33results about How to "Controllable pore size distribution" patented technology

The invention provides a core-shell structure catalyst for directional catalytic conversion of biomass synthesis gas, and also provides a preparation method and application of the core-shell structurecatalyst. The core-shell structure catalyst comprises a core layer and a shell layer, wherein the core layer is prepared from small-grain composite metal oxide, and the shell layer is prepared from porous solid acid; the small-grain composite metal oxide is a solid solution or mixture of two or more oxides of ZnO, ZrO2, Co3O4, Fe2O3, In2O3, Ga2O3, CuO, Mn2O3, NiO, Cr2O3, La2O3 and CeO2. The core-shell catalyst adopts the solid solution or mixture of the small-grain composite metal oxide having a synergistic effect on hydrogenation of CO and CO2 as the core layer, and uses the solid acid having a microporous, mesoporous or multi-stage pore structure as the shell layer. The catalyst is prepared into a core-shell structure by means of a freeze-drying method, so that not only is the problem of lower hydrogenation conversion rate of CO2 in the biomass synthesis gas at present solved, but the conversion rate of CO hydrogenation is also further improved.

This invention is related to the manufacturing technologic field of a micropore polymeric material, esecilly related to a thermoplastic polyimide micropore material and its preparation technology. Its raw materials and their percentage contents are as belows: thermoplastic polyimid(TPI): 70%-95%; pore former: 5%-30%. The micropore material is prepared by sintering humid mixed powder of polyimide and solid pore former. Its technological process is simple and it costs little. Multi-stage thermostatic sintering makes the mixed powder decompose completely and blend well with the polyimide particles. This improves material's strength and the factor of porosity. Micropore material's property can be adjusted by controlling the contend of the pore former, so it is very easy to adjust the bore diameter and the factor of porosity.

The invention discloses a method for preparing porous ceramics in the technical field of inorganic nonmetallic materials. The porous ceramics are prepared by taking the hollow ceramic ball as a pore forming agent and using a gel casting process. The method comprises the steps: firstly, presintering the hollow ceramic ball; then, preparing low-viscosity ceramic slurry and degassing; placing the presintered hollow ceramic ball into the prepared ceramic slurry; uniformly stirring the slurry and degassing again; then, adding tetramethylethylenediamine and an aqueous solution of ammonium persulfate; carrying out injection molding after uniformly stirring the mixture; next, placing a slurry injected mold into a drying oven to heat; demolding after the slurry is completely cured, and carrying out drying, glue ejection, sintering and other processes to finally prepare the novel porous ceramics. The porous ceramics prepared by the invention are favorable in mechanical property, controllable in pore diameter distribution and uniform in air hole distribution; in addition, the adverse effects of the traditional pore forming agent on a blank body during burning can be avoided, the shrinkage and deformation of various prepared porous ceramics can be effectively inhibited, and the comprehensive performances of the prepared porous ceramics can also be effectively controlled.

The invention relates to a method for preparing a pore diameter controllable porous capillary core. The method comprises the following steps of: uniformly mixing soluble salt powder which does not react with matrix powder in the matrix powder of capillary core sintering raw materials, and coldly molding the mixed powder into the capillary core with the needed shape; and performing pressureless sintering or pressure sintering on the molded raw materials under the protection of inert gases, and washing off the soluble salt to prepare the capillary core. The method has the advantages of simple preparation process, no need of a pore-forming agent and low cost, and the capillary core with high strength, controllable porosity and controllable pore size distribution is prepared.

The invention provides preparation and application of boat-fruited sterculia seed residue based sulfur-doped porous carbon. The preparation comprises the following steps: subjecting tea-made boat-fruited sterculia seed residues, which serve as a raw material, and a sulfur dopant to high-temperature carbonization in an inert atmosphere so as to obtain sulfur-doped carbon, and then, carrying out physical activating treatment, thereby obtaining the sulfur-doped porous carbon. According to the preparation and the application, the sulfur-doped porous carbon is prepared by adopting a high-temperature carbonization and physical activation combined method, the method is simple in operation, the process is easy to control, washing is not required after activation, the production cost is reduced, the carbon yield is relatively high, and the method is environmentally friendly; and the prepared sulfur-doped porous carbon is of a nanosheet structure, is controllable in specific surface area and pore size distribution, high in electric conductivity and adjustable in sulfur content and is particularly suitable for being applied to the fields of heavy-metal wastewater treatment, printing and dyeing wastewater adsorption, lithium-sulfur batteries, lithium-ion batteries, sodium-ion batteries, supercapacitors, catalyst loading and the like.

The invention discloses a method for preparing mesoporous carbon with controllable aperture distribution. The method comprises the following steps of: dispersing nano particles into a carbon precursor solution, and performing ball milling and mixing, wherein the mass ratio of the nano particles to the carbon precursor is (0.1-10): 1; controlling the consumption of the solution to keep the mixture pasty; removing the solvent, and then performing carbonization for 0.1 to 3 hours at the temperature of between 500 and 1,200 DEG C in an inert atmosphere; cleaning with acid or alkali liquor to remove a template agent; and drying the sample, and thus obtaining the mesoporous carbon with controllable aperture distribution. The carbon precursor solution comprises an ethanol solution of thermosetting phenol resin, a methylbenzene solution of asphalt, a dimethyl sulfoxide solution of polyacrylonitrile and an aqueous solution of sucrose; the mass ratio of the solution to the carbon precursor is 1:1-10:1; and the ball milling speed is 200 to 500 revolutions per minute, and the ball milling time is 0.5 to 5 hours. The preparation method is simple; the cost of the product is low; and the mesoporous carbon of which the aperture distribution is centralized in nano particle diameter, can be prepared by using a small amount of solvent.

The invention discloses a preparation method for a ZnO/perfluoropolymer nanofiber photocatalytic membrane. The method comprises the steps that A, a carrier solution and a perfluoropolymer aqueous dispersion emulsion are mixed to be uniform, zinc salt or nanometer zinc oxide is added, the mixture is defoamed after being mixed to be uniform, and a spinning solution is obtained; B, the spinning solution obtained in the step A is injected in an electrostatic spinning device, and a precursor nanofiber membrane is prepared after electrostatic spinning and vacuum drying; C, the precursor nanofiber membrane is sintered and then cooled to room temperature, and the ZnO/perfluoropolymer nanofiber photocatalytic membrane is obtained. The method is simple in process and high in controllability and reusability, and the prepared ZnO/perfluoropolymer nanofiber photocatalytic membrane is stable in photocatalytic performance and easy to recover after being used.

The invention provides a porous polyimide ink, a preparation method thereof, and a method for preparing porous polyimide through direct writing 3D printing, and relates to the fields of 3D printing technologies and porous polymer material preparation. The porous polyimide ink comprises the following components: polyamic acid, an organic solvent and a pore-forming agent. The prepared porous polyimide ink is applied to direct writing 3D printing, an obtained printed product is excellent in formability and good in size stability, and porous polyimide obtained through thermal imidization and after-treatment is uniform in pore diameter, uniform in pore distribution and communicated in pore passage. The method for preparing the porous polyimide is combined with a 3D printing technology, the problems that pores of the porous polyimide prepared through a traditional sintering method are difficult to control, complex porous components are difficult to form and the like are solved, and the method is suitable for 3D printing and forming of porous oil-containing parts that work under extreme working conditions and special conditions.

The invention provides a method for preparing porous nickel-based amorphous alloy material. The method combines a chemical reduction method with an in-situ precipitation pore-forming agent generation method. The prepared alloy material is in porous structure, has the specific surface area of 300-700 m<2>/g and the pore volume of 0.5-1.5 cm<3>/g, and the prepared amorphous alloy consists of Ni and B or Ni, B and element M; and the element M is one or multiple elements of Cu, Mo, P and Co. The method comprises the following steps: (1) solution is prepared; (2) alloy and pore-forming agent precipitation are produced through in-situ generation; and (3) prickling pore-forming is carried out, and the porous nickel-based amorphous alloy material is finally obtained. The amorphous alloy material prepared by the method has the characteristics that the aperture ratio is controllable, the pore structure and pore distribution are uniform, and the specific surface area is large. According to the amorphous alloy material prepared by the method, the specific surface area can reach more than 650 m<2>/g, the pore volume can be more than 1 cm<3>/g, the pore diameter distribution is uniform (3-4 nm), and the pore diameter is controllable.

The invention relates to a method for preparing a catalyst, the catalyst prepared by using the method, and a method for preparing glycerol monomethyl ether by using the catalyst. The method for preparing the catalyst comprises the following steps: (1) separately preparing an ethanol solution of tetraalkyl silicate and an aqueous solution of Cs salt; (2) mixing the two solutions, stirring and adjusting the pH value of the mixed solution to be alkaline, and aging; (3) spray-drying the aged material to obtain silica gel powder; (4) thoroughly mixing silica sol with the silica gel powder, extruding and molding, drying and calcining to obtain a silicon oxide carrier; (5) impregnating the silicon oxide carrier with the ethanol solution of the tetraalkyl silicate, and then treating with low pressure steam to obtain a catalyst carrier; (6) impregnating the catalyst carrier with an aqueous solution of phosphotungstic acid, drying and calcining to obtain the supported catalyst. The catalyst is good in temperature resistance, can effectively improve glycerol conversion rate and glycerol monomethyl ether selectivity, can continuously react, and is convenient to operate and high in stability.

The invention relates to a preparation method of a magnetic mesoporous zirconium dioxide compound microsphere. The preparation method comprises the steps of (1) preparing polyelectrolyte modified magnetic powder; (2) ultrasonically dispersing the polyelectrolyte modified magnetic powder and zircon salt into absolute ethyl alcohol, carrying out ultrasonic treatment to obtain a polyelectrolyte modified magnetic powder suspension liquid, then, adding a deionized water solution of ethanol and ammonium hydroxide, reacting, and then, separating by using a magnet to obtain a magnetic zirconium oxide compound microsphere with a core-shell structure; (3) ultrasonically dispersing the magnetic zirconium oxide compound microsphere into the deionized water solution of ethanol and ammonium hydroxide, carrying out hydrothermal reaction after ultrasonic treatment to obtain a product, separating the product by using the magnet, washing, and carrying out vacuum freeze drying to obtain the magnetic mesoporous zirconium dioxide compound microsphere. The preparation method provided by the invention is simple in operation, controllable in process and good in repeatability; the prepared magnetic mesoporous zirconium dioxide compound microsphere is uniform in size and pore diameter distribution, large in specific surface area, stable in physicochemical property, not easy to agglomerate and good in dispersibility, and can be applied to the fields such as environment control, proteomics and the like.

The invention belongs to the technical field of nanometer materials, and particularly relates to a preparation method of a carbon nanosheet, a positive electrode material and a preparation method of the positive electrode material. The preparation method of the carbon nanosheet comprises the following steps of providing an aluminum source and 4, 4 '-biphenyldicarboxylic acid; dissolving the aluminum source and 4, 4 '-biphenyldicarboxylic acid in an organic solvent for heating treatment, and then performing solid-liquid separation to obtain a self-assembled aluminum-based metal organic framework; and sequentially carrying out carbonization treatment and acid treatment on the aluminum-based metal organic framework, and then drying to obtain the carbon nanosheet. The preparation method is simple in process and low in cost, the finally obtained carbon nanosheet has a scaly surface structure, a hierarchical porous structure and an ultra-large specific surface area, the extra carbonaceous activation and template removal processes are not needed, and the carbon nanosheet can be compounded with selenium to serve as the positive electrode material of a lithium-selenium ion battery and has avery good application prospect.

The invention provides an in-situ synthesis method for regulating and controlling surface and interface pores and properties of a carbon membrane, which comprises four steps of carbon membrane pretreatment, introduction of a pre-preparation, in-situ synthesis and post-treatment: carbon membrane pretreatment: drying the carbon membrane to constant weight at a constant temperature, and then degassing the carbon membrane to obtain a carbon membrane suspension; preparing a pre-preparation: selecting one or more of dopamine, polyvinyl alcohol, ferric trichloride, tannic acid, hydrochloric acid, water, tromethamine, glutaraldehyde, sodium hydroxide and ferric chloride hexahydrate as the pre-preparation, preparing the pre-preparation into a solution, and performing one of a complete impregnation method, a surface impregnation method and a vacuum-assisted impregnation method to prepare the pre-preparation; the pre-preparation is introduced into the surface or pores of the pre-treated carbon membrane, so that the problems of poor pore structure and surface properties of the carbon membrane and poor separation performance of the carbon membrane on oily wastewater purification treatment when the existing carbon membrane is used for separating an oil-water mixture can be solved.

The invention discloses a process for extracting and purifying high-quality tea polyphenol by using spherical polyamide resin. The process comprises the following steps: extracting and filtering tea leaves, loading the filtered tea extract solution into a chromatographic column filled with spherical polyamide chromatographic resin for chromatography, eluting caffeine and a pigment by using a citric acid aqueous solution as an eluent, then eluting tea polyphenol by using ultrapure water and finally eluting tea polyphenol by using an ethanol aqueous solution as a mobile phase, and finally, concentrating and crystallizing the collected tea polyphenol eluent to obtain a colorless and transparent high-quality tea polyphenol crystal finished product. According to the process for extracting and purifying high-quality tea polyphenol by using spherical polyamide resin, the extraction method is simple, eco-friendly, free of pollution and low in production cost, the requirements that the purity of the tea polyphenol is larger than 99% and the extraction rate is larger than 90% can be met only through one-step chromatographic purification, the prepared tea polyphenol is high in yield, high inextraction rate and high in quality, the requirements of more fields can be met, and therefore wider market requirements are met.