A method relating to a copolymer containing rigid polyamides blocks and flexible blocks including, relative to the total weight of the copolymer: from 55% to 90% by weight of flexible blocks, including at least 35% by weight from polyethylene glycol; from 10% to 45% by weight of rigid polyamide blocks, in which the mean carbon content of the repeating units of the polyamide blocks is greater than or equal to 7. A method also relating to a process for preparing such a copolymer, to a membrane including such a copolymer and to a process for preparing such a membrane.

[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 present disclosure discloses an asymmetric electrolyte membrane, a membrane electrode assembly including the same, a water electrolysis apparatus including the same and a method for manufacturing the same. More particularly, it discloses an asymmetric electrolyte membrane having a porous layer and a dense layer at the same time, a membrane electrode assembly including the same, a water electrolysis apparatus including the same and a method for manufacturing the same.

The disclosure provides a method for preparing a hollow fiber membrane by melt spinning-stretching and selective swelling, including: preparing a nascent hollow fiber by melt spinning in an inert gas protective atmosphere by using an amphiphilic block copolymer as a film forming material, and stretching the nascent hollow fiber in the cooling process, a stretch rate being controlled at 200-540 mm/min, and a stretch ratio being controlled at 150-600%; immersing the obtained hollow fiber in a swelling solvent, and treating the hollow fiber in a water bath at 65° C. for 1 h; and then transferring the hollow fiber into a long-chain alkane solvent, treating the hollow fiber at the same temperature for 1-12 h, and after the completion of the treatment, immediately taking out the hollow fiber and drying the hollow fiber to obtain the hollow fiber membrane with a bicontinuous porous structure. By combining the melt spinning-stretching and the selective swelling, the method of the disclosure can synchronously and continuously improve the permeability and selectivity of the hollow fiber membrane. The treatment in the long-chain alkane solvent can make the polar chain excessively enriched on the surface of the membrane migrate inward, thereby improving the performance of the hollow fiber membrane.

The disclosure provides a method for preparing a hollow fiber membrane by melt spinning-stretching and selective swelling, including: preparing a nascent hollow fiber by melt spinning in an inert gas protective atmosphere by using an amphiphilic block copolymer as a film forming material, and stretching the nascent hollow fiber in the cooling process, a stretch rate being controlled at 200-540 mm/min, and a stretch ratio being controlled at 150-600%; immersing the obtained hollow fiber in a swelling solvent, and treating the hollow fiber in a water bath at 65° C. for 1 h; and then transferring the hollow fiber into a long-chain alkane solvent, treating the hollow fiber at the same temperature for 1-12 h, and after the completion of the treatment, immediately taking out the hollow fiber and drying the hollow fiber to obtain the hollow fiber membrane with a bicontinuous porous structure. By combining the melt spinning-stretching and the selective swelling, the method of the disclosure can synchronously and continuously improve the permeability and selectivity of the hollow fiber membrane. The treatment in the long-chain alkane solvent can make the polar chain excessively enriched on the surface of the membrane migrate inward, thereby improving the performance of the hollow fiber membrane.

Provided is a membrane distillation system capable of real-time monitoring on membrane scaling, which includes: a raw water storage tank configured to store various kinds of fluid; a membrane distillation water treatment unit configured to receive raw water stored in the raw water storage tank to generate pure water, the membrane distillation water treatment unit having an inlet water chamber into which an inlet water flows from the raw water storage tank, a membrane for separating the inlet water in the inlet water chamber into a steam and a concentrated water, and a treated water chamber for receiving the steam separated by the membrane and concentrating the steam; and a membrane wetting detection unit disposed opposite to the membrane to detect a membrane wetting phenomenon and a membrane wetting location of the membrane by measuring a light passing through the membrane in real time.

Provided is a membrane distillation system capable of real-time monitoring on membrane scaling, which includes: a raw water storage tank configured to store various kinds of fluid; a membrane distillation water treatment unit configured to receive raw water stored in the raw water storage tank to generate pure water, the membrane distillation water treatment unit having an inlet water chamber into which an inlet water flows from the raw water storage tank, a membrane for separating the inlet water in the inlet water chamber into a steam and a concentrated water, and a treated water chamber for receiving the steam separated by the membrane and concentrating the steam; and a membrane wetting detection unit disposed opposite to the membrane to detect a membrane wetting phenomenon and a membrane wetting location of the membrane by measuring a light passing through the membrane in real time.

A forward osmosis membrane for seawater desalination and a method for preparing the same. The forward osmosis membrane has a composite membrane structure including a nonwoven fabric layer; a hydrophilic polymer layer; and a polyamide layer. The hydrophilic polymer layer formed on the nonwoven fabric layer facilitates an inflow of water from the feed water to the draw solution to enhance flux and realize high water permeability in the direction of osmosis. The polyamide layer not only secures contamination resistance and chemical resistance but also minimizes the back diffusion of salts of the draw solution in the direction of reverse osmosis. Hence, the forward osmosis membrane of the present invention is greatly useful for desalination of high-concentration seawater.

A nanocomposite blend membrane and fabrication methods for making the nanocomposite membrane are disclosed. The nanocomposite blend membrane can be utilized in fuel cells. The nanocomposite blend membrane may include a blend polymer with a first sulfonated polymer and a second sulfonated polymer, as well as sulfonated tungsten trioxide (WO.sub.3) nanoparticles.

A nanocomposite blend membrane and fabrication methods for making the nanocomposite membrane are disclosed. The nanocomposite blend membrane can be utilized in fuel cells. The nanocomposite blend membrane may include a blend polymer with a first sulfonated polymer and a second sulfonated polymer, as well as sulfonated tungsten trioxide (WO.sub.3) nanoparticles.