A spiral wound-type separation membrane module and a method for manufacturing the same are provided. The spiral wound-type separation membrane module according to an exemplary embodiment of the present invention is implemented by including an outlet pipe; a filter assembly wound in a spiral wound on the outlet pipe; and an adhesion portion in which part or all of a heat-adhesive yarn wound to surround the outer surface of the filter assembly in the longitudinal direction of the outlet pipe is melted and fixed to the filter assembly. According to the above, the spiral wound-type separation membrane module and the method for manufacturing the same can significantly reduce the defect rate and process time and simultaneously exhibit an eco-friendly effect during disposal after use.

The present invention relates to a separation membrane including a thermoplastic polymer selected from a cellulose ester and a polyamide, in which, when regions obtained by dividing a cross-sectional surface perpendicular to a longitudinal direction of the separation membrane into 5 at an equal interval are defined as regions 1 to 5, all the regions 1 to 5 have a number average pore diameter changing rate a of −0.25 to 0.25, and at least one of the regions 1 to 5 is a region P that satisfies conditions (a) and (b): (a) a value of area average pore diameter D.sub.s/number average pore diameter D.sub.n is 2.50 to 6.00; and (b) a number average W of fine pores that are located at a distance smaller than L.sub.a from a center of respective coarse pores is 10 to 30.

The problem of the present invention is to provide a novel polytetrafluoroethylene porous film having a small pore diameter, small film thickness, high porosity, and high strength, and a production method thereof.

The present invention provides a polytetrafluoroethylene porous film, wherein a bubble point in isopropyl alcohol (IPA) according to JIS K3832 is not less than 400 kPa, and a tensile strength based on JIS K6251 is not less than 50 MPa.

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.

Disclosed are a light-driven filtration antibacterial composite membrane and a preparation method and use thereof. The method for preparing the light-driven filtration antibacterial composite membrane includes: mixing dichloromethane and N,N-dimethylformamide to obtain a first solution; adding PCL particles to the first solution, and stirring until being uniform to obtain an electrospinning solution; adding a ZIF-8 powder to the electrospinning solution, and ultrasonically dispersing for at least 1 hour to obtain a PCL/ZIF-8 spinning solution; spraying the PCL/ZIF-8 spinning solution onto a PPCL@PDA/TAEG men-blown membrane to obtain the light-driven filtration antibacterial composite 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.

A composite media includes a stack with 20 or more layers, each layer including a substrate with a first major surface and an opposing second major surface; and a fiber layer deposited onto the first major surface of the substrate and including polymeric fibers with a diameter of 100 nm to 1.5 μm. Each fiber layer independently has a thickness of 5 μm to 100 μm, and each layer independently has a pore size of 0.1 μm to 10 μm. A filter may include a housing and the composite media disposed within the housing. The filter may be a syringe filter.

A polyolefin multilayer microporous membrane includes at least first microporous layers which form both surface layers of the membrane and at least a second microporous layer disposed between the both surface layers, wherein static friction coefficient of one of the surface layers of the polyolefin multilayer microporous membrane against another surface layer in a longitudinal direction (MD) is 1.1 or less, and wherein pore density calculated from an average pore radius measured by mercury porosimetry method and porosity, according to Formula (1) is 4 or more:
Pore density=(P/A.sup.3)×10.sup.4  (1)
wherein A represents the average pore radius (nm) measured by mercury porosimetry method and P represents the porosity (%).

The present invention relates to a composition for the manufacturing of a porous article, notably a membrane, which comprises a semi-crystalline polymer, an amorphous polymer and at least one water-soluble salt. The present invention also relates to a method for manufacturing said porous article and to its use for purifying fluid(s).

The invention relates to a vapor retarder membrane, intended to be used for improving the airtightness of a building or of a room, comprising at least one active layer having a water vapor permeability which increases with the surrounding relative humidity, said active layer comprising at least 90% by weight of a blend of ethylene/vinyl alcohol (EVOH) copolymer and of a copolyamide 6-6.6 (PA666), the latter having a melting point below 210° C.