B01D2323/08

System and method for producing hollow fibre membranes

The invention relates to an apparatus and a method for the manufacture of at least one hollow fiber membrane, wherein a spinning mass is extruded via a spinning unit to form a spinning thread and precipitated in a precipitation bath to form a hollow fiber membrane and the hollow fiber membrane is optionally rinsed in a rinsing bath, wherein furthermore the hollow fiber membrane is passed through at least one drying unit, wherein the drying unit comprises a pressure section which is constructed in such a way that a positive pressure compared with atmospheric pressure can be set in the pressure section, and at least part of the precipitating agent or rinsing agent contained in the at least one hollow fiber membrane (104) is separated from the at least one hollow fiber membrane.

Hollow-fiber membrane and hollow-fiber membrane module

A hollow-fiber membrane according to an aspect of the present disclosure contains a polytetrafluoroethylene or a modified polytetrafluoroethylene as a main component and has an average outer diameter of 1 mm or less and an average inner diameter of 0.5 mm or less. In a measurement of a heat of fusion of the polytetrafluoroethylene or the modified polytetrafluoroethylene with a differential scanning calorimeter, when the polytetrafluoroethylene or modified polytetrafluoroethylene is subjected to a first step of heating from room temperature to 365° C., a second step of cooling from 365° C. to 350° C., maintaining the temperature, subsequently cooling from 350° C. to 330° C., and further cooling from 330° C. to 305° C., and a third step of cooling from 305° C. to 245° C. at a rate of −50° C./min and subsequently heating from 245° C. to 365° C. at a rate of 10° C./min, a heat of fusion from 296° C. to 343° C. in the third step is 30.0 J/g or more and 45.0 J/g or less.

POROUS POLYMERIC CELLULOSE PREPARED VIA CELLULOSE CROSSLINKING

The invention relates to porous polymeric cellulose prepared via cellulose crosslinking. The porous polymeric cellulose can be incorporated into membranes and/or hydrogels. In preferred embodiments, the membranes and/or hydrogels can provide high dynamic binding capacity at high flow rates. Membranes and/or hydrogels comprising the porous polymeric cellulose are particularly suitable for filtration, separation, and/or functionalization media.

ANTIMICROBIAL FILTRATION MEMBRANES
20230001359 · 2023-01-05 · ·

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.

Biaxially oriented microporous membrane
11420416 · 2022-08-23 · ·

A microporous membrane is made by a dry-stretch process and has substantially round shaped pores and a ratio of machine direction tensile strength to transverse direction tensile strength in the range of 0.5 to 5.0. The method of making the foregoing microporous membrane includes the steps of: extruding a polymer into a nonporous precursor, and biaxially stretching the nonporous precursor, the biaxial stretching including a machine direction stretching and a transverse direction stretching, the transverse direction stretching including a simultaneous controlled machine direction relax.

METHOD FOR SYNTHESIZING HIGH-QUALITY INORGANIC FILM BY MICROWAVE HEATING
20220274067 · 2022-09-01 ·

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.

CHA zeolite membrane and method of preparing the same

Disclosed are a CHA zeolite membrane and a method of preparing the same, and more particularly, a CHA zeolite membrane having high capacity to separate CO.sub.2/N.sub.2 and CO.sub.2/CH.sub.4 even under wet conditions using a membrane produced using a synthetic precursor having a controlled ratio of Si and Al, a method of preparing the same, and a method of capturing and removing carbon dioxide using the membrane.

CONDUCTIVE MEMBRANE AND PREPARATION METHOD THEREOF

The present application discloses a conductive membrane and a preparation method thereof, which belong to the field of membrane separation technology. The conductive membrane provided by the present application includes a porous base layer film, a porous intermediate layer film, and a porous conductive layer film which are disposed layer by layer in sequence; wherein at least some holes of the base layer film are communicated with holes of the conductive layer film through holes of the intermediate layer film, and material of the intermediate layer film is the same as material of the base layer film and of the conductive layer film. Regarding the conductive membrane provided by the present application, it can be coupled with electrochemical technology, so that the membrane exhibits new excellent properties at the same time of playing separating characteristic.

Uniformly structured high-permeability microporous membrane for filtering and method for preparing the same, flat filtering element and gas filtering article

A microporous membrane for filtering and a method for preparing the same, a flat filtering element and a gas filtering article are disclosed. The microporous membrane is composed of following raw materials in parts by weight: 100-110 parts of polyethylene, 27-30 parts of acrylonitrile, 0.1-0.2 parts of dicumyl peroxide, 2-4 parts of plasticizer, 1-2 parts of antimonous oxide, 0.8-1 part of zinc borate, 1-2 parts of antioxidant, 0.8-2 parts of heat stabilizer, 1-2 parts of octylisothiazolinone, 1-3 parts of calcium propionate, 0.7-2 parts of triglycidyl isocyanurate, 4-6 parts of diacetone alcohol, 0.7-1 part of oleic diethanolamide, 0.5-1 part of sodium myrastate and 1-2 parts of glycolic acid.

Method for synthesis of flexible multifunctional high-voidage ultrathin PE membranes

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.