472results about How to "High permeation flux" patented technology

The invention relates to a high-water-flux forward-osmosis composite membrane and a preparation method thereof. The forward-osmosis composite membrane is a polysulfone-sulfonated polysulfone-inorganic filler blended/polyamide composite membrane. A traditional osmosis membrane is generally applied to a reverse-osmosis system, and if the traditional osmosis membrane is used in a forward-osmosis process, the water flux of osmosis is far lower than a theoretical value since the traditional osmosis composite membrane is large in thickness, the hydrophilicity of a supporting layer of a polyamide layer is poor so as to cause serious inner concentration polarization. The preparation method comprises the following steps: blending a polymer with a modifier to form film casting liquid; after scraping or leveling, performing non-solvent coagulating bath with water; by a phase-inversion method, preparing a polysulfone ultrafiltration membrane with good hydrophilicity, high porosity, uniform surface pore structure and narrow pore diameter distribution; and in a clean environment and at room temperature, airing the polysulfone membrane till the surface is dry, and growing a polyamide active layer on the surface of the polysulfone membrane by an interfacial polymerization method, thereby obtaining the forward-osmosis composite membrane with good hydrophilicity, high porosity, low thickness and high mechanical strength. The high-water-flux forward-osmosis composite membrane disclosed by the invention has the advantages that not only the osmosis flux is high, but also the reverse leakage of an extraction medium is low, and the selective permeability is good.

The invention relates to an asymmetrically-structural ceramic ultrafiltration membrane and a preparation method thereof, wherein the preparation method thereof comprises the steps: dispersing one-dimensional fibrous material in sol and sufficiently mixing the material with the gel; by adding deionized water, controlling the weight ratio of gel particle to fiber in membrane preparing solution in a range from 0.01 to 0.4, adjusting pH value of the solution, adding dispersing agent, thickening agent and defoaming agent to formulate the membrane preparing solution, coating membrane on a porous support body and drying the porous support body to form a transition layer; coating the gel-containing membrane preparing solution on the surface of the transition layer, air-drying, oven-drying and roasting the wet membrane, and naturally cooling the membrane to result in the asymmetrically-structural ceramic ultrafiltration membrane. Since the transition layer is composed of fiber and sintering is promoted through the gel, resistance of the transition layer is advantageously lessened and interior combination strength of the transition layer is enhanced; the fiber-constructed transition layer divides large pores into small pores to provide larger total porosity and flowing pore channel, thus high permeation flux is maintained while high selectivity is obtained.

The invention discloses a preparation method for a polyether sulfone/graphene oxide composite ultrafiltration membrane. The preparation method comprises the following steps of ultrasonically dispersing the graphene oxide into an organic solvent to form uniform and stable dispersing liquid; adding polyether sulfone and additive into the dispersing liquid; stirring, dissolving, standing and defoaming to form uniform and stable casting membrane liquid; pouring the casting membrane liquid on a glass plate; scraping the membrane; and immersing into coagulating bath at room temperature to obtain the polyether sulfone/graphene oxide composite ultrafiltration membrane after the membrane is removed automatically, wherein the casting membrane liquid comprises the following components as per mass percentage concentration: 15 to 21 percent of polyether sulfone, 1 to 2 percent of pore-forming agent and 0.5 to 4.0 percent of graphene oxide. The polyether sulfone/graphene oxide composite ultrafiltration membrane has high hydrophilcity, high porosity, static resistance, elasticity and the like and improves the flux of pure water, retention rate, pollution resistance, mechanical property and the like.

The present invention discloses a plant polyphenol modified polymer membrane as well as a preparation method and application thereof, in particular relates to the field of modified polymer membranes with anti-fouling properties. In the prior art, due to low surface energy of the polymer membrane, the polymer membrane is susceptible to contamination with proteins, oils and the like and causes a series of temporary or permanent pollution problems. The polymer membrane provided by the invention utilizes the super-strong adhesive ability of plant polyphenols and the coordination of polyphenols andmetal ions to build a hydrophilic coating on the surface of a hydrophobic polymer membrane. The polymer membrane provided by the invention has the advantages of simplicity, high efficiency, mild reaction condition and strong practicability. The controllable hydrophilic modification of a hydrophobic polymer can be realized by changing the conditions of the dip-coating time, the concentration of aplant polyphenol mixed solution, the pH, the temperature and the like, and a high permeation flux can be maintained in the course of cross-flow continuous work, so that the polymer membrane has a verygood application prospect in the field of water treatment. The invention also opens up an effective way, which is simple and easy to operate and has strong universality, for modification of polymer membranes under mild conditions.

The invention relates to a preparation method for a polydopamine-modified polyamide composite forward osmosis membrane. The preparation method comprises the following steps: (1) a supporting layer is prepared; (2) the surface of the supporting layer is modified by polydopamine coating; (3) a polyamide separation layer is prepared on the surface of the modified supporting layer, and thereby the polydopamine-modified polyamide composite forward osmosis membrane is obtained. The polydopamine-modified polyamide composite forward osmosis membrane prepared by the preparation method has the advantages of hydrophilcity, large pure water permeation flux and small reverse salt diffusion flux, and is applicable to the field of water treatment such as sea water desalination.

The invention relates to a preparation method of a layer-by-layer self-assembly metal-organic framework composite film. Polyethyleneimine (PEI) with positive charges, a methanol solution containing ZIF-8 and polyacrylic acid (PAA) with negative charges deposit on the surface of a polyether sulfone (PES) film layer by layer, ZIF-8 is wrapped in PEI and PAA through the electrostatic repulsion effect of the opposite charges, and a layer structure is formed on the surface of the PES film. By preparing the methanol solution containing ZIF-8, through the layer-by-layer self-assembly technology, ZIF-8 is successfully loaded on the surface of the PES film, the loading capacity of the PES film is maximized, and the composite film material with high permeation flux under no permselectivity compromise is successfully prepared.

The invention discloses a low-pressure high-flux chlorine-containing polymer nanofiltration membrane with a stable separation layer and a preparation method thereof. The nanofiltration membrane comprises a macroporous support layer and a dense function layer, wherein the macroporous support layer and the dense function layer are connected with each other by virtue of a C-N bond; the dense function layer is made of a positive, charged or amphoteric ionic cross-linking polyamine compound; the macroporous support layer is made of a chlorine-containing polymer. The preparation method of the filtration membrane comprises the following steps: firstly coating the surface of a chlorine-containing polymer ultrafiltration membrane with the polyamine compound, carrying out heat treatment, washing the ultrafiltration membrane, then dipping the ultrafiltration membrane in a mixed solution of a cross-linking agent and a charge reagent and carrying out heat treatment again. The membrane flux of the prepared polymer nanofiltration membrane can reach 60L/m<2>.h under the pressure of 0.3MPa; the retention rate on micromolecule dye and high-valence inorganic salt can reach 90%; the chlorine-containing polymer nanofiltration membrane can be in a flat fiber ultrafiltration membrane form or a hollow fiber ultrafiltration membrane form, and has good practical prospect.

A composite semipermeable membrane which combines the high ability to reject salts and a high permeation flux and is especially excellent in the ability to reject uncharged substances, and a process for producing the semipermeable membrane are disclosed. The process comprises forming on a surface of a porous supporting film a thin film comprising a polyamide resin obtained by reacting a polyfunctional amine ingredient with a polyfunctional acid ingredient in the presence of at least an alkali metal hydroxide and an organic acid.

The invention provides a preparation method of an amino-modified graphene oxide composite positive permeable film. The method is characterized by comprising the following specific steps: mixing graphene oxide, dimethyl formamide, organic amine and dicyclohexyl carbimide, and performing ultrasonic treatment; reacting for 40-50 hours at the temperature of 100-150 DEG C; adding absolute ethyl alcohol, and standing and filtering to obtain a precipitate; washing and drying the precipitate to obtain amino-modified graphene oxide; mixing the amino-modified graphene oxide with a solvent, performing ultrasonic treatment, and adding an additive and a film formation polymer into a mixed solution to prepare a casting film solution; de-foaming to prepare a base film through a phase inversion method, and immersing the base film in pure water for later use; and pouring a metaphenylene diamine solution and trimesoyl chloride to the surface of the base film, performing a contact reaction, washing the surface of the film with an organic solvent, and drying the film to obtain the amino-modified graphene oxide composite positive permeable film. The amino-modified graphene oxide composite positive permeable film is high in mechanical strength, high in chemical stability, large in permeation flux of the pure water, and high in salt rejection rate.

The invention belongs to the technical field of chemical equipment, and relates to a method for producing hydrogen through coupled catalytic reforming and membrane separation reaction, and a device thereof, in particular to a method for producing hydrogen through fluidized-bed methane steam reforming, and a device thereof, which apply to the fields of petroleum, chemical industry and fuel cells. A main structure comprises a feed gas inlet, a pre-distribution chamber, a gas distribution plate, a palladium membrane component, a catalyst bed layer, a sampling port, a fluidized-bed reaction-zone bed body, a metal connection tube, a heating system, a hydrogen duct, an expansion section, a super pure hydrogen outlet, a vacuum pump, a backpressure valve, a liquid rotor flow meter, a water pump, an exhaust gas outlet, a heat exchanger, a gas rotor flow meter, a gas pump and a preheater, wherein the components are in gas-liquid communication and organic coordination to form a methane steam reforming hydrogen production device or reactor with a hydrogen selective membrane fluidized bed, and the top of the fluidized-bed reaction-zone bed body is sealed by adopting a cover-type structure. The invention has the advantages of simple process, low investment in equipment, good membrane separation performance and high hydrogen production rate.

The invention involves a preparation method used for separating the polyvinyl alcohol/chitosan mixing film of methanol/dimethyl carbonate, the preparation process is as follows: 1) dissolving the polyvinyl alcohol with the deionized water as solvent in 80 ~ 100 degree C and gaining uniform casting film solution which polyvinyl alcohol concentration is 5wt%; 2) dissolving the chitosan with the glacial acetic acid and deionized water as solvent in 20-40DEG C and gaining uniform casting film solution which chitosan concentration is 1wt%; 3) according certain radio mixing the ratio of PVA and chitosan solution uniformly and debubbling; 4) making film on the glass plate with casting method; 5) thermal treating the film 2~4 hours in 120 ~ 150 degree C. Compared with traditional separation methods, the method has some characteristics such as high one-time separation degree, simple precess, low energy consumption and pollution-free.

The invention relates to a metal organic compound filled cross-linked polysiloxane pervaporation membrane and a preparation method thereof, and belongs to the field of membrane separation. The method comprises the following steps of: mixing a cross-linking agent, a catalyst, linear polysiloxane and a solvent, reacting to generate prepolymer, adding a metal organic compound, and performing cross-linking reaction to obtain a membrane casting solution; and coating the membrane casting solution on a macromolecular porous bottom membrane, drying, and heating to obtain a product, namely the metal organic compound filled cross-linked polysiloxane pervaporation membrane. The metal organic compound filled cross-linked polysiloxane pervaporation membrane prepared by the method has the characteristics of high permeation flux, good separation effect, high strength, stable structure and the like, is suitable for removing low-concentration organic compounds from water, and is particularly suitable for separating low molecular alcohol from a fermentation solution.

The invention discloses a preparation method for a temperature sensitive response type intelligent ceramic composite membrane and a product. The product is obtained by chemical graft copolymerization of N-isopropyl acrylamide on the surface of a ceramic membrane. The invention takes the ceramic membrane as a basement membrane, takes the N-isopropyl acrylamide as a functional monomer, and adopts a method of chemical graft to prepare the temperature sensitive response type intelligent ceramic composite membrane. The prepared intelligent ceramic composite membrane can overcome the disadvantage of low mechanical strength of an intelligent membrane prepared taking an organic membrane as the basement membrane, has favorable chemical stability, long service life and the environmental sensitivity of a graft monomer, and is easy to disinfect and clean.

The invention discloses a Al2O3-SiO2 ceramic membrane which comprises a support body and a separation layer and is characterized in that the separation layer is prepared by coating a membrane making solution comprising nano SiO2, PVA (polyvinyl acetate), glycerol and water on the inner surface of the support body by adopting a melting-sol-gel process. The invention also discloses a preparation method of the Al2O3-SiO2 ceramic membrane, and the method comprises the following steps of: preparing the nano Al2O3 support body by adopting a blended particle sintering process; and coating the membrane making solution comprising the nano SiO2, the PVA, the glycerol and the like on the inner surface of the support body by adopting the melting-sol-gel process to form the Al2O3-SiO2 ceramic membrane. By adopting the technical scheme, the Al2O3-SiO2 ceramic membrane has the characteristics of low cost, simpleness and easiness for acquisition, increased membrane flux, high mechanical strength, pollution resistance, uniform membrane aperture, thin membrane wall, large permeation flux, raw material saving, easy realization of miniaturization and simplified structure of separation equipment, and the like.

The invention relates to a thermal stable and super-hydrophobic ceramic-carbon nanotube composite membrane and application of membrane distillation water treatment thereof, and belongs to the technical field of inorganic membranes. The composite membrane is prepared by the following steps of adopting a chemical vapor deposition method, using a ceramic hollow fiber membrane as a carrier, changing the different preparation conditions, such as a loading amount of a catalyst, reaction temperature and reaction time, and controlling the structure, loading amount and load state of the carbon nanotube, so as to obtain the ceramic-carbon nanotube hollow fiber composite membrane with different structures and properties. The composite membrane has the advantages that by regulating and optimizing the preparation conditions, the thermal stable and super-hydrophobic composite membrane with a carbon nanotube complete covering structure is obtained; the seawater freshening, high-salt wastewater zero drainage, and other wastewater high-efficiency treatment, such as electroplating heavy metal wastewater, dyeing and printing wastewater and antibiotic wastewater, can be realized via the composite membrane; and the good membrane distillation property is realized.

A high-flux pressure resistant hyperfiltration membrane in layered pore structure is characterized in that the support layer of the hyperfiltration membrane is provided with macropores parallel with the surface of the hyperfiltration membrane, and the macropores are in multilayer structure. The high-flux pressure resistant hyperfiltration membrane is prepared by using the following method: (1) membrane solution is prepared by using a polymer, a magnetic material, an additive and a solvent; the magnetic material and the polymer account for 8 percent to 50 percent of the membrane solution by mass, and the magnetic material, and the combination of the magnetic material and the polymer account for 30 percent to 99 percent by weight; the additive accounts for 2 percent to 15 percent of the membrane solution by mass; (2) a magnetic field with the direction of lines of magnetic force parallel with the surface of the membrane is applied during evaporation and gelation in manufacturing of the membrane, and the intensity of the magnetic field ranges from 100 gauss to 18000 gauss. The infiltration flux of the hyperfiltration membrane in layered pore structure is high and no leakage occurs during pressurization and running. The hyperfiltration membrane can be used directly, and can be used as the multihole supporting material of a composite membrane.

The invention discloses an organic-inorganic three-layer composite film and a preparation method thereof, and belongs to the field of the preparation of film materials. The composite film comprises asupporting layer, a middle transition layer and a surface active layer, wherein the supporting layer adopts an inorganic film, with the surface average pore size being 10 to 800 nm; the middle transition layer adopts organic polymer, with the mass fraction being 1 to 10 percent, and the surface average pore size being 5 to 80 nm; the surface active layer adopts silicone rubber PDMS, with the filmlayer thickness being 1 to 10 micrometers. The organic-inorganic three-layer composite film takes an organic polymer film with controllable thickness and surface pore size as a middle transition layer, can optimally regulate the uniformity and thickness of the surface active layer of the composite film and the bonding strength between the dense surface active layer and the middle transition layerand between the inorganic film supporting layer and middle transition layer by controlling the viscosity of PDMS coating fluid. The composite film is large in permeation flux and high in separation factor, and the surface active layer is not easy to peel off, so that the composite film is applicable to organic solvent recovery and organic gas separation in pervaporation.