A provided stretched porous polytetrafluoroethylene membrane has a node-fibril structure including a plurality of nodes and a fibril connecting the plurality of nodes. A ratio of an average length of the plurality of nodes in a thickness direction of the stretched porous polytetrafluoroethylene membrane to a thickness of the stretched porous polytetrafluoroethylene membrane is 10% or more. The above stretched porous polytetrafluoroethylene membrane is less likely to suffer breakage. In the above stretched porous polytetrafluoroethylene membrane, assuming that there is a cuboid region having an upper surface and a lower surface respectively positioned at one membrane surface and the other membrane surface of the stretched porous polytetrafluoroethylene membrane, the number of the nodes included in the region may be 4 or less per micrometer thickness, the upper surface and the lower surface each having dimensions of 280 μm×280 μm.

Provided is a porous membrane including polytetrafluoroethylene and/or modified polytetrafluoroethylene having a small pore diameter, thin film thickness, high porosity, and high strength; and a method for manufacturing the same. The porous membrane including polytetrafluoroethylene and/or modified polytetrafluoroethylenehas bubble point of isopropyl alcohol according to JIS K3832 of 600 kPa or more, and tensile strength according to JIS K6251 of 90 MPa or more.

The present invention relates to a lipophilic and hydrophobic nanofiber membrane and a method of preparing the same. The lipophilic and hydrophobic nanofiber membrane according to an exemplary embodiment may be compressed at a pressure of 10 kPa to 100 kPa and may have an average thickness of 10 μm to 1,500 μm.

Embodiments described herein relate generally to durable graphene oxide membranes for fluid filtration. For example, the graphene oxide membranes can be durable under high temperatures non-neutral pH, and/or high pressures. One aspect of the present disclosure relates to a filtration apparatus comprising: a support substrate, and a graphene oxide membrane disposed on the support substrate. The graphene oxide membrane has a first lactose rejection rate of at least 50% with a first 1 wt % lactose solution at room temperature. The graphene oxide membrane has a second lactose rejection rate of at least 50% with a second 1 wt % lactose solution at room temperature after the graphene oxide membrane is contacted with a solution that is at least 80° C. for a period of time.

The present invention discloses a Fe—Al-based metal membrane and preparation method thereof, which relate to the technical field concerning gas-solid separation under high-temperature, low-pressure working conditions, and mainly address the defects of conventional metal filter elements in the prior art such as high filtration resistance and low flux under low-pressure working environments. The preparation method of the present invention comprises the steps of: stirring and defoaming a mixture composed of a Fe—Al-based metal powder and an organic-additive-added water-based solvent, thus obtaining a cast slurry; casting a uniform membrane layer on a metal substrate layer having a required thickness on a casting machine, and performing drying treatment on it, thus obtaining a membrane green body; and, placing the dried membrane green body in a sintering furnace for degreasing, sintering, and alloy phase ordering treatments, respectively, thus obtain a prepared Fe—Al-based metal 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.

Embodiments described herein relate generally to durable graphene oxide membranes for fluid filtration. For example, the graphene oxide membranes can be durable under high temperatures non-neutral pH, and/or high pressures. One aspect of the present disclosure relates to a filtration apparatus comprising: a support substrate, and a graphene oxide membrane disposed on the support substrate. The graphene oxide membrane has a first lactose rejection rate of at least 50% with a first 1 wt % lactose solution at room temperature. The graphene oxide membrane has a second lactose rejection rate of at least 50% with a second 1 wt % lactose solution at room temperature after the graphene oxide membrane is contacted with a solution that is at least 80° C. for a period of time.

A composite pervaporation laminate incorporates a thin hydrophilic film laminated on a formable macroporous support layer. The method for making the membrane involves solution casting a thin film on a carrier substrate and transferring the said film onto a macroporous support by hot pressing, such as by decal transfer. Ultra-thin defect-free film, such as less than 5 micrometers, are laminated using this method to achieve very high-water transmission rates and very low or zero gas permeation. The membrane can then be formed into a three-dimensional structure by pleating or corrugating to increase the surface area. The membrane can be used as spacers in an ERV application.

A reverse osmosis membrane of the present invention includes a porous support substrate (2) and a separation active layer (3) formed on a surface of the porous support substrate (2) and formed of a carbon film containing organized carbon.

Embodiments described herein relate generally to graphene oxide membranes for fluid filtration and more specifically to graphene oxide membranes having tunable permeability, rejection rate, and flux. Some embodiments of the graphene oxide membranes disclosed herein are characterized as having a flux of at least about 2.5×10.sup.−4 gallons per square foot per day per psi with a 1 wt % lactose solution at room temperature, and a lactose rejection rate of at least 50% with a 1 wt % lactose solution.