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374results about How to "Uniform particle size" patented technology

Hollow core-shell nanometer mesoporous medicament carrying system with magnetism and luminescent performance, preparation method and application thereof

The invention discloses a hollow core-shell nanometer mesoporous medicament carrying system with magnetism and luminescent performance. In the medicament carrying system, a magnetic Fe3O4 hollow capsule is used as an inner core, mesoporous SiO2 is used as a shell layer, and an organic luminescent material and a biocompatible polymer are modified on the outer surface of the shell layer. A preparation method of the medicament carrying system comprises the following steps of: firstly, preparing monodisperse fusiform beta-FeOOH nanoparticles by a hydro-thermal method, coating mesoporous silicon dioxide on the surfaces of the nanoparticles, removing a pore-forming agent through thermal treatment, and simultaneously, converting the inner core into alpha-Fe2O3 from the beta-FeOOH, so that a cavity is generated in the inner core so as to form a hollow nanometer capsule structure; secondly, converting the inner core into the magnetic Fe3O4 hollow capsule through reduction treatment; and finally, modifying the organic luminescent material and the biocompatible polymer on the surface of the magnetic mesoporous nanometer capsule. The nanometer composite capsule of the invention has the advantages of core-shell structure and cavity structure, uniform particle size, high biocompatibility and excellent magnetism.
Owner:中国科学院上海硅酸盐研究所苏州研究院

Nano-zinc oxide/acrylic ester grafting composite emulsion and preparation thereof

InactiveCN101372527AUniform particle sizeImprove coating efficiency and grafting rateNano zinc oxideNanometre
The invention relates to the manufacturing field of nano composite emulsion materials, in particular to graft nano zinc oxide/polyacrylate composite emulsion and a manufacturing method thereof. Firstly an initiator azobisisovaleric acid is anchored on the surface of nano zinc oxide particles, two portions of hexadecane are added to 100 portions of mixed monomers, and 5 portions of nano ZnO particles anchoring the azo initiator are added and ultrasonically oscillated for 20 minutes to form an oil phase pre-dispersion solution. The pre-dispersion solution is added to an emulsifier aqueous solution and dispersed by a high-shear dispersion homogenizer at high speed for 30 minutes to form a mini-emulsion. The mini-emulsion is transferred to a reactor, heated to the temperature of 75 DEG C, with polyreaction initiated for 3 hours, and then heated to the temperature of 85 DEG C, polymerized for 2 hours, cooled to room temperature and discharged. The invention solves the problems of high cost and poor stability of the nano composite emulsion prepared by coupling agents, and low encapsulation efficiency and graft ratio of nano polymer composite particles. The composite emulsion has the advantages of simple preparation process, low cost, even particle size, good performance, high encapsulation efficiency and graft ratio of the nano-particles, forms nano monodisperse state in the polymer, and is suitable for the fields of coating materials, leather finishing materials, adhesives and functional plastics.
Owner:HEBEI UNIVERSITY OF SCIENCE AND TECHNOLOGY

Method and device for preparing superfine spherical metal powder for 3D printing

The invention discloses a device for preparing superfine spherical metal powder for 3D printing. The device comprises a shell, a crucible disposed in the shell and a powder collecting area. The device is characterized in that the crucible is of an inner-outer-embedded ring structure, the bottom of the inner accommodating cavity of the crucible and the bottom of the outer accommodating cavity of the crucible are provided with central holes which are communicated, space allowing molten metal to flow is arranged between the bottom of the inner accommodating cavity and the bottom of the outer accommodating cavity, a pressing piece is disposed above the central hole of the inner accommodating cavity, and a transmission rod contacts with the pressing piece; the power collecting area comprises a collecting plate disposed at the bottom of the shell and a rotary disc which is disposed above the collecting plate, connected with a motor and used for atomizing metal power particles. The invention further discloses a method for preparing the superfine spherical metal powder. The method mainly combines a pulse micro-pore injection method and a centrifugal atomizing method. By the method and the device, the superfine spherical metal powder which is narrow in particle size distribution interval, high in sphericity, good in flowability and spreading property and high in production efficiency, and the superfine spherical metal powder conforms to the application requirements of 3D printing.
Owner:DALIAN UNIV OF TECH

Preparation method of CaCu3Ti4O12 ceramic

The invention discloses a preparation method of CaCu3Ti4O12 (CCTO) ceramic, and the method can be used for solving the technical problem of high dielectric loss caused by the existing preparation method of the CaCu3Ti4O12 ceramic. The technical scheme of the invention is as follows: a casting technology is adopted to prepare a CCTO ceramic wafer, then a two-step sintering technology is adopted to obtain a ceramic material with dense structure and uniform particle size; and according to the changes of the dielectric constant epsilon r and dielectric loss tan delta of the CCTO ceramic along with the testing frequency and the temperature, CCTO crystalline integrity, grain boundary, defect and other aspects can directly influence the high dielectric constant. In addition, at the room temperature and 1KHz, when the sintering temperature is 1025-1100 DEG C and heat preservation is performed for 10 hours, the epsilon r of the CCTO ceramic prepared through two-step sintering is 104, which is more or less the same with the value reported in literatures; and the dielectric loss is reduced from 0.3-0.6 reported in the background art to 0.03, which shows that the concentration of oxygen vacancies can be reduced by adopting the two-step sintering method. Therefore, the high-temperature low-frequency dissipation of the ceramic can be significantly reduced; and the lattice distortions can be reduced along with the increase of the heat preservation time.
Owner:NORTHWESTERN POLYTECHNICAL UNIV

GPS-based unmanned aerial vehicle variable-rate spraying control device and method

InactiveCN107264804AUniform particle sizeStable spray patternAircraft componentsSpraying apparatusTraffic volumeUnmanned spacecraft
The invention discloses a GPS-based unmanned aerial vehicle variable-rate spraying control device and method. The device comprises a flight control subsystem, a sensing acquisition subsystem, a flow control subsystem and a power supply module. The sensing acquisition subsystem is connected with the flight control subsystem and the flow control subsystem separately. The power supply module supplies power for the flight control subsystem, the sensing acquisition subsystem and the flow control subsystem. The method is implemented in a way that the flow values corresponding to flight speeds are taken as the given values through an integral separation PID control strategy, then a single chip microcomputer outputs corresponding PWM signals to change the rotation speeds of a diaphragm pump, and thus the flows are changed; and the PID control strategy refers to that the flows of nozzles are detected by flow sensors, the process variables and the set values are constantly compared, and the flow of the pump is constantly corrected and controlled, so as to improve the control precision. The PWM technology is adopted to adjust the diaphragm pump, to realize the control that the flows change along with the speeds, and an intelligent variable-rate spraying control system high in efficiency, good in stability and low in cost is formed.
Owner:SOUTH CHINA AGRI UNIV

Halogen-free flame-retardant temperature controlled microcapsules and preparation method thereof

InactiveCN104650929AUniform particle sizeGood electrical conductivity and thermal stabilityHeat-exchange elementsMicroballoon preparationHalogenEmulsion
The invention discloses halogen-free flame-retardant temperature controlled microcapsules and a preparation method thereof. Each halogen-free flame-retardant temperature controlled microcapsule consists of a core material and a wall material, wherein the core material refers to liquid paraffin, the wall material refers to inorganic material silica, and the mass ratio of the wall material silica to the core material liquid paraffin is (1-3):1. The preparation method comprises the following steps: mixing, stirring and dissolving liquid paraffin, an emulsifier and distilled water, thereby obtaining emulsion; mixing ethyl orthosilicate, absolute ethyl alcohol and distilled water, regulating the pH value to 3-4, thereby obtaining silica-containing sol; adding the emulsion into the silica-containing sol, continuously stirring at a constant temperature for 2-3 hours, regulating the pH value to 5-6, aging at room temperature for 24 hours, stirring the obtained gel, performing suction filtration, washing, drying, thereby obtaining the halogen-free flame-retardant temperature controlled microcapsules. The halogen-free flame-retardant temperature controlled microcapsules have natural flame-retardant characteristic, and the formed microcapsules are uniform in granularity and have high conductivity and thermal stability.
Owner:SHANGHAI APPLIED TECHNOLOGIES COLLEGE

Preparation method for petal-shaped molybdenum disulfide hollow mesoporous carbon sphere by in-situ growth

The invention relates to a preparation method for a petal-shaped molybdenum disulfide hollow mesoporous carbon sphere by in-situ growth, and belongs to the technical field of nanometer material production. The preparation method comprises the steps of mixing ethanol, deionized water, ammonia water, tetraethyl orthosilicate, resorcinol and formaldehyde for reaction; drying a solid phase and performing calcination in argon; etching the solid phase with a sodium hydroxide solution to obtain the solid phase, and drying the solid phase to obtain the hollow mesoporous carbon nanometer sphere; mixingsodium molybdate dihydrate, thiourea and the hollow mesoporous carbon nanometer sphere for hydrothermal reaction, performing centrifugal washing after hydrothermal reaction, drying the solid phase, and performing high-temperature calcination under protection of argon atmosphere to obtain the petal-shaped molybdenum disulfide hollow mesoporous carbon sphere by in-situ growth. The preparation method has the advantages that the raw material is low in cost, the process is environmental-friendly, high yield is achieved, and the prepared petal-shaped molybdenum disulfide hollow mesoporous carbon sphere by in-situ growth can be used as a lithium ion battery electrode material, a photocatalytic material or an electrocatalytic material.
Owner:YANGZHOU UNIV

Method for preparing lithium-rich manganese-based layered lithium battery cathode material based on efficient solid-phase chemical complexation reaction

The invention discloses a method for preparing a lithium-rich manganese-based layered lithium battery cathode material based on an efficient solid-phase chemical complexation reaction. The method comprises the following steps: firstly preparing a lithium source, a nickel source and a manganese source which are used as raw materials and preparing a solid ligand complexing agent; dry-blending the prepared raw materials and the solid ligand complexing agent according to a certain molar ratio based on stoichiometric ratio of metallic elements in a molecular formula of the target product lithium-rich manganese-based layered lithium battery cathode material which is to be prepared, and fully grinding; drying mixed materials obtained at low temperature to obtain a solid-phase complexing agent precursor; and sintering the solid-phase complexing agent precursor in the air or in an oxygen-enriched atmosphere, so as to obtain the lithium-rich manganese-based layered lithium battery cathode material. The method provided by the invention is simple and easy to control, is green and environmentally friendly, and has advantages of low production cost, high production efficiency and excellent product performance.
Owner:CHANGSHA RES INST OF MINING & METALLURGY

Peony seed oil microcapsule and preparation method of peony seed oil microcapsule

InactiveCN105028706AGood water solubility and stabilityUniform particle sizeEdible oils/fatsEmulsionChemistry
The invention discloses a peony seed oil microcapsule and a preparation method of the peony seed oil microcapsule, and belongs to the technical field of food engineering. The peony seed oil microcapsule comprises a core material phase and a wall material phase. Through being metered by weight parts, the core material phase consists of 10 to 60 parts of peony seed oil and 0.5 to 5 parts of oil soluble emulsifiers; the wall material phase consists of 20 to 75 parts of wall materials, 5 to 50 parts of wall material connecting auxiliary agents, 20 to 150 parts of water, 1 to 8 parts of water-soluble emulsifiers and 0.5 to 5 parts of stabilizers. The pressure emulsification homogenizing is used, so that the particle diameter of an emulsion reaches the nanometer level, so that the particle size of an obtained product is uniform; the reconstitution capacity is good; the solubleness is good; the peony seed oil microcapsule can be dissolved in cold water; no precipitate and no floating object exist in a solution; no floating oil exists after the still standing for 48 hours; the solution can be compounded with other emulsions such as milk; the application range of the peony seed oil is expanded. The peony seed oil microcapsule and the preparation method have the advantages that the process is simple; the production cost is low; the product stability is greatly improved; and the nutrition activity of the peony seed oil is maintained.
Owner:刘进
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