separation functional layer formed on the porous supporting layer, in which an acidic group-containing hydrophilic polymer is introduced onto the surface of the separation functional layer via amide linkage, and relates to a method for producing such a composite semipermeable membrane.

Abstract: A composite semipermeable membrane includes a porous supporting membrane and a separation functional layer, in which, in cross-sections having a length of 2.0 ?m in a membrane surface direction, the average number density of projections in the separation functional layer which have a height of one-fifth or more of the 10-point average surface roughness is 10.0-30.0 projections/?m and the projections have an average height less than 100 nm, and in which a water production rate and a salt rejection are predetermined values or more after an aqueous solution is passed through under certain conditions.

Abstract: A composite semipermeable membrane includes a porous support membrane made of a substrate and a porous support layer and a polyamide separation-functional layer disposed on the porous support layer, wherein the zeta potential of the separation-functional layer at pH 6 is ?20 mV or lower, and the zeta potential difference between potentials of the separation-functional layer at pH 10 and pH 3 is 25 mV or smaller, and has high water permeability and high salt rejection performance and high acid/alkali durability.

Abstract: A composite semipermeable membrane in which a polyamide separation functional layer is formed on a porous support membrane includes a substrate and a porous support, wherein a standard deviation of a membrane thickness of the separation functional layer is 2.00 nm or less.

Abstract: Disclosed herein are a composite semipermerable membrane and a method for producing the same. The composite semipermeable membrane comprises a microporous support membrane and a separation functional layer provided on the microporous support membrane, wherein the separation functional layer contains a condensation product produced by condensation of at least one selected from the group consisting of ions of trialkoxysilanes each having an imidazolium group and a conjugated base of a polymer having at least one acidic group. The composite semipermeable membrane achieves excellent selective separation of divalent ions over monovalent ions, and is suitable for use in various water treatment fields such as seawater desalination and drinking water production.