The present invention is related to an osmosis membrane, specifically to a modified forward osmosis membrane and the method of preparing same. The inventive forward osmosis membrane has a modified membrane structure including a hydrophilic support mesh and a hydrophilic polymer membrane layer mixed antioxidant. The hydrophilic polymer membrane layer with antioxidant not only has high salt rejection, but also ensures high oxidation resistance under a strong oxidation environment, and can be used safely and stably. The inventive oxidation resistant forward osmosis membrane has the advantages of improving the efficiency of purifying and separating water, extending the service life, significantly reducing the operation cost of the forward osmosis membrane system. The inventive forward osmosis membrane can be applied in the industries of treatment of strong oxidation waste water, water purifying, filtration and purification of food and medicine filtering and so on.

Membranes suitable for use in membrane distillation are provided. Such membranes may include nano-fibrous layers with adjustable pore sizes. The membranes may include a hydrophobic nanofibrous scaffold and a thin hydrophilic protecting layer that can significantly reduce fouling and scaling problems.

A filter medium according to one embodiment of the present invention comprises: a first support having a plurality of pores; a nanofiber web comprising nanofibers disposed on upper and lower portions of the first support and forming a three-dimensional network structure, and a hydrophilic coating layer formed on at least a part of an outer surface of the nanofibers, wherein the hydrophilic coating layer is formed of a hydrophilic coating composition comprising a hydrophilic polymer compound having at least one functional group selected from a hydroxyl group and a carboxyl group and a crosslinking agent comprising at least one sulfone group; and a second support having a plurality of pores interposed between the first support and the nanofiber web.

A polysulfone membrane is modified so that monomers are wafted onto the surface of the membrane. The polysulfone membranes can be grafted by contacting the membrane with a grafting solution and exposing the membrane to electromagnetic radiation, typically within the ultraviolet portion of the spectrum. The monomers that are grafted are typically anionic or cationic. The grafted membranes can be used for filtering impurities, such as positively and negatively charged particles, from a liquid. Anionic membranes provide improved filtration of negatively charged impurities, while cationic membranes provide improved filtration of positively charged impurities.

[Problem] Provided is a semipermeable membrane that achieves chemical resistance (chlorine resistance, acid resistance, alkali resistance), membrane performance, and membrane strength by sulfonating a polyphenylene-based semipermeable membrane base material under specific conditions. [Solution] A polyphenylene-based semipermeable membrane that is composed of a material containing a polyphenylene-based resin, wherein the semipermeable membrane has a first surface of which at least a portion is sulfonated, and wherein, when concentration distribution of elemental sulfur derived from a sulfonic acid group is measured by elemental analysis in a cross section in a thickness direction of the semipermeable membrane, a ratio of a sulfonated layer obtained by the following expression is 50% or less: Ratio of Sulfonated Layer (%)=Sulfonated Layer Thickness/(Sulfonated Layer Thickness+Non-Sulfonated Layer Thickness)×100.

The invention relates to a polymeric fabric comprising an outer functional layer having hydrophobic and oleophobic characteristics made of a first compound, and a second functional layer having hydrophobic characteristics made of a second compound, wherein the first and the second compound differ from each other. Further the outer functional layer at least partly coats the second layer. Additionally, the invention relates to a method of producing a polymeric fabric and an apparatus for producing a polymeric fabric.

Disclosed are copolymers suitable for hydrophilically modifying the surface of porous fluoropolymer supports, for example, a copolymer of the formula (I) or (II): ##STR00001##
wherein Rf, Rh, Ra, Y, m, and n are as described herein. Also disclosed are a method of preparing the copolymers, a method of hydrophilically modifying porous fluoropolymer supports, hydrophilic fluoropolymer porous membranes prepared from the polymers, and a method of filtering fluids through the porous membranes.

The present invention provides a porous hollow fiber filtration membrane comprising a polysulfone-based polymer and hydrophilic polymer, the porous hollow fiber filtration membrane including a gradient asymmetric structure in which the average pore diameter of fine pores increases from the outer surface toward the inner surface, a content of the hydrophilic polymer in the membrane is 6.0 to 12.0% by mass, and a ratio of the content of the hydrophilic polymer in the outer surface to the content of the hydrophilic polymer in the membrane is 1.20 to 1.60.

Disclosed is the preparation of composite membranes formed by a tailored selective chemical modification of an ultra-thin nanoporous surface layer of a semi-crystalline mesoporous poly (aryl ether ketone) membrane with graded density pore structure. The composite separation layer is synthesized in situ on the poly (aryl ether ketone) substrate surface and is covalently linked to the surface of the semi-crystalline mesoporous poly (aryl ether ketone) membrane. Hollow fiber configuration is the preferred embodiment of forming the functionalized the poly (aryl ether ketone) membranes. Composite poly (aryl ether ketone) membranes of the present invention are particularly useful for a broad range of fluid separation applications, including organic solvent ultrafiltration and nanofiltration to separate and recover active pharmaceutical ingredients.

Water permeable coated substrates and filtration membranes are provided comprising: (a) a porous substrate; (b) an optional primer layer applied to a substrate surface (a), wherein the primer layer comprises silica and/or an organometallic compound; (c) a superhydrophilic coating layer applied to the porous substrate (a), or the primer layer (b), wherein the superhydrophilic layer comprises a superhydrophilic polymer or silicate; and (d)

an optional tie layer applied to the superhydrophilic coating layer (c), wherein the tie layer comprises silica and/or an organometallic compound. The water permeable coated substrates and filtration membranes may further include (e) an oleophobic coating layer applied to the superhydrophilic coating layer (c), or the tie layer (d), wherein the oleophobic coating layer comprises a fluoropolymer having reactive functional groups. Each layer of the coated substrate is covalently bonded to adjacent layers. Methods of separating an oil-in-water emulsion are also disclosed.