The present invention aims to improve the separation selectivity for light gases such as hydrogen and helium. The gas separation membrane according to the present invention includes a porous support layer and a separation functional layer containing a cross-linked polyamide and laid on the porous support layer, wherein: the separation functional layer has a protuberance structure containing a plurality of protrusions and recesses; randomly selected 20 of the protrusions on the surface of the separation functional layer indented under a load of 3 nN and observed in pure water at 25° C. by atomic force microscopy give an average deformation of 5.0 nm or more and 10.0 nm or less; and they give a standard deviation of the deformation of 5.0 nm or less.

The present invention relates to a composite semipermeable membrane including: a support membrane including a base and a porous support layer; and a separation functional layer disposed on the porous support layer and including a crosslinked aromatic polyamide, in which the separation functional layer contains sulfo groups in an amount of 7.0×10.sup.−5 to 5.0×10.sup.−2 g/m.sup.2 and includes a structure represented by the formula 1.

Provided is a high permeance nanofiltration membrane with nanoring-like structure and preparation method thereof. The membrane includes a base film and a polyamide layer having nanoring-like structure morphology on its surface. The method includes: (1) formulating a piperazine nanoemulsion containing a surfactant, vegetable oil, piperazine and water; and (2) infiltrating a base film with the piperazine nanoemulsion, and removing excess droplets from the surface of the base film to obtain a treated base film; covering the surface of the treated base film with a solution of trimesoyl chloride in n-hexane to perform interfacial polymerization; and drying the resulting membrane. Introduction of nano-oil droplets into aqueous phase as templates to construct nanoring-like structure morphology on the surface of the polyamide layer significantly increases the specific surface area and free volume of the polyamide layer without losing the salt rejection rate of the membrane, thereby greatly improving its water permeance.

Described are wound-pleated filters and methods of preparing and using these filters.

The invention discloses a forward osmosis (FO) membrane containing silica nanoparticles having high permeate water flux and its manufacturing method. The FO membrane containing a plurality of silica nanoparticles comprises a substrate layer made of polysulfone and a polyamide layer disposed on the substrate layer. In the course of manufacturing the polyamide layer on the substrate layer by interfacial polymerization, the plurality of silica nanoparticles with different properties is added into the polyamide layer to obtain the FO membrane containing silica nanoparticles having high permeability and solute selectivity.

A composite semipermeable membrane includes a porous support membrane, a separation functional layer containing a polyamide disposed on the porous support membrane, and a coating layer disposed on the separation functional layer, wherein a water contact angle of a surface of the coating layer is 40° or less, and a protein adsorption force of the surface of the coating layer is 0.4 nN or less.

Water permeable membranes and methods of preparation are described. The water permeable membrane can comprise a porous support, and a polyamide layer comprising a crosslinked polyamide on a surface of the porous support, wherein the polyamide layer further comprises nanoparticles and a hydrophilic additive, and wherein the hydrophilic additive covalently bonds to the crosslinked polyamide. The crosslinked polyamide can be interfacially polymerized on the porous support. Methods for desalinating water, performing dialysis, or performing pervaporation using the water permeable membranes are disclosed.

The invention relates to the field of industrial wastewater treatment, and particularly discloses a nanofiltration membrane for treating printing and dyeing wastewater and its preparation method. The preparation method comprises the following steps: S1, pouring an aqueous solution containing m-phenylenediamine, camphorsulfonic acid and triethylamine onto the surface of a polysulfone ultrafiltration membrane, setting still for 10 s to 30 s, and then removing the excess aqueous solution from the surface; S2, pouring an organic solution containing trimesoyl chloride and an interface auxiliary polymerization agent onto the surface of the membrane obtained in step S1, reacting for 5 s to 20 s, and then removing the excess solution from the surface; and S3, setting the membrane obtained in step S2 still and then carrying out heat treatment and water rinsing on the membrane in sequence, thus obtaining the nanofiltration membrane.

The invention relates to the field of biomimetic membranes with artificial water channels, notably the use thereof in the context of the production and management of drinking water. The present invention relates to a biomimetic membrane with artificial water channels, the method of synthesis thereof, as well as the use thereof for desalination of brackish water and seawater, production of ultra-pure water or filtration of contaminants.

The present disclosure relates to a method of preparing a thin film composite layer immobilizing vesicles incorporating a transmembrane protein on a porous substrate membrane, comprising providing an aqueous solution comprising the vesicles and a di-amine or tri-amine compound, covering the surface of a porous support membrane with the aqueous solution, applying a hydrophobic solution comprising an acyl halide compound, and allowing the aqueous solution and the hydrophobic solution to perform an interfacial polymerization reaction to form the thin film composite layer.