396results about How to "High separation selectivity" patented technology

Membranes including anodic aluminum oxide structures that are adapted for separation, purification, filtration, analysis, reaction and sensing. The membranes can include a porous anodic aluminum oxide (AAO) structure having pore channels extending through the AAO structure. The membrane may also include an active layer, such as one including an active layer material and/or active layer pore channels. The active layer is intimately integrated within the AAO structure, thus enabling great robustness, reliability, resistance to mechanical stress and thermal cycling, and high selectivity. Methods for the fabrication of anodic aluminum oxide structures and membranes are also provided.

The present invention provides modified molecular sieve membranes with improved CO₂/CH₄ separation selectivity and methods for making such membranes. The molecular sieve membranes are modified by adsorption of a modifying agent, such as ammonia, within and/or on the membrane.

The invention discloses a preparation method of a composite polytetrafluoroethylene nano-filtration membrane. After a hydrophobic polytetrafluoroethylene micro-pore membrane is activated, the composite polytetrafluoroethylene nano-filtration membrane is obtained by virtue of water-phase soaking and oil-phase soaking. The polytetrafluoroethylene micro-pore membrane has the characteristics that the strength is high and an additional supporting layer is not needed, and thus the membrane preparation process is relatively simple. Furthermore, by virtue of a unique node-fibril micropore structure of the polytetrafluoroethylene micro-pore membrane, the bonding strength between a base membrane and a nano-filtration modified layer is greatly improved, so that the performance of the composite nano-filtration membrane is improved. The prepared composite polytetrafluoroethylene nano-filtration membrane can be used for treating wastewater in severe environments of strong acid, strong alkali, high temperature and the like, and application occasions of an existing nano-filtration membrane are expanded.

The invention discloses a method for synthesizing a molecular sieve membrane by a dip coating-rubbing crystal-coating method. The method comprises the following steps: (1) introducing a layer of molecular sieve crystal seeds onto a carrier by using a dip coating method, and rubbing the carrier coated with the crystal seeds on soft cloth to obtain a crystal seed coated carrier; (2) preparing molecular sieve membrane reaction solution; and (3) synthesizing the molecular sieve membrane by adopting a hydrothermal synthesis method, namely placing the crystal seed coated carrier into synthetic solution, taking out a membrane tube after the molecular sieve membrane is synthesized, and washing and drying the molecular sieve membrane, wherein in the (1), the dipping and drawing speed of a drawing machine is 0.1 to 5 centimeters per second, the dip coating time is 1 to 50 seconds, the concentration of dip coating solution is 5 to 50 grams per liter, and the size of the crystals is 0.20 to 10 meters; in the (2), the motor ratio of components Na2O, Al2O3, SiO2 to H2O is 1-20: 1: 1-200: 50-5,000; and in (3) the crystallization temperature is between 60 and 200 DEG C, and the crystallization time is 1 to 100 hours. The synthesized molecular sieve membrane has good separating property, and the method is simple and has good repeatability.

The invention discloses a preparation method of a hydrophobic nano mesoporous molecular sieve filling PDMC composite film, comprising the following steps: using a casting solution containing polydimethylsiloxane (PDMS), hydrophobic mesoporous molecular sieve, cross-linking agent, catalyst, and solvent to wipe film on the upper layer of a porous ultrafiltration membrane supported by polyester non-woven, and heating until crosslinking completely to obtain the composite film. The obtained mesoporous molecular sieve modified by surface silane coupling agent is combined with the PDMS substrate tightly, and is dispersed uniformly in the PDMS substrate. The preparation method has the advantages of simple process and cheap selected materials. The composite film has strong swelling resistance in dimethyl carbonate(DMC)/methanol azeotrope, and excellent DMC permselective property. When the filling weight ratio of the mesoporous molecular sieve is 30 %, the separation factor alfa is 4.07, the penetration flux J is 1.13 kg/m<2>h([DMC]=30 wt%, 40 DEG C).

Theinvention provides a scandium element extraction method. The scandium element extraction method comprises the following steps of: (A) mixing alkoxy phenoxy carboxylic acid, tributyl phosphate and a diluting agent to obtain an organic phase; and (B) extracting a scandium-containing mischmetal solution by using the organic phase to obtain a scandium ion-containing solution. The scandium element extraction method has the beneficial effects that the separation selectivity between the scandium element and other rare earth elements can be effectively improved by adopting the alkoxy phenoxy carboxylic acid as the extraction agent on the basis of ensuring the purity of a scandium product and relatively high yield; the concentration of the organic phase is effectively prevented from decreasing after extraction by adopting the tributyl phosphate as an additive, so that the organic phase can be recycled; meanwhile, an emulsion phenomenon in an extraction process can be avoided; and experimental results show that the separation coefficients of the scandium element and a lanthanide element are 526 due to adoption of the scandium element extraction method.

The present invention discloses the solvent impregnated resin which uses amide compound as the extraction agent. The extraction agent is embedded in the polymer. The prevent invention is characterized in that the polymer is the styrene - divinylbenzene copolymer resin, and the extraction agent is the amide compound with the content of 20 percent to 60 percent. The solvent impregnated resin is ivory ball particle in appearance, with a particle diameter of 60 to 200 items a heap density of 0.53 to 0.94 gram per milliliter, and a specific surface area of 128 to 260 millimeters ² / gram. The present invention also discloses the preparation method for the solvent impregnated resin. The solvent impregnated resin provided by the present invention has the advantages of low cost, less wastage of extraction agent, high column load, good mass transfer performance, easiness to be regenerated, long service life, ease use, good repeatability, and high reproducibility and so on. The solvent impregnated resin is of the characteristics of both particle and liquid in terms of extraction and cleaning. The present invention can be widely used in the separation and analysis of ⁹⁰Sr in the plant and the animal samples, in the removal and callback of ⁹⁰Sr during the treatment of nuclear fuel high-level radioactive liquid waste, as well as in the separation, purifying and callback of radioactive medical isotopes ⁹⁰Sr.

The invention discloses an MOFs (metal-organic frameworks)-cross-linked polyethylene glycol diacrylate mixed substrate membrane, a preparation and an application. PEGDA (polyethylene glycol diacrylate) is selected as substrate membrane materials, MOFs are selected as fillers, and the MOFs-cross-linked polyethylene glycol diacrylate mixed substrate membrane is prepared by ultraviolet crosslinking and curing under induction of photo-initiators. The mixed substrate membrane has remarkable performances (PCO2>160Barrer, alpha CO2/N2>70, alpha CO2/CH4>40) for separating mixed gas of CO2/N2 and CO2/CH4. Compared with a pure cross-linked polyethylene glycol diacrylate membrane, the MOFs-cross-linked polyethylene glycol diacrylate mixed substrate membrane has higher CO2 gas permeability and separation selectivity, and can be applied to purification of flue gas and natural gas.

A process for synthesizing A-type molecular sieve membrane by the vacuumizing and coating crystals method includes such steps as introducing a layer of uniform crystal seeds to the surface of base membrane by vacuumizing or compressing method, and synthesizing A-type molecular sieve membrane by hydrothermal synthesis and microwave synthesis, where the used solution contains Na2O, Al2O3, SiO2 and H2O. The resulting molecular sieve membrane features high separation performance and high repeatability.

The invention discloses a preparation method of an AlPO-18 molecular sieve membrane. The preparation method comprises following steps: (1) mixing and dissolving aluminum source, tetraethylammonium hydroxide, and phosphoric acid in water, then carrying out hydro-thermal synthesis reactions to obtain AlPO-18 molecular sieve crystal seed; (2) coating the AlPO-18 molecular sieve crystal seed on the inner surface of a porous ceramic tube carrier; (3) mixing and dissolving aluminum source, tetraethylammonium hydroxide, and phosphoric acid in water to obtain molecular sieve membrane synthesis mother liquid, putting the ceramic tube, which has been coated with the AlPO-18 molecular sieve crystal seed, in a reactor, adding the molecular sieve membrane synthesis mother liquid, and then carrying out a hydrothermal crystallization treatment so as to obtain an AlPO-18 molecular sieve membrane after aging; (4) burning the membrane tube to remove the template agent so as to obtain an activated AlPO-18 molecular sieve membrane. The AlPO-18 molecular sieve membrane synthesized by the preparation method is capable of being applied to separations of CO2/CH4 and CO2/H2, and has a high selectivity and a high throughput of separations of CO2/CH4 and CO2/H2.

The invention discloses a method for absorbing and separating light hydrocarbons from dry gas or industrial tail gas by utilizing an ionic liquid. The ionic liquid or a mixed solvent of the ionic liquid and a molecular solvent is taken as an absorbent to be in contact with the dry gas or the industrial tail gas, an absorption liquid containing the light hydrocarbons is obtained by absorption and the light hydrocarbons are further obtained by desorption and separation; and the light hydrocarbons are alkanes or olefins which mainly contain C2-C4. The invention provides the method for absorbing and separating the light hydrocarbons from the dry gas or the industrial tail gas by utilizing the ionic liquid. The ionic liquid or the mixed solvent of the ionic liquid and the molecular solvent is taken as the absorbent, an absorption-desorption method is adopted for recovery and separation of the light hydrocarbons, and the absorbent has very high solubility of the light hydrocarbons and separation selectivity, so that efficient separation and recovery of the light hydrocarbons can be realized and the highest comprehensive recovery rate can achieve 98.5%.

The invention discloses a method for synthesizing a molecular sieve membrane, which adopts a mode of crystal seed coating by a crystal seed slurry coating method for the synthesis of the molecular sieve membrane. A sol with a composition similar to that of a synthetic fluid for synthesizing the molecular sieve membrane is prepared, and the sol is mixed with molecular sieve crystals and water according to a certain proportion to prepare a crystal seed slurry; a supporting body is soaked with water, and after the surface of the supporting body is dried in the air, the crystal seed slurry is coated on the surface; when the surface is almost dry, the coating is strickled and dried to obtain a supporting body with a crystal seed layer; finally the molecular sieve membrane is synthesized by a hydrothermal synthesis method. The crystal seed layer prepared by the invention can eliminate possible defects on the supporting body surface, is distributed uniformly, and is not easy to be erased from the supporting body surface, so the synthesized molecular sieve membrane has a continuous and dense surface, excellent separation performance, good repeatability, and is applicable to large-scale production.

The invention discloses a method for synthesizing a NaA-type molecular sieve membrane on an inner wall of a support body. The method adopts a way of adding an adhesive to coat seed crystal to synthesize the molecular sieve membrane. Clear liquid, composition of which is similar to that of synthetic liquid for synthesizing the molecular sieve membrane, is prepared to serve as the adhesive, and then the clear liquid is mixed with molecular sieve crystal suspension in certain proportion to prepare seed crystal liquid; the support body is immersed into the seed crystal liquid; the support body is dried after being dipped so as to obtain the support body with the seed crystal; and finally, the molecular sieve membrane is synthesized by a dynamic hydrothermal synthesis method. According to the invention, prepared seed crystal layers are distributed uniformly, the surface of the synthesized molecular sieve membrane is continuous and dense, and the synthesized molecular sieve membrane has an excellent separating property, is good in repeatability and is suitable for large-scale production.

The invention relates to a preparation method of a pervaporation film with the preferential penetration of dimethyl carbonate. Film casting liquid containing vinyl polydimethylsiloxane (Vi-PDMS), hydrogen-containing polydimethylsiloxane (H-PDMS), hydrophobic nano SiO2, a catalyst and a solvent is adopted, a film is coated on an upper layer of a porous ultrafiltration film supported by a polyester non-woven fabric, is aired at room temperature and is also heated, and the cross linkage of the film is finished. An additive type polydimethylsiloxane compound film filled with the hydrophobic nano SiO2, which is obtained by the preparation method of the pervaporation film with the preferential penetration of the dimethyl carbonate, has a simple film preparation process, adopts the materials with low price, strong swelling resistance in dimethyl carbonate/methanol azeotropic liquid, and excellent performance of preferential penetration of the dimethyl carbonate. When the filling mass proportion of the hydrophobic nano SiO2 is 15 percent, the separation factor alpha of the pervaporation film is equal to 3.97, and the penetration flux J is equal to 0.707kg/m2h ([DMC]=30wt%, 40 DEG C).

The invention discloses a method for adsorbing and separating a sulfur-containing acid gas. The method comprises the following step: by taking an anion-containing metal-organic frame material as an adsorbent, selectively adsorbing the sulfur-containing acid gas in a gas mixture so as to obtain a purified gas, wherein the sulfur-containing acid gas comprises one or more of sulfur dioxide, sulfur trioxide and hydrogen sulfide. The anion-containing metal-organic frame material used in the method has a great number of regularly arranged inorganic anion functional groups with negative electricity, the size of the aperture of an MOF material can be adjusted in a controllable manner by adjusting the size of organic ligand, or a three-dimensional channel spatial structure can be adjusted through an interpenetration structure. The inorganic anions with negative electricity can form an electrostatic environment in a limited space of the MOF material, sulfur-containing acid gas molecules can be selectively adsorbed by virtue of an electrostatic effect of the electrostatic environment and lacked electron atoms of the acid gas, and thus high-capacity high-selectivity separation of the sulfur-containing acid gas can be achieved.

The invention discloses a composite film material based on a metal-organic framework nano-sheet and graphene oxide, and an application thereof in gas separation, and belongs to the technical fields of film materials and separation thereof. A metal oxide nano-sheet is prepared at room temperature, the metal oxide nano-sheet and a graphene oxide dispersion are paved layer by layer to form a composite film material, wherein the graphene oxide is used as a main of a film, and is doped with the metal oxide nano-sheet; and the composite film material reacts with an organic ligand to form the metal-organic framework nano-sheet doped graphene oxide composite film material. The above strategy successfully keeps an ultrathin thickness, and introduces the metal-organic framework material having uniform tunnels into the film material, so the separation selectivity of the finally obtained composite film material is 6 times higher than that of a simple graphene oxide film, and is obviously better than a film material obtained through a direct method. A result of comparison of film materials having different layers shows that the selectivity of the film obviously increases with the increase of the cycle number, the selectivity at four cycles is an optimum value, and the selectivity at five cycles decreases.

The invention relates to a preparation method of a novel polyether copolyamide gel membrane, belonging to the field of membrane separation technologies. The preparation method of the gel membrane comprises the following steps of mixing and stirring polyether copolyamide, surfactant and solvent at a certain temperature so as to obtain casting film liquor, coating the casting film liquor on a teflon plate, standing in air for a while, then drying in a vacuum drying oven for several hours, and obtaining the polyether copolyamide gel membrane. The polyether copolyamide gel membrane prepared by the method not only has excellent tensile strength and elongation at break, but also has high permeation flux and separation factor, and is especially suitable for separation of carbon dioxide and hydrogen and recycling of organic steam such as benzene and methane.

This invention relates to methods and compositions for the separation of biomolecules using capillary electrophoresis with high conductivity sieving matrices. These methods and compositions are particularly useful to increase readlength and migrational speed.

The invention discloses a molecular sieve composite membrane which is a multichannel molecular sieve composite membrane formed by molecular sieve polycrystal membranes, which are the same kind as the molecular sieve particles constituting the support body, on the internal surface of a porous multichannel composite support body formed by 40-90 wt% of molecular sieve particles (the particle sizes are 0.1-5 m) and 10-60 wt% of organic macromolecules or organic macromolecule mixture. The preparation method comprises the following steps: (1) adding sodium aluminate to distilled water, sufficiently stirring to form an aluminum solution, dissolving sodium hydroxide in the distilled water, defecating, adding a silicon source, heating and stirring to form a silicon solution, adding the aluminum solution into the silicon solution, and stirring to prepare reaction liquor for synthesizing the molecular sieve membrane; (2) and pouring the reaction liquor into a high pressure reactor, directly and perpendicularly inserting the organic macromolecular/molecular sieve composite support body into the reaction liquor to carry out the hydrothermal synthesis, cooling after crystallizing, washing with distilled water to be neutral, and drying to obtain the molecular sieve composite membrane. The invention has the advantages of simple operation, high repetitiveness of membrane formation and favorable performance, and is suitable for industrial magnification.

The invention provides a bacterial cellulose pervaporation membrane, which is characterized in that the preparation method is as follows: Acetobacter xylinum DT4.2 strain of the active wood fermentation is put into the seed culture fluid and shaking cultured at constant temperature of 25 to 32 DEG C for 8 to 24 hours; the seed solution is put into the fermentation culture solution to be evenly shaken; and then the fermentation culture solution is moved to the container for culturing for 7 to 15 days at the constant temperature of 25 to 32 DEG C; pellicle membrane formed on the surface of the fermentation solution is taken out and then is processed by the alkali liquor with the quality concentration of 1 to 20 percent; the residual alkali liquor in the membrane is washed to neutrality by the deionized water to prepare into the membrane after drying. The invention also discloses the application of the membrane. The preparation method of the membrane has the advantages of simple preparation, good mechanical and chemical property, excellent heat stability, strong hydrophilicity, high separation choice to the water in the organic water solution at lower temperature, long service life; moreover, the membrane material itself can be biodegradation which is a environmental friendly material.