50results about How to "Solve the uniform dispersion" patented technology

The invention provides a preparation method of a polylactic acid/nano cellulose composite material. The composite material comprises the following components in percentage by weight: 55 to 99.8% of polylactic acid, 0.1 to 15% of nano cellulose, and 0.1 to 30% of polyethylene glycol. The method comprises the following steps of: preparing a 5 to 15% an aqueous solution of microcrystalline cellulose, dripping concentrated sulfuric acid until the concentration of sulfuric acid reaches 40 to 60%, stirring and reacting for 1 to 2hours, carrying out centrifugation, ultrasound treatment and adjusting pH value to be neutral to obtain a nano cellulose suspension; dissolving polyethylene glycol, mixing with the nano cellulose suspension, stirring for 1 to 3hours at the temperature of 90 DEG C and carrying out vacuum drying to obtain a polyethylene glycol/nano cellulose comixture; and carrying out melt blending on the polyethylene glycol/nano cellulose comixture and polylactic acid for 5 to 8minutes at the temperature of 120 to 170 DEG C to obtain the composite material. The method is convenient and simple to operate, short in the time of the preparation process and solves the problem of uniform dispersion of nano-cellulose in the polylactic acid.

The invention provides a method for preparing mesocarbon microbeads by copolycondensation, which belongs to the technical field of deep processing of coal and is characterized by comprising the following process procedures of: mixing coal tar pitch with coal liquefaction residue pitch in proportion, further heating the mixture at 300-350 DEG C till a low velocity state is obtained, reacting at 390-450 DEG C under a pressure of 0.2-2MPa for 5-12h after stirring uniformly to generate pitch containing the mesocarbon microbeads, subsequently washing with light fraction of coal tar and an organic solvent to obtain the mesocarbon microbeads. According to the invention, the coal tar pitch and the coal liquefaction residue pitch are used as raw materials in copolycondensation reaction; the problems that a large quantity of nucleation promoter needs to be added in preparation of MCMB (mesocarbon microbeads) by using the coal liquefaction residue as the raw material, especially in industrial scale, and the addition of the large quantity of nucleation promoter results in homodisperse are solved; furthermore, no compatilizer needs to be added. The prepared MCMB is narrower in particle size distribution, the yield can reach 30% and the product has good sphericity.

The invention relates to a preparation method of a carbon-nanotube-enhanced copper-based composite material, and belongs to the technical field of composite material preparation. The method comprises:putting carbon nanotubes in an acid solution, performing ultrasonic dispersion treatment for 20-120 min, performing heating to 50-80 DEG C, maintaining the constant temperature for 5-15 h, and performing filtering, washing, and drying to obtain pre-treated carbon nanotubes; preparing a carbon nanotube and copper salt composite solution with the pre-treated carbon nanotubes; taking a pure titaniumplate as a cathode, a pure copper plate as an anode, the carbon nanotube and copper salt composite solution as a plating solution, performing electroplating at the temperature of 25-50 DEG C with thecurrent density of the cathode being 0.5-20 A/dm2; when the deposition electric quantity is 50-200 C, taking the cathode out, peeling a composite film off, and cleaning and drying the composite filmto obtain carbon-nanotube-enhanced copper-based composite film; laying the composite films layer by layer, and performing compacting molding to obtain a carbon-nanotube-enhanced copper-based compositeblock; and sintering the composite block to obtain the carbon-nanotube-enhanced copper-based composite material. In the composite material, carbon nanotubes are uniformly distributed in the compositefilm layer in a network manner.

The invention provides a preparation method for nickel-plated carbon nano tube reinforced aluminum matrix composites. The method includes the steps that 1, the outer portion of a carbon nano tube is plated with nickel, so that a nickel-coated carbon nano tube is obtained; 2, aluminum powder or aluminum alloy powder, the nickel-coated carbon nano tube and a process control agent are mixed for ball-milling, so that composite powder is obtained; 3, the composite powder is packaged in a metal cover and is rolled after temperature rises, so that a composite material blank is obtained; 4, the metal cover is stripped, burs are removed, and then the nickel-plated carbon nano tube reinforced aluminum matrix composites are obtained. The nickel-plated carbon nano tube is used for improving the interface of the aluminum matrix composites, a high-temperature interface reaction between the carbon nano tube and an aluminum matrix can be avoided, and meanwhile wettability between the carbon nano tube and the aluminum matrix can be improved. Moreover, the nickel layer on the surface of the carbon nano tube can react with the aluminum matrix to generate intermetallic compounds, the interface bonding strength between the carbon nano tube and an aluminum matrix is improved, and accordingly the mechanical properties of the composite materials are improved.

A method for preparing a transparent Raman effect film relates to preparation of optical fiber films and aims to solve the problems of complicated equipment and difficulty in controlling a production process of an existing method for preparing SERS (surface enhanced Raman scattering) base materials. The method includes the steps: firstly, preparing cellulose acetate solution with acetone, acetic acid and cellulose acetate; secondly, uniformly mixing Ag NPs suspending liquid and the cellulose acetate solution to obtain spinning liquid; thirdly, spinning the spinning liquid into a nano-fiber nonwoven felt by means of electrostatic spinning process; and fourthly, tiling the cut nano-fiber nonwoven felt in a slot of a composite film forming tool, pouring polyvinyl alcohol water solution into the slot, leading the polyvinyl alcohol water solution to be lower than the upper edge of the slot of the composite film forming tool, and maintaining pressure and drying to obtain the transparent Raman effect film. The method is mainly used for preparing the transparent Raman effect film.

The invention relates to a one-step in situ synthesis method for preparing transparent organic flaming retarding composite material. Methyl methacrylate is taken as raw material, Na-montmorillonite and magnesium hydroxide are taken as fire retardant, firstly the Na-montmorillonite is purified, magnesium hydroxide microemulsion is prefabricated, methyl methacrylate monomer is added into a four-opening flask, and initiating agent azodiisobutyronitrile absolute alcohol solution is dripped in under the conditions of protection of nitrogen, water circulation condensation, continuous heating at constant temperature and uniform stirring, thus methyl methacrylate + magnesium hydroxide + Na-montmorillonite three phase composite material, namely the organic flaming retarding nano composite material, is synthesized by one step. The material is in white unconsolidated composite particle power, the average particle size of magnesium hydroxide in base after film forming is 60nm, the Na-montmorillonite is stripped, luminousness of product is 85%, absorption rate of ultraviolet light is 40%, limited oxygen index is improved from 19% to 26%, and hardness can be improved by 10%. The method uses less devices, process flow is short, no environmental pollution is produced, and yield is high.

The invention discloses a nylon /silica composite microsphere, a preparation method and an application thereof. The composite microsphere is spherical and/or near spherical particles with the particle size of 0.5-300 [mu]m, and is formed by an aperture-containing nylon microsphere matrix and silica uniformly dispersed in the aperture-containing nylon microsphere aperture and/or surface. The content of the aperture-containing nylon microsphere is 10-99.9 wt%, and the content of the silica is 0.1-90 wt%. The composite microsphere is obtained by performing silica in-situ hydrolysation in aperture-containing nylon microsphere dispersion liquid. Addition of silica can effectively reduce the water absorption of the aperture-containing nylon microsphere, and increases the heat stability, crystallization property and mechanical intensity; the composite microsphere can be taken as consumable in a SLS selective laser sintering technology, and widens the application of the SLS technology in the fields of aviation, automobile, medical apparatus, electronic apparatus, machinery die and artwork.

The invention belongs to the field of lithium ion battery material preparation, and in particular relates to a preparation method of a carbon nanotube modified lithium-rich manganese-based positive electrode material xLi2MnO3. (1-x) LiMO2. According to the preparation method, a precursor and a carbon nanotube are modified at the same time in a pre-oxidation mode; a conductive network combination of the carbon nanotube and the positive electrode material can be formed; and the conductivity of the prepared material is improved. The preparation method comprises the steps of uniformly mixing a transition metal salt solution according to a stoichiometric ratio, dropwise adding a precipitant and a complexing agent, washing and drying to obtain a precursor, stirring, dispersing and drying the precursor and a carbon nanotube aqueous dispersion, adding into an oxidant solution for pre-oxidation, drying, mixing with a lithium source, calcining and cooling to obtain a final product. The lithium-rich manganese-based material disclosed by the invention not only has high specific capacity, but also has excellent rate capability and cycle performance. A lithium ion battery adopting the positive electrode material has huge application potential in the aspect of power batteries.

The invention provides preparation and application of a silicon nitride coated carbon nano tube, and belongs to the technical field of functional materials. A preparation method of the silicon nitridecoated carbon nano tube comprises the following steps that S1, the carbon nano tube is loaded into a whole reaction kettle in a loosening mode and the whole reaction kettle is filled with the carbonnano tube, and then vacuumizing is carried out to 0.1-100Pa; then silicon tetrachloride gas is introduced into the reaction kettle to initial pressure in the reaction kettle being in a range of 1-2atm; then ammonia gas is introduced continuously and reacts with the silicon tetrachloride gas under -20-60 DEG C, and a nitrogenous silane compound generated by the silicon tetrachloride gas and the ammonia gas is deposited on the surface of the carbon nano tube; S2, at an ammonia gas atmosphere, the carbon nano tube attached with the nitrogenous silane compound on the surface in the S1 is heated to500-600 DEG C, and heat treatment is carried out for 1-2 hours; and S3, continuous heating is carried out to 650-1200 DEG C, heat treatment is carried out for 2-8 hours, so that the nitrogenous silane compound is decomposed into amorphous silicon nitride, and the amorphous silicon nitride is uniformly deposited on the surface of the carbon nano tube. According to the preparation and application of the silicon nitride coated carbon nano tube, industrial production requirement and application of the silicon nitride coated carbon nano tube can be realized.

The invention discloses a preparation method of carbon nanotube toughened silicon carbide ceramic, and belongs to the technical field of composite ceramic materials. The preparation method of the carbon nanotube toughened silicon carbide ceramic comprises the following steps: S1, uniformly mixing silicon carbide, carbon black, silicon nitride coated carbon nanotubes, water-soluble phenolic resin and pure water to obtain uniformly dispersed slurry with the solid content of 48-52%; S2, heating the slurry obtained in the step S1, evaporating to remove water to obtain a blocky material, carrying out dry pressing on the blocky material, and carrying out one-step molding to obtain a green body; S3, covering the surface of the green body with monatomic silicon, putting the green body into a vacuum high-pressure sintering furnace, heating to 1300-1400 DEG C, keeping the temperature for a certain period of time, and converting amorphous silicon nitride on the surface of the carbon nano tubes into hexagonal silicon nitride; and heating up to 1450-1500DEG C, and keeping the temperature for a certain period of time to obtain the carbon nanotube toughened silicon carbide ceramic; the fiber structure of the carbon nanotubes can be reserved in the reaction sintering process, the toughening effect of carbon fiber is fully exerted, and the performance of the composite ceramic material is enhanced.

The invention discloses a conductive resin for a 3D printing technology, and a preparation method and application thereof, and belongs to the technical field of 3D printing materials. The conductive resin comprises, by weight, 70-95 parts of a polymerization reaction material, 20-35 parts of a conductive material and 0.5-3 parts of a photoinitiator, and the polymerization reaction material comprises hydroxyethyl acrylate, polyethylene glycol diacrylate, polyvinyl alcohol, acrylamide and modified polydimethylsiloxane. According to the polymerization reaction material disclosed by the invention, the components are mutually cooperated, and a stable three-dimensional network structure is formed through physical crosslinking and chemical crosslinking, so that the mechanical property of the resin can be effectively improved, and the problem that the conductive material dispersed in water is uniformly dispersed in the resin is solved; therefore, the conductive stability of the conductive resin is improved, and the problem that the mechanical property of conductive hydrogel with similar components becomes poor due to water loss is solved. The resin is simple in preparation method, is manufactured through a photocuring 3D printing technology, and has a huge application prospect in the fields of flexible sensing and the like.

The invention belongs to the technical field of functional polymer materials, and particularly relates to self-antibacterial lactic acid-based waterborne polyurethane as well as a preparation method and an emulsion thereof. Water-based chitosan and hinokitiol structures are introduced to a side chain of a large polyurethane long chain by self-antibacterial lactic acid-based waterborne polyurethane and are uniformly distributed, so that two substances with different antibacterial and bactericidal mechanisms mutually generate a bactericidal and antibacterial synergistic effect, the drug resistance of bacterial organisms can be effectively reduced, and meanwhile, the two substances are grafted on a polyurethane long chain in a chemical bond manner, so that the antibacterial property is lasting.

The invention discloses a colored toner prepared by adopting mini-emulsion polymerization and ball-milling compounding and a method. The method comprises the following steps: adopting a mini-emulsion polymerization method to prepare core-shell compound emulsion particles of a resin coated pigment and polyethylene wax, wherein the particle sizes of the prepared compound emulsion particles are 100 to 200 nm; then, preparing composite particles with the particle sizes of 7 to 12 microns through an electrolyte agglomeration compound method, and then compounding a charge control agent onto the micron composite particles through mechanical milling. Charge stabilization is provided for monomer droplets by using a negative (positive) ionic type polyethylene wax emulsion, and the addition of an ionic type emulsifier is avoided, so that the technology is simpler; the charge control agent is compounded to the particle surface of the colored toner through the mechanical milling method, and the charge control agent is uniform in arrangement, simple in technology and simple in operation, so that the particle charges of the finally obtained colored toner is uniformly distributed.