155results about How to "Particle size is easy to control" patented technology

The invention discloses a method for preparing a biocompatible aqueous quantum dot. The method comprises the following steps: a high-quality quantum dot and a nucleocapsid structure thereof are prepared; a surface modification technology is combined; the nucleocapsid structure is utilized to improve the stability of the quantum dot; through mutual action of intermolecular force, an organic molecular chain on the surface of the quantum dot is changed; an organic molecule of a long chain on the surface of an oil-phase quantum dot is changed into a small molecule which contains sulfhydryl and carboxyl or amidocyanogen and has biocompatibility and is water-soluble or a derivative of a large biological molecule; and finally, the biocompatible aqueous quantum dot which can be directly dissolved in phosphate buffer and the like is obtained. The method has the advantages: the preparation and surface modification method of the quantum dot are simple and easy to control the quality, the dimension and the surface property of the quantum dot; the obtained aqueous quantum dot has the advantages of higher fluorescent efficiency, even distribution of particle diameter, strong stability and the like; and the aqueous quantum dot prepared by the method can be used for biological detection, medical diagnosis, energy transferring and the like.

The invention relates to polydopamine microcapsules and a preparation method thereof. The polydopamine microcapsules are prepared from dopamine serving as a raw material and calcium carbonate particles serving as templates in a mass ratio of 0.1:1-10:1. The preparation method comprises the following steps of: preparing the calcium carbonate particles serving as the templates; adsorbing the dopamine on the templates so as to form polydopamine membranes on the templates by the self-polymerization of the dopamine; reacting for a certain period of time; and removing a calcium carbonate kernel by using ethylene diamine tetraacetic acid disodium after the polydopamine membranes on the templates reaches a certain thickness. For the microcapsules prepared by the method, a preparation process is simple and is convenient to operate, an acid-base catalyst and an organic solvent are saved, the raw material is readily available, the thickness of each membrane is easy to control through the assembly of different layers, the size of each particle is controllable, stability and repeatability are high and a wide application range is achieved.

The invention discloses a method of improving the coercivity of sintering Nd-Fe-B magnetic materials. The method includes the following steps of using hydrogen to crush Nd-Fe-B alloy, powder processing, compression moulding, sintering and tempering under the protection of vacuum or protective gases. The sintering condition consists of heating to 300 to 600 DEG C, keeping the temperature for 5 to 6 hours to dehydrogenize, heating once again to 1060 to 1120 DEG C, sintering for 1 to 60 minutes under high temperature, finally decreasing the temperature to 1000 to 1050 DEG C, keeping sintering for 1 to 4 hours under the temperature and cooling. The method adopts the steps of sintering for a short period under high temperature to precipitate the liquid phase and then sintering under lower temperature. The liquid phase is rapidly precipitated under high temperature, thereby improving the sintering process of the magnetic materials, promoting the performance of sintering process, controlling the grain size through sintering under lower temperature, inhabiting grain growth and benefiting obtaining an excellent coercivity of magnetic materials.

The invention relates to a sea urchin shaped copper oxide catalyst, as well as a preparation method and application thereof, and belongs to the field of catalysts. The preparation method for the sea urchin shaped copper oxide catalyst comprises the following steps of: dissolving a copper salt and a dispersant into an organic solvent, performing solvent heat reaction in an alkali environment, and thus obtaining the sea urchin shaped copper oxide catalyst. The method for preparing the sea urchin shaped copper oxide is concise, easy and convenient to operate, efficient, low in price and environment-friendly, and realizes large-scale preparation. The sea urchin shaped copper oxide catalyst prepared by the method is controllable in shape and granular size, and can be used for synthesizing organic silicon monomers.

The invention discloses a double-shell-structure carbonyl iron powder composite wave-absorbing material and a preparation method thereof, wherein the composite wave-absorbing material is of a double shell layer core-shell structure, the core is carbonyl iron powder, the inner layer of the double-shell layer is an insulating layer, and the outer layer of the double-shell layer is a magnetic layer;the thickness of the insulating layer is 1 nm-1 [mu] m; and the thickness of the magnetic layer is 1nm-5 [mu] m; the preparation method comprises the following steps: coating the surface of the carbonyl iron powder with the insulating layer and coating the surface of a core-shell structure precursor by a chemical coprecipitation method. The surface of the carbonyl iron powder is coated with the double-shell layer by the chemical coprecipitation method. The impedance matching characteristic of the material is greatly improved, meanwhile, a large amount of nano-interface heterojunction is formedat the interfaces of the inner core and the double-shell layer, so that interface polarization is effectively induced, the scattering effect is formed for electron migration, and electromagnetic waveloss mechanisms such as multi-reflection absorption, strong ] ferromagnetic resonance and eddy current loss and the like of the material are greatly improved, so that the wave absorbing performance of the material is remarkably improved; the composite wave-absorbing material is simple in preparation method, is uniform and compact in coating and controllable in coating layer thickness and particlesize.

The invention relates to a barium titanium iron series phhotocatalyst and a preparation method thereof, and belongs to the field of phhotocatalyst. In accordance with the chemical formula Bi5FeTi3O15, the invention adds titanium salt or titanate, malysite, bismuth salt into deionized water or acidic solution to dissolve and mix evenly, adds in aqueous alkali to produce settlings, and then adds the settlings into a water heat retort; after water heat reaction, the Bi5FeTi3O15 catalyst material is obtained after centrifugation, washing and drying. The invention reduces energy consumption of synthesization, and the product has even components, controllable grain size, quite high specific surface area, and good photocatalytic performance.

The invention comprises a charging device, a drying belt driving device and a vacuum plant. The charging device includes a charger mixer, a dosage pot and a single-screw pump mounted one by one. The drying belt driving device is disposed in an enclosed vacuum chamber and has several layers of drying belts with the driving device inside. The vacuum plant includes a vacuum distributor and vacuum pipelines.

The invention discloses a preparation method of lithium titanate. The preparation method is characterized by comprising the following steps of: combining TiO2 powder which is wrapped by using a carbon source or is mixed by using a carbon material or a tabletting with a metal current collector so as to be used as a cathode; by taking graphite as an anode and taking a molten alkali halide as an electrolyte, electrolyzing for 1-5 hours in an argon atmosphere at an electrolysis temperature of 400-700 DEG C under an electrolysis voltage of 2.0-3.2V, cooling down to be the normal temperature and taking out, subsequently washing in distilled water or an organic solvent, and drying in vacuum so as to obtain LiTiO2 which is wrapped by using the carbon source or is mixed by using the carbon material; washing an electrolysis product, drying the electrolysis product in vacuum, and subsequently firing for 1-3 hours at 600-900 DEG C in air so as to obtain Li4Ti5O12. By utilizing the method, product grain size controllability is realized, and the problems of product batch stability and consistence caused by in-scale production are solved. The lithium titanate prepared by using the method can be used as an energy material to be directly applied to lithium ion secondary batteries and super-capacitors.

The invention discloses preparation methods of a spherical lithium manganate for a lithium-ion power battery and a precursor of the spherical lithium manganate. The preparation method for the precursor is carried out as the following steps: (1) preparing a manganese salt water solution; (2) preparing a precipitant water solution; (3) injecting the prepared solutions in the step (1) and the step (2) to a reaction kettle with a stirrer and a constant-temperature water bath; (4) mixing the obtained MnCO3 and a compound containing an element M based on a mol ratio of M to Mn described in the invention, sintering and obtaining the precursor. The preparation method of the spherical lithium manganate is carried out as the following steps: mixing the precursor and Li2CO3, sintering and obtaining an M-doped spherical spinel lithium manganate. Compared with the prior art, the method of the invention has the advantages that: (1) impurity content is low, discharge plateau is high, specific capacity is high, cycle performance is good, high-temperature performance is good and tap density is high; and (2) raw material price and production cost are low, powder particle size can be controlled, microscale additive disperses uniformly, particle size distribution is concentrate, and microscopic morphology is spherical or spheroidic.

The invention relates to a graphene-loaded nanometer Fe<3>O<4>/ZnO composite with an electromagnetic shielding function and a preparation method thereof. Te preparation method includes the steps that firstly, ferric chloride hexahydrate and Zn powder are mixed to be uniform after no sediment exists, an alkaline solution and a graphene oxide solution are added, and after the mixture is stirred to be uniform, suspension liquid is obtained; then, the suspension liquid is placed in a reaction kettle to be subjected to constant temperature heat treatment, centrifugal separation is conducted, and obtained paste-shaped solid is placed in a tube-shaped furnace to be subjected to thermal recovery under the mixed atmosphere of H<2>/Ar after being refrigerated and dried; finally, the graphene-loaded nanometer Fe<3>O<4>/ZnO composite is obtained. The graphene-loaded nanometer Fe<3>O<4>/ZnO composite prepared through the method is high in degree of dispersion and good in water solubility, the magnetic property and the electromagnetic shielding property are remarkably enhanced, the operation process is simple and efficient, and industrialized production and application is achieved easily.

The invention relates to a kitchen garbage disposer capable of realizing two-stage crushing. The kitchen garbage disposer comprises an end cover, an upper cavity body, a lower cavity body, a crushing cutter disc and a drill bit cutter disc, wherein the end cover is mutually connected with the upper cavity body through a screw, and the upper cavity body is mutually connected with the lower cavity body through a screw; a screen drum is installed between the end cover and the upper cavity body; the crushing cutter disc is mutually matched with a rectangular tool at the lower end of the end cover and arranged in the screen drum; the upper end of a transmission shaft is in threaded connection with the crushing cutter disc, and the lower end of the transmission shaft penetrates through a circular tray and is connected with a motor in the lower cavity body; a support disc is mutually bonded with a funnel, and fixed to the middle part of the upper cavity body through a screw; the drill bit cutter disc is fixed to a large circular table of the transmission shaft through a screw; a circular tray is in threaded connection with the lower cavity body; and a waste discharge port is formed in the lower end of the upper cavity body. The kitchen garbage disposer disclosed by the invention has the following advantages: the garbage crushing efficiency is increased due to the design of a multi-stage crushing device; and the kitchen garbage disposer is ingenious in overall structure and convenient to use.

The invention discloses a method for preparing neodymium iron boron powder by means of a hydrothermal method. The method comprises the steps of (1) dissolving neodymium nitrate, ferric nitrate, nitrate of metal M, boric acid and a surface active agent into water; (2) adjusting the PH value, heating the mixture in a reaction kettle, and preserving the temperature in the reaction kettle to obtain sediment; (3) cleaning and drying the sediment, and obtaining powder in the air by means of heat treatment; (4) uniformly mixing the powder with calcium powder, carrying out high-temperature reduction heat treatment on the powder inside a vacuum-tube-type furnace, and obtaining the neodymium iron boron powder after the powder is cleaned. According to the method for preparing the neodymium iron boron powder, the sizes of granules of the sediment obtained and prepared by means of the hydrothermal method can be controlled, dispersion of the granules is good, the size of grains of the neodymium iron boron powder obtained after reduction heat treatment is from 0.2 micrometer to 20 micrometers, and the magnetic performance is higher.

The invention discloses a process for preparing low-temperature sintering nano-silver paste. The process comprises the following steps: 1) preparing blank reverse microemulsion and making a pseudoternary phase diagram; 2) preparing the reverse microemulsion containing nano-silver particles; 3) performing centrifugal separation: performing centrifugal separation on the reverse microemulsion containing the nano-silver particles 2-4 times, separating oil phase organic matter and aqueous phase solution, and obtaining the nano-silver particles adsorbed by mixed surfactants; 4) causing the nano-silver particles adsorbed by the mixed surfactants obtained in the step 3) to be mixed with organic carriers, adjusting the viscosity, and preparing the low-temperature sintering nano-silver paste. The process has the advantages that the nano-silver particles are wrapped with the surfactants from nucleation growth to the formation of final slurry, the hard aggregation of the nano-silver particles is greatly reduced, the nano-silver particles prepared through the process are controllable in size, and the preparation process is simplified.

The invention belongs to the technical field of luminous materials and relates to a nanogold shell coated upconversion nanocrystal composite structure material and a preparation method of the material. The material solves the technical problems of large nano particle size, low fluorescence intensity, incomplete core-shell structure and poor biological tissue penetration capacity of the existing rare-earth upconversion luminescent material. The invention provides the nanogold shell coated upconversion nanocrystal composite structure material in a fluoride and oxide upconversion nano core-shellstructure. The invention further provides the preparation method of the composite structure material. Compared with the upconversion luminescent material prepared by the traditional method, the nanogold shell coated upconversion nanocrystal composite structure material is small in particle size, regular in pattern, good in dispersity, good in biocompatibility, and easy in surface biological functionalization; a gold shell is ultrathin, complete and consecutive; and selectively reinforced fluorescence emission is obtained by adjusting a position of an SPR (surface plasmon resonance) absorptionpeak. The preparation method of the material has the advantages of good controllability, low reaction temperature, low equipment requirements, simple in-situ synthesis operation technology and the like.

The invention relates to the field of a catalyst used in synthesis of dimethyl dichlorosilane, in particular to a ternary copper catalyst used in synthesis of the dimethyl dichlorosilane and a preparation method of the ternary copper catalyst. The preparation method according to the invention comprises the following steps of: (1) dissolving a copper salt into a mixed solvent of polybasic alcohol and water to obtain solution with copper ion concentration of 0.0025-0.25 g/mL; and (2) dropwise adding pH regulator aqueous solution into the solution obtained by the step (1) under a stirring condition, transferring the solution into a reaction kettle after the pH value of the solution is 6-13, reacting at 100-250 DEG C for 2-30 hours to obtain brown precipitate, and washing and drying the precipitate to obtain the ternary copper catalyst. The ternary copper catalyst prepared by the invention has the advantages of simple experimental process route, convenience in operation, entire process performed in the reaction kettle, no need of any complex experimental equipment, high reaction speed, easiness for large-scale production and capability of showing higher selectivity for the dimethyl dichlorosilane and higher conversion rate for a silicon powder raw material.

The invention discloses a method for preparing CuCrS2 nano powder and belongs to the technical field of nano materials. In the method, Cu powder (more than or equal to 99.9 mass percent), Cr(more than or equal to 99.9 mass percent) and S powder (more than or equal to 99.9 mass percent), serving as raw materials, are mixed according to a stoichiometric molar ratio of Cu to Cr to S of 1:1:2 of the final product and then put in a planetary ball mill to be milled at a certain rotation speed to form compound powder, then a certain amount of absolute ethanol is added into the compound powder for wet milling, and drying a resulting product to obtain the CuCrS2 nano powder which has a uniform particle size of 5 to 990 nano meters. The preparation method has the advantages that: the raw materials are cheap and readily available; the preparation process is simple, quick and easy in operation; and the requirements on equipment and preparation environment are low; and the particle size of the powder is uniform and controllable.

The invention discloses a catalyst for C4 fraction selective hydrogenation and removal of alkyne, and a preparation method thereof. A main metal active component precursor loaded on a carrier and assistant metal component precursors loaded on the carrier are reduced through ionizing radiation to prepared the unsaturated hydrocarbon hydrogenation catalyst provided by the present invention. The main metal active component precursor comprises Pd, wherein the Pd content is 0.01 (wt)%-2.00 (wt)% of the total weight of the carrier. The assistant metal component precursors comprise: (1) at least one selected from Cu, Co, Ag, Cr, Bi, Sn, Pb, Ga, Zn, Sb and Tl, wherein the metal content is 0.005 wt%-30.0 wt% of the total weight of the carrier; (2) optional one or a plurality of metals selected from Na, K, Mg, Ca and Ba, wherein the metal content is 0.005 wt%-5.0 wt% of the total weight of the carrier. The catalyst has advantages of high activity, high selectivity, no requirement of pre-reduction through hydrogen, direct use and the like.