A method for in situ production of antimicrobial filtration membranes that uses self-assembly of surfactants such as block copolymers as a template. The mesophase structure (for example hexagonal or lamellar) can be determined, and membrane pore size can be controlled in the nanometer range, by changing the block copolymer and the amounts of the components such as the block copolymer, aqueous solution, monomer, crosslinker, and initiator. The monomer phase cures in the template and there is no need for organic solvents and coagulation bath or other post-modification. As-synthesized membranes were found to have pore sizes with a narrow size distribution in the range of 3-4 nm with a molecular weight cutoff of 1500 g/mol and displayed both excellent fouling resistance and high permeance of water, vastly outperforming a conventional NIPS UF membrane. The monomer can comprise a quaternary ammonium group so that the membrane is antibacterial. The block copolymer can comprise hydrophilic blocks which form the surfaces of the membrane pores, rendering them hydrophilic.

The present invention discloses a new method for synthesizing a high-quality inorganic film by microwave heating, which relates to the field of preparation of inorganic materials. The method for synthesizing a high-quality inorganic film by microwave heating in the present invention allows a fine design and control of the temperature increase process during microwave heating, wherein the matrix and the synthesis solution is put into the microwave reactor at first, the temperature interval between the initial temperature and the target temperature of the synthesis solution is then divided into multiple sections, each of which sets a temperature increase rate, and then when the temperature reaches the target temperature after the designed temperature increase process, the synthesis solution reacts for a period of time at the target temperature, finally the high-quality inorganic film can be obtained after the treatment of washing and drying. The inorganic film prepared by the method of the present invention is dense and thin.

The present invention provides a method for preparing a porous membrane of a fluorine-based resin having an improved shrinkage while maintaining excellent filtration efficiency and air permeability.

A hollow fiber membrane of the present invention is a hollow fiber membrane having an outer surface and an inner surface, wherein the inner surface has a zebra stripe pattern in which dense portions and porous portions are alternately formed in the longitudinal direction, and the outer surface has a maximum pore size of about 1 μm or less (≤about 1 μm), and wherein the hollow fiber membrane has a water permeability (flux) of ≥about 1,300 LMH/bar to ≤about 5,000 LMH/bar.

Disclosed are a method of manufacturing a polyethylene membrane comprising: stretching a polyethylene film in a first direction during a first stretching; attaching a plurality of rods on side edges of the polyethylene film; attaching a tape on the polyethylene film; stretching the polyethylene film having the rods attached thereto in a second direction during a second stretching; and annealing the polyethylene film after the second stretching. The second direction can be a transverse direction of the first direction, and the first stretching and the second stretching can be performed at the same (or higher) temperature and the same stretching speed as each other.

A method for in situ production of antimicrobial filtration membranes that uses self-assembly of surfactants such as block copolymers as a template. The mesophase structure (for example hexagonal or lamellar) can be determined, and membrane pore size can be controlled in the nanometer range, by changing the block copolymer and the amounts of the components such as the block copolymer, aqueous solution, monomer, crosslinker, and initiator. The monomer phase cures in the template and there is no need for organic solvents and coagulation bath or other post-modification. As-synthesized membranes were found to have pore sizes with a narrow size distribution in the range of 3-4 nm with a molecular weight cutoff of 1500 g/mol and displayed both excellent fouling resistance and high permeance of water, vastly outperforming a conventional NIPS UF membrane. The monomer can comprise a quaternary ammonium group so that the membrane is antibacterial. The block copolymer can comprise hydrophilic blocks which form the surfaces of the membrane pores, rendering them hydrophilic.

The present invention is concerned with a dielectric material comprising a fluoropolymer, wherein at least part of the crystalline region of the fluoropolymer is in the β-phase. The dielectric material of the present invention may show relaxor-like ferroelectricity. The present invention also relates to a novel method of producing such a material, and the use of such a material in a high energy density capacitor. The method comprises layering sheets of PVDF on one another and applying pressure to the multilayer under a temperature which is preferably within 40° C. of the temperature of fusion. Further, the film is preferably quenched.

Embodiments of the present disclosure generally relate to processes for forming functionalized membranes. In an embodiment, a process for forming a functionalized porous membrane is provided. The process includes introducing a porous membrane with an aqueous solution of a hydrophilic agent in a reaction zone, and operating the reaction zone under conditions to form the functionalized porous membrane, the conditions comprising heating the reaction zone to a temperature of about 95° C. or less.

A cross-linked polyimide of the reaction product of a crosslinking agent and a polyimide. The cross-linking agent having at least two cross-linking moieties and the polyimide has a plurality of polyimide chains having an aryl constituent with a moiety comprised of a reactive substituent. The polyimide has crosslinks from the reaction of the reactive substituent of the aryl constituents of the polyimide chains and the cross-linking moieties of the cross-linking agent. The cross-linking may be induced by thermally treating a mixture of the polyimide and crosslinking agent above about 150° C. to a temperature where the polyimide begins to decompose under an inert atmosphere. The membrane can be used for separations involving gases such as hydrogen and light hydrocarbons.

Described herein are articles for separating gases. The article includes a selective layer consisting of a crosslinked amorphous fluorinated copolymer containing one or more types of fluorinated ring monomers, with crosslinking between the fluorinated copolymer chains. The crosslinking improves the mechanical properties of the fluoropolymer, thereby permitting use of polymer types which would otherwise be excessively brittle. The resulting crosslinked polymer membranes have superior selectivity and reliability performance compared with previous compositions known to the art. Methods for making and using the article described are also provided.