3362results about How to "Narrow particle size distribution" patented technology

A water soluble semiconductor nanocrystal capable of light emission is provided, including a quantum dot having a selected band gap energy, a layer overcoating the quantum dot, the overcoating layer comprised of a material having a band gap energy greater than that of the quantum dot, and an organic outer layer, the organic layer comprising a compound having a least one linking group for attachment of the compound to the overcoating layer and at least one hydrophilic group space apart from the linking group by a hydrophobic region sufficient to prevent electron charge transfer across the hydrophobic region. The particle size of the nanocrystal core is in the range of about 12.ANG. to about 150.ANG., with a deviation of less than 10% in the core. The coated nanocrystal exhibits photoluminescende having quantum yield of greater than 10% in water.

Apparatus suitable for atomizing and vaporizing at least a first liquid by colliding at least one gas with the first liquid. The apparatus includes a gas inlet through which the gas enters the apparatus and a first liquid inlet through which the first liquid enters the apparatus. A discharge end of the apparatus includes at least one first liquid discharge outlet through which at least one stream of the first liquid is discharged from the apparatus. The discharge end also includes at least one gas discharge outlet through which at least one stream of gas is discharged from the apparatus to collide with and thereby atomize the discharged stream of the first liquid. A first liquid passageway interconnects the first liquid inlet with the first liquid discharge outlet. A gas passageway interconnects the gas inlet with the at least one gas discharge outlet. In one embodiment, the gas passageway comprises at least one gas chamber in thermal contact with an initial portion of the first liquid passageway such that a heated quantity of the gas in the chamber preheats the first liquid in the initial portion of the first liquid passageway. In alternative embodiments, the gas passageway includes a pressure dampening chamber allowing gas to be continuously discharged without pulsating.

A lithium / iron disulfide electrochemical battery cell with a high discharge capacity. The cell has a lithium negative electrode, an iron disulfide positive electrode and a nonaqueous electrolyte. The iron disulfide of the positive electrode has a controlled average particle size range which allows the electrochemical cells to exhibit desired properties in both low and high rate applications. In various embodiments, the iron disulfide particles are wet milled, preferably utilizing a media mill or milled utilizing a non-mechanical mill such as a jet mill, which reduces the iron disulfide particles to a desired average particle size range for incorporation into the positive electrode.

The invention relates to spherical carriers for an olefin polymerization catalyst and a preparation method. Each spherical carrier comprises reaction products of the following components: (1) magnesium halide which is shown as the general formula MgX2, (2) alcohol compounds which are shown as the general formula ROH, and (3) ethylene oxide compounds which are shown as the general formula (I), wherein in the general formula (I), R2 and R3 are alkyls with a C1-C5 straight chain or branched chain; and hydrogen on the alkyls can be randomly substituted by a halogen atom. The spherical carriers have good particle shapes, adjustable particle sizes and narrow particle size distribution, and the preparation method is simple.

An object of the present invention is to provide nickel cobalt manganese composite hydroxide particles having a small particle diameter and a uniform particle size distribution, and a method for producing the same.[Solution]A method for producing a nickel cobalt manganese composite hydroxide by a crystallization reaction is provided. The method includes: a nucleation step of performing nucleation by controlling a pH of an aqueous solution for nucleation including metal compounds containing nickel, cobalt and manganese, and an ammonium ion donor to 12.0 to 14.0 in terms of the pH as measured at a liquid temperature of 25° C. as a standard; and a particle growth step of growing nuclei by controlling a pH of an aqueous solution for particle growth containing nuclei formed in the nucleation step to 10.5 to 12.0 in terms of the pH as measured at a liquid temperature of 25° C. as a standard.

The present invention relates to a solid catalyst component for alpha-olefin polymerization having a narrow particle size distribution of not less than 6.0 in terms of the value of N in a Rosin-Rammler function of particle size distribution and giving a catalytic activity of not less than 10,000 ((g-polymer produced / g-solid catalyst component) / hour) in polymerization. The catalyst component is obtained by a process which comprises reducing a titanium compound with an organomagnesium compound in the presence of an organosilicon compound and an ester to obtain a solid product, then treating the solid product with: (a) a mixture of titanium tetrachloride and an ether, (b) an organic acid halide, and (c) a mixture of titanium tetrachloride and an ether optionally containing an ester.

The invention provides a method for continuously synthesizing a precursor of a lithium ion battery positive material, relating to an improvement of a synthesis method of a nickle cobalt manganese termary positive material nickle cobalt lithium manganate of the lithium ion battery positive material. The method is characterized in that the synthesis process is as follows: merging a complexing agent ammonia, an aqueous solution of metal nickle cobalt manganese ions and a precipitator sodium hydroxide solution and then continuously adding the substances into a reaction kettle for a synthesis reaction under the strong stirring condition in the presence of protective gas; and aging, filtering and washing the effluent from the reaction kettle, and then drying to obtain the lithium ion battery positive material precursor spherical nickle cobalt manganese termary hydroxide. The method has the advantages that the preparation process is continuous, the particle size of the prepared nickle cobalt manganese compound hydroxide powder is controlled in a range of 5-20 microns, and the prepared nickle cobalt manganese compound hydroxide powder is even in distribution and excellent in electrochemistry property. The method has the advantages of high production efficiency, low production cost and significant economic and social benefits, and the energy is saved.

A process comprising aggregating a colorant encapsulated polymer particle containing a colorant with colorant particles and wherein said colorant encapsulated latex is generated by a miniemulsion polymerization.

The invention relates to a non-noble metal supported selective hydrogenation catalyst and a preparation method and application thereof. The catalyst comprises a carrier, and a main active component and an auxiliary active component which are loaded on the carrier, wherein the main active component is nickel, and the auxiliary active component is at least one of Mo, La, Ag, Bi, Cu, Nd, Cs, Ce, Zn and Zr; and the active components exist in amorphous forms, the average grain diameter is less than 10 nanometers, and the catalyst is prepared by a micro-emulsion method. The catalyst has evenly distributed active components and high dispersity, and can resist the erosion of poisonous materials of arsenium, sulfur and the like. The catalyst has good hydrogenation performance which is higher than that of the prior level of the conventional non-noble metal catalyst and is close to the level of a noble metal Pd catalyst in the reaction for removing acetylene hydrocarbon through C2 selective hydrogenation.

The invention relates to a manufacturing method for nanometer rod film of zinc oxide on fiber product, comprising (1) by sol-gel method ZnO nano-crystal grain is prepared and a great deal of ZnO seed crystal is deposited on the surface of fiber product, molar concentrations of zinc salt and alkaline agent are all 0.001M-0.75M; (2) by hydrothermal method or precipitation of chemical solution pool, nanometer rod film of zinc oxide grows on fiber product, molar concentrations of zinc salt solution and complexing agent solution are all 0.001M-0.05M; ZnO nanometer rod film with equal surface and good directivity is obtained. The manufacturing method is provided with simple method and low cost. It is suitable for industrial production.

The invention discloses a preparation method of mesophase carbon microspheres from coal liquefaction residues serving as raw materials, which comprises the following steps of: firstly carrying out solvent extraction on the coal liquefaction residues, then carrying out a series of processing to obtain refined asphalt with different contents of quinoline insoluble substances, and carrying out thermal polycondensation reaction on the refined asphalt in the presence of a chemical auxiliary agent and a nucleating accelerator at the temperature of 380-450 DEG C, the pressure of 0-5 MPa and the stirring rotation speed of 40-500 r / min for 1-20 hours to obtain the mesophase microspheres. According to the invention, the chemical auxiliary agent and the nucleating accelerator can be added during theheat treatment process to improve the yield and narrow the particle size distribution of the mesophase carbon microbeads, and the mesophase carbon microspheres are prepared from the coal liquefactionresidues serving as the raw materials and have the advantages of low cost, simple preparation process, high yield (up to 35%), narrow particle size distribution, good sphericity, etc.

A plasma aided high-energy ball grinding method includes such steps as installing the front cover plate and rod electrode of ball grinder, respectively connecting the ball grinder and rod electrode to the poles of plasma power supply, loading the powder to be ground in the ball grinder, pumping negative pressure, filling discharging gas medium, turning on the plasma power supply, regulating discharge parameters for corona discharge or glow discharge, and turning on the motor to drive the vibration exciting block for ball grinding.

The invention belongs to the technical field of bioseparation material, in particular to a magnetic composite microsphere with nucleocapsid structure and a preparation method thereof. Nano ferroferric oxide decorated by oleic acid is firstly used as raw material, and is polymerized through template fine emulsion so as to prepare the monodisperse magnetic composite microsphere with high magnet content; and then the monodisperse micosphere is polymerized through seed emulsion and is added with different amount of shell monomer to prepare the magnetic composite microsphere with the nucleocapsid structure and the magnet content of 20wt percent to 80wt percent. The grain size of nucleocapsid composite microsphere is in narrow distribution, and the magnet content of the microsphere is controllable and the surface has functional reactive group; therefore, the microsphere of the invention can be surface-modified into a magnetic carrier of biological active molecule by chemical crosslinking to be applied in the biomedicine field. The method of the invention can be simply operated and the process of which can be controlled, thus having industrialized prospect.

The invention discloses a vanadium-phosphorus-oxygen catalyst, and a preparation method thereof. According to the preparation method, a nano vanadium phosphorus oxide is taken as a precursor, is subjected to activating and then moulding, or is subjected to moulding and then activating so as to obtain the vanadium-phosphorus-oxygen catalyst; grain size of the nano vanadium phosphorus oxide is less than 100nm, and by volume, particles with a grain size of 30 to 50nm accounts for 7 to 14%, particles with a grain size of 50 to 70nm accounts for 54 to 79%, and particles with a grain size more than 70nm accounts for 7 to 39%. According to the vanadium-phosphorus-oxygen catalyst prepared by taking the nano vanadium phosphorus oxide as a precursor, octahedral structure of (VO)2P2O7 is neater, catalyst structure is stable, and catalytic activity and catalyst stability are higher. When the vanadium-phosphorus-oxygen catalyst is used for catalytic preparation of maleic anhydride via oxidation of n-butane, n-butane conversion rate reaches 87 to 95mol%, and maleic anhydride selectivity reaches 72 to 84mol%.

The invention provides a chemical-mechanical abrasive composition for use in semiconductor processing, which comprises an aqueous medium, an abrasive, and an abrasion accelerator. The abrasion accelerator mainly functions to enhance the removal rate of the substances to be removed, and selected from the compounds of the following formula, the acid-addition salts thereof, or mixtures of two or more of the foregoing compounds and salts:wherein X and Y are independently lone-pair electrons containing atoms or atomic groups; and R1 and R2 are independently H, alky, amino, aminoalkyl, or alkoxy. The chemical-mechanical abrasive composition of the invention may optionally comprise an acidic component and / or a salt thereof, so as to further enhance the abrasion rate. The invention further provides a method of using the above chemical-mechanical abrasive composition for polishing the surface of a semiconductor wafer.

The invention relates to a compatibilizing dispersant used in a slurry composition comprising a strongly cationic component and a strongly anionic component. More specifically, the invention relates to stable aqueous slurries comprising suspended particles of sparingly soluble salts, oxide, and / or hydroxides of copper and / or zinc. The slurry further comprises a quaternary amine compound present in a biocidally effective amount when the slurry is used in a manner that provides the sparingly soluble copper and / or zinc containing particles in a biocidally effective amount. The slurry further comprises an effective amount of a dispersant having a large non-ionic component.

Disclosed are compositions of ethylene acid copolymers and polyamides that are useful for fabricating films, sheets and molded articles for scuff and scratch resistant material and their application as decorative and protective films, comprising (1) from about 30 to about 65 weight % of a polyamide; and (2) from about 70 to about 35 weight % of a copolymer of (a) ethylene; (b) from about 5 weight % to about 15 weight % of an α,β-unsaturated C3-C8 carboxylic acid; (c) from about 0.5 weight % to about 12 weight % of at least one comonomer that is an ethylenically unsaturated dicarboxylic acid; and (d) from 0 weight % to about 30 weight % of monomers selected from alkyl acrylate and alkyl methacrylate, wherein the alkyl groups have from one to twelve carbon atoms; at least partially neutralized by one or more alkali metal, transition metal, or alkaline earth metal cations. Articles prepared from these compositions, such as films, show high toughness, good mechanical properties, excellent scratch and scuff resistance and, most importantly, good optical properties. More particularly, the compositions of ethylene copolymers and polyamides of the present invention can be used as protective coatings or layers on scuff- and scratch-exposed objects.

The invention relates to a microflow droplet technology-based method for one-step continuous preparation of multi-chamber calcium alginate microgel for immobilization of bioactive substances. The method realizes high-throughput continuous production of a microgel material. The method comprises forming a parallel and stable flow field through different hydrogel prepolymer solutions in a microfluidic channel, pouring the hydrogel prepolymer solutions for forming different chambers of the microgel into a microfluidic chip to form water phase solutions of multiple phase parallel fluids, mixing thewater phase solutions and an immiscible fluid (oil phase) through a T-shaped channel or a fluid focusing design to obtain water-in-oil emulsion drops and then alginic acid in the drops is linked immediately so that multi-chamber microgel is prepared, and cleaning the emulsion drops on the microfluidic chip so that the microgel is fast conveyed into a water phase. The method realizes one-step preparation of the calcium alginate microgel immobilized with bioactive substances and is suitable for industrial application.

The invention belongs to the technical field of preparing a metal powder material and provides a gas atomization preparing method for micro spherical metal powder and equipment thereof. The preparing method comprises the technological process of smelting a material, driving molten metal jet flow through positive pressure, atomizing gas, carrying out cooling, collecting powder, detecting performance, and carrying out screening, packaging and the like, by reducing the outlet hole diameter of a flow guide nozzle, inert gas is reversely filled into a smelting chamber to certain positive pressure, the smelting chamber in the gas atomizing equipment is designed into a pressure container, a locking sealing device is adopted in the connecting portion of a furnace cover and a furnace body, the smelting chamber and an atomizing tank are designed into cavities which are isolated mutually and communicate only through the flow guide nozzle, and the fine powder yield of the metal powder is effectively increased. Compared with the existing gas atomizing metal powder preparing technology, the fine powder yield of the metal powder prepared by the utilization of the method is high, size distribution is narrow, the sphericity degree is good, the oxygen content is small, atomized gas consumption is low, and the technology equipment is simple, high in continuity and suitable for industrialized production and can be widely applied.

The invention relates to a method for preparing nano iron phosphate, belonging to the technical field of the preparation of lithium ion battery cathode materials. The method is characterized by comprising the following steps: inputting an alkaline aqueous solution and a mixed solution formed by one of phosphoric acid or a soluble phosphate solution, one of a water-soluble ferrous salt solution and an oxidant or a ferric salt solution and a water-soluble dispersing agent into a rotating packed bed layer by a metering pump at a certain feeding speed; regulating the rotating speed of the rotating packed bed and controlling the pH value of the reaction system by an alkaline solution; discharging nano iron phosphate particles generated by reaction crystallization from a discharge hole of the rotating packed bed along with the mixed solution; and filtering, washing and drying the nano iron phosphate particles to obtain nano iron phosphate (FePO4.2H2O) powder. The method is simple and has easy operation and high efficiency, and the prepared iron phosphate reaches the nano grade, has uniform particle size and narrow distribution range and is suitable for industrialized production. The nano iron phosphate is a good precursor material for preparing lithium iron phosphate which is used as a cathode material of high-power type lithium ion batteries.

The invention relates to magnetic silicon dioxide microspheres with a nuclear shell and surface anisotropic double functional groups and a preparation method thereof. The preparation method comprises the following steps of: preparing superparamagetic microspheres by a solvothermal process; preparing magnetic microspheres which are coated by silicon dioxide by a sol-gel process; preparing the magnetic silicon dioxide microspheres of which the surface has amino group by taking the magnetic silicon dioxide microspheres as seeds and by the copolycondensation of alkyl ester orthosilicate and a silane coupling agent, and drying the magnetic silicon dioxide microspheres to obtain samples; and by a PICKERING emulsion technology, stabilizing a paraffin / aqueous emulsion system with a micrometer scale by using the aminated magnetic microspheres to form single-layer close packing of the magnetic microspheres on the surface of paraffin spheres, then reacting the amino group on the surface of the magnetic microspheres which is exposed in a liquid phase with succinic anhydride to introduce carboxyl into the partial surface of the microspheres, so that the surfaces of the magnetic microspheres have the anisotropic double functional groups. The obtained magnetic microspheres with the double functional groups have the advantages that: magnetic responsiveness is high; grain size can be controlled between 200 and 800 namometers; and the density of the surface functional groups can be adjusted.

Disclosed are: nickel complex hydroxide particles that have small and uniform particle diameters; and a method by which the nickel complex hydroxide particles can be produced. Specifically disclosed is a method for producing a nickel complex hydroxide by a crystallization reaction, which comprises: a nucleation step in which nucleation is carried out, while controlling an aqueous solution for nucleation containing an ammonium ion supplying material and a metal compound that contains nickel to have a pH of 12.0-13.4 at a liquid temperature of 25° C.; and a particle growth step in which nuclei are grown, while controlling an aqueous solution for particle growth containing the nuclei, which have been formed in the nucleation step, to have a pH of 10.5-12.0 at a liquid temperature of 25° C. In this connection, the pH in the particle growth step is controlled to be less than the pH in the nucleation step.

In at least one embodiment, a particulate water-absorbing agent is provided which not only ensures the many conventional physical properties (absorption rate, centrifuge retention capacity, absorbency against pressure, particle size distribution etc.) but also prevents odor which is generated after the resin is swollen by absorption. The water absorbent agent of an embodiment of the present invention therefore does not cause odor in actual use. As a result of intensive study of the foregoing problem, an embodiment of the present invention offers a way of controlling a specific odor component, which is generated from impurities and / or by-product derived from the raw material, after the high temperature process. In this way, an embodiment of the present invention successfully provides a water absorbent agent not causing odor after the resin is swollen by absorption.

The invention relates to a latent microcapsule curing agent initiating thermosetting epoxy resin curing at medium temperature and a preparation method of an adhesive thereof. The latent microcapsule curing agent is technically characterized in that the high-activity medium temperature curing agent is taken as a core material, thermoplastic high polymer microspheres are taken as a wall material, the solvent evaporation technology is adopted for preparing the latent microcapsule curing agent with better curing performance and latent performance, and the latent microcapsule curing agent can be applied to an epoxy resin system for preparing the single-component medium temperature curing epoxy resin adhesive. Microcapsules prepared by the method are high in capsule core content, smooth in surfaces, narrow in particle size distribution and good in compatibility with matrix epoxy resin and can be better dispersed in the epoxy resin; and the prepared single component adhesive can realize curing at the medium temperature, the storage period at room temperature is longer and the tensile shear strength performance can be further improved.

The invention relates to a method for preparing a ternary cathode material precursor by recycling a lithium-ion battery material. The method comprises the following steps: recycling a lithium-ion battery cathode material with sulfuric acid and hydrogen peroxide to obtain a first solution; adjusting the pH value of the first solution to be 5-6.5, adding a filter aid and filtering out impurities to obtain a second solution; adding nickel sulfate, cobalt sulfate and / or manganese sulfate to the second solution, adjusting the molar ratio of nickel to cobalt to manganese to be (0.4-0.6) to (0.1-0.3) to (0.2-0.4) to obtain a third solution; adding a complex precipitant to the third solution, adjusting the pH value of the third solution to be 7-9, and reacting to obtain a nickel-cobalt-manganese ternary material precursor sediment; and washing and drying the nickel-cobalt-manganese ternary material precursor sediment to obtain the ternary cathode material precursor. The method is high in recovery rate; the recycling process is simple; and the prepared ternary cathode material precursor is high in purity, small in particle size, narrow in distribution and even to mix.

The invention discloses a spherical silver powder, wherein the particle size distribution range of the spherical silver powder is 0.1-5 mum, and the D50 particle size is 1.0-3.5 mum; the tap density of the spherical silver powder is greater than 3.6 g / cm<3>; and the specific surface area of the spherical silver powder is less than 1.0 m<2> / g. The preparation method for the spherical silver powder comprises the following step of: with L-ascorbic acid as a reductive agent and polyvinylpyrrolidone as a protective agent, reducing silver out of a reaction material, namely silver nitrate solution, by a chemical reduction method, wherein the pH value of the reaction system is controlled to be constant between 3 to 6 during the whole reaction process of the chemical reduction method, so as to keep the speed of the reduction reaction for silver nitrate stable. The spherical silver powder disclosed by the invention is narrow in particle size distribution range, excellent in dispersity, high in tap density, small in specific surface area, and especially suitable for preparing a silver paste for the electrode of a solar cell and the electrode of a plasma displayer.

A process for preparing zirconium oxide nano-particles used for coated thermal barrier layer includes such steps as preparing the mixed solution of zirconium oxychloride and yttrium oxide (or chloride), adding ammonia water, washing for dispersing, hydrothermal reaction to generate Y-stabilized ZrO2 nano-particles, separating, coating by aluminium oxide, drying, granulating and heat treating.

The invention discloses a preparation method of a lithium-stored composite material Fe3O4 / C with a hollow sphere structure and an application of the lithium-stored composite material Fe3O4 / C with a hollow sphere structure in a lithium ion battery, belonging to the technical fields of material synthesis and high-energy lithium-ion storage batteries. The preparation method is characterized in that a solvothermal method or hydrothermal method is utilized to prepare the Fe3O4 / C composite material with a hollow sphere and narrower particle size distribution, wherein the Fe3O4 / C composite material is high in purity; and the mean particle size of the Fe3O4 / C composite material is 750 nanometers and the wall thickness of the Fe3O4 / C composite material is 250 nanometers. An electrochemical test proves that the first discharging specific capacity of the Fe3O4 / C composite material prepared by the method can be 1157mAh / g, and the discharging specific capacity of the Fe3O4 / C composite material can be 900mAh / g after being circulated for 65 times, thus showing the perfect cyclical stability. The Fe3O4 / C composite material has good rate performance; and the charging specific capacity of the Fe3O4 / C composite material is 620mAh / g and 460mAh / g respectively under 2C and 5C charge-discharge rates, thus the rate performance is superior to that of an existing commonly-used carbon cathode material (theoretical specific capacity is 372mAh / g). The Fe3O4 / C lithium ion battery cathode material is low in cost, simple in process and easy to industrialize, and has wide application prospects in the high-energy lithium ion battery field.

A process for preparing nano-zinc oxide includes such steps as dissolving soluble Zn salt and urea in water, microwave radiating while reacting by homogenizing-depositing method to obtain the deposit of alkaline zinc carbonate, vacuum drying, ball grinding, calcining to obtain the crystal grains of nano-zinc oxide, mixing with surface modifier, organic solvent and disperser, ball grinding, and microwave radiating which surface modifying.