238results about How to "Fine and uniform particles" patented technology

The invention relates to a cross bonding sodium hyaluronate gel for injection and a preparation method thereof. The method is characterized in that sodium hyaluronate and glycidyl ether are mixed and react in alkaline solution to form water-insoluble gel, the gel is purified in deionized water and broken into particles of certain sizes; ionic strength of the deionized water is improved to contract the gel particles. The cross bonding sodium hyaluronate gel features asepsis, apyrogeneity and small and uniform particles; therefore the gel can be applied to prepare injection for beauty care and medical treatment.

The invention relates to a nanometer molten binary nitrate heat-transfer heat-storage medium and a preparation method thereof and belongs to the field of solar photo-thermal electricity generation. The nanometer molten binary nitrate heat-transfer heat-storage medium is characterized in that nano-particles are dispersed in a KNO3-NaNO3 and KNO3-NaNO2 solid-liquid phase-change molten binary nitrate system at a high temperature so that the nanometer molten binary nitrate heat-transfer heat-storage medium is compounded, and the nano-particles comprise SiO2, ZnO, Al2O3, TiO2, CaO and/or MgO nanoparticles. The nanometer molten binary nitrate heat-transfer heat-storage medium solves the problem that the existing nanometer molten binary nitrate system has a low heat conductivity coefficient, poor heat stability and a narrow use temperature scope and can be widely used in the technical field of solar photo-thermal electricity generation.

The invention relates to a preparation method for antimony-doped tin oxide powder. The preparation method comprises the following steps of mixing antimony trichloride, tin tetrachloride pentahydrate and a compounding ingredient, adding into a hydrochloric acid solution, and uniformly stirring a mixed solution to obtain transparent liquid; uniformly mixing a dispersing agent, tin tetrachloride pentahydrate, water and ethanol to obtain a base solution; dropwise adding the transparent liquid and an ammonium hydroxide precipitating agent into the base solution within 30 to 80 minutes in a double titration way, controlling reaction temperature to be 50 to 60 DEG C while stirring, and controlling final reaction pH to be 5 to 6; stopping stirring after titration, and performing curing to obtain precursor suspension; performing filtration, water washing, alcohol washing, azeotropic distillation, drying, grinding and calcination on obtained precursor precipitates. According to the method, tin and antimony are synchronously hydrolyzed and precipitated, and antimony is uniformly doped; the powder prepared by the method has the advantages of small particle size, loose structure, low agglomeration rate, high dispersibility and the like.

The invention discloses a quenching and tempering device for cooling high-temperature fume, comprising a two-fluid electrical appliance controller, a water path and an air path arranged between a high-temperature fume inlet and a high-temperature fume outlet. The device of the invention is characterized in that a low pressure pump is arranged in the air path, a low pressure air path is combined into a water pipeline before a spray gun, two transducers are arranged to adjust the pressure and flow of a water pump and an air pump, the nozzle bore diameter is phi 6-7mm, and the spray particle diameter is smaller than 300 micrometers; a temperature sensor is respectively arranged at a wetting tower inlet and the fume outlet, and the outlet temperature is controller to 130-150 DEG C; an operation program is controlled to calculate the temperature difference of the fume inlet temperature and the fume outlet temperature, tower volume and spray fall height; two transducers are used for controlling the water pump and the air pump to automatically adjust operation power when low air pressure is 0.4-0.6MPa, and air flow quantity and water flow quantity are 5-25T/H. the particle diameter of sprayed water spray is small and even, which can better realize precise control to temperature and reduces atomization particle residence time and wet bottom danger. The dust removal device designed by the invention increases fume density and volume, lowers speed and improves dust removal function. In particular, the spray granularity is small, which can obviously control temperature and humidity, lower discharge Dioxin and furan mixed in dust and reduce environment protection cost.

The invention discloses a light emitting diode (LED) fluorescent powder with single matrix white light excited by near ultraviolet and a preparation method thereof, the chemical formula of fluorescent powder is that: NM1-x-y-zPO4:xR, yG, zB, wherein N is freely selected from at least one of a group formed by Li, Na and K; M is freely selected from at least one of a group formed by Mg, Ca, Sr, Ba and Zn; R is freely selected from at least one of a group formed by Mn and Sm; G is Tb; and B is freely selected from at least one of a group formed by Ce and Eu, and x is higher than 0 but lower than 0.25, y is higher than 0 but lower than 0.25, and z is higher than 0 but lower than 0.25. The particle size of the prepared fluorescent according to the method provided by the invention is small and uniform, doping of fluorescent material activator on a molecule level is realized, three bands of red, green and blue can be emitted by excitation of near ultraviolet of 350-410nm, the color display index is high, and can be used in the white light LED excited by near ultraviolet.

The present invention discloses a wax emulsion for treating board for making pencil. Said wax emulsion is made up by using mineral wax, sterilizing agent, adjuvant, emulsifier, preservative and water according to a certain mixing ratio. The cutting face of the pencil made of the board treated by said wax emulsion is smooth and clean, and said invented wax emulsion can greatly raise quality of the product. As compared with dry board-baking wax-impregnating method said invented method can reduce consumption of wax-like material, also can reduce environmental pollution due to dry baking wax-impregnating method.

The invention discloses small-particle yellow rare-earth fluorescent powder and a preparation method and a purpose of visualizing a latent fingerprint thereof. The general structure formula of the fluorescent powder is Y3-x-yCexGdyA15O12, wherein the x is not less than 0.1 and no larger than 0.4, y is no less than 0.1 and no larger than 0.4 and the particle size is between 1.5 to 3 Mum. The preparation method comprises the steps of weighing up raw materials according to the stoichiometric ratio of the structure formula, grinding and evenly mixing up the raw materials, sintering the raw materials with high-temperature solid-phase method to obtain powder and obtaining the small-particle yellow rare-earth fluorescent powder by adopting an ultrasonic dispersion technology after the powder goes through a mesh with 300 to 400 eyes. The small-particle yellow rare-earth fluorescent powder can be applied to visualizing the latent finger print after being amido-functionalized by gamma-Aminopropyl triethoxy silane and being mixed with reduced iron powder which goes through a mesh according to a certain ratio. The fluorescent powder provided by the invention has even and small particles, high fluorescent intensity, the excitation wave length between 460 to 480nm which is within the range of the light source commonly used in criminal investigation and the emission wave length between 520 to 570nm, is conducive to visualizing the latent finger print on the site and eliminating the disturbance of the object background and is important for establishing a high-efficient, non-toxic, lossless and convenient finger print visualizing method.

The invention discloses an O2 configured lithium battery positive electrode material and a preparation method thereof. The material is mainly of an O2 configured stratified structure, and comprises lithium ion layers, transitional metal layers and oxygen atom layers, wherein the oxygen atom layers are arrayed periodically by taking the interval of the two transitional metal layers as a period; andthe chemical formula is Lia(LixMy)O2, wherein M is selected from one or more of Mn, Ni, Co and Fe, a is more than or equal to 5/6 and smaller than or equal to 1, x is more than or equal to 0.2 and smaller than or equal to 0.35, and x+y is equal to 1. The performance is extremely excellent, first coulombic efficiency is between 95%-105%, the reversible capacity is up to 398mAh/g under 10mA/g multiplying power, the phase change from a stratified phase to a spinel phase cannot occur in the circulation, and the synthetic method is simple and convenient for industrialized mass production.

This invention discloses a preparation of low molecular weight teflon, it adopts emulsion polymerization method, utilizing deionized water as polymerization medium, utilizing Perfluorooctanoic acid as dispering agent, utilizing dichlormethane as chain transfer agent, tetafluoroethylene metamer is polymerized by utilizing persulfate as initiator. Low molecular weight Teflon is gained by agglomerating and continuously drying polymerization solution, this invention can prepare low molecular weight PTFE resin which is water-galact typus and excellent constance, it is completely suitable for follow-up manipulation and continuous operation. it can be extently enlarged, spray drying technology is energy saving and save time, directly obtained particle is thin and uniform and spherical, molecular weight distributes between 4-8*103, it has a good dispersibility for other composition, it can completely be suitable to prepare composite of low molecular weight PTFE resin whose specification is that every composition is easy to be mixed uniformly and permanent.

The invention discloses a silver paste for an electrode of a solar cell and a method for preparing the silver paste. The silver paste comprises the following components by mass percent: 60-85% of silver powder, 8-12% of glass powder, 7-20% of organic phase, 2-8% of organic solvent and 0.1-3% of oxide additive. The silver paste disclosed by the invention has the advantages of excellent high-temperature firing performance; and the electrode fired by the silver paste has high precision and excellent conductivity and is suitable for being applied to battery assemblies with higher photoelectric conversion efficiency.

The invention provides a preparation method of nano-manganese oxide which is of a nanowire net structure. The preparation method comprises the following steps: dropwise adding an oxidant containing aqueous solution or feeding oxidizing gas into an active agent containing manganese salt aqueous solution, and uniformly dispersing; carrying out a liquid-phase co-precipitation reaction, so that nano-sized manganese dioxide is suspended in the solution; filtering the solution; and washing and drying the obtained precipitate subjected to filtering, so that the nano-manganese oxide is obtained. The nano-manganese oxide prepared by using the preparation method disclosed by the invention can be applied to the field of super capacitors and wastewater treatment. According to the invention, through elaborate design, the industrial process is maximally simplified, the quality of products is improved, and the production cycle is shortened, therefore, the method disclosed by the invention is a nano-manganese oxide preparation method which is simple in technological process, small in energy consumption, short in reaction period, good and stable in product quality and low in cost.

The invention provides a preparation method for cathode active material titanic oxides (H2Ti12O25) of a lithium ion battery; and the preparation method comprises the following steps of: mixing an alkali metal salt and alkoxy titanium hydrolytic sol; drying and roasting an obtained sol so as to obtain a precursor M2Ti3O7 (M is alkali metal); carrying out proton exchange on the precursor M2Ti3O7 prepared in the step a) and hydrochloric acid, so as to obtain H2Ti3O7; and carrying out heat treatment on the H2Ti3O7 prepared in the step b), so as to obtain a target product H2Ti12O25. The titanium oxide H2Ti12O25 prepared by the method provided by the invention has the advantages of good rate capability and high cycling stability; and by using the material as an electrode active material, the lithium ion battery with excellent cycle performance can be prepared.

The invention discloses a method for preparing precursors of lithium titanate and lithium iron phosphate by comprehensively using ilmenite, which comprises the following steps of: 1) separating the ilmenite, namely crushing the ilmenite, leaching the ilmenite with hydrochloric acid, filtering the ilmenite to obtain a residue and a filtrate; 2) preparing the precursor of the lithium titanate, namely washing the residue prepared by step 1) with the hydrochloric acid, adding the washed residue in aqueous alkali, cooking the mixture, filtering the mixture after cooling, and then adding the obtained filter residue in the hydrochloric acid, cooking the mixture, and filtering, washing, drying and calcining the mixture after cooling to obtain the precursor of the lithium titanate; and 3) preparing the precursor of the lithium iron phosphate, namely taking the filtrate prepared by step 1) as a raw material, adding iron powder to reduce ferric iron, diluting the reduced filtrate, adding a complexing agent and a precipitant into the diluted mixture, controlling the pH value of the system, reacting the mixture at 30 to 80 DEG C, aging the reacted mixture, and filtering, washing and drying the obtained precipitate to obtain the precursor of the lithium iron phosphate. The method is wide in raw material source, simple in process flow, good and stable in product quality, low in cost and comprehensive and full in use of the ilmenite.

The invention discloses a Chinese herbal medicine extraction method with high extraction rate, which comprises the following steps: raw material selection: selecting and weighing corresponding Chineseherbal medicines according to extraction requirements, adding water required by proportioning according to the weight of the Chinese herbal medicines, and adding raw materials by adding the Chinese herbal medicines into an extraction tank through a uniform feeding mechanism; meanwhile, adding a small amount of water into the extraction tank through a cold water adding pipe, and after the Chineseherbal medicine is soaked for a period of time, carrying out active component extraction, wherein the effective components in the Chinese herbal medicine are gradually separated out into the water inthe decocting process. According to the traditional Chinese medicine extraction device, the liquid exchange efficiency in the medicinal materials is improved by actively and repeatedly mechanically squeezing the decocted medicinal materials, so that effective components in the medicinal materials are diffused into liquid medicine in the liquid exchange process, the decocting time and the decoctingfrequency of traditional Chinese medicines are shortened, and the extraction efficiency of the traditional Chinese medicines is effectively improved.

The invention discloses a plate-shaped Al2O3 particle making method and dimension control method in the fine chemical domain, which comprises the following steps: taking partial decomposed aluminum salt as Al2O3 pioneer body; making the Al2O3 particle through fused salt method; controlling the particle dimension precisely through adding plate-shaped Al2O3 seed in the raw material powder; making the dimension of Al2O3 particle between sub-micron and several micron.

The invention relates to a method for preparing a lithium manganese phosphate positive material of a lithium battery by spray pyrolysis and belongs to the technical field of the positive materials of lithium batteries. According to the method, homogeneous nucleation of lithium manganese phosphate is promoted through the high-temperature spray pyrolysis under the condition of an inert atmosphere, so as to reduce the temperature and the time of the follow-up reaction to obtain the lithium manganese phosphate positive material with excellent electrochemical performance. The method disclosed by the invention is simple; and since raw materials are mixed in molecular ion level and the temperature and the time of the follow-up reaction are reduced after the high-temperature spray pyrolysis, the obtained lithium manganese phosphate material has the advantages of high purity, complete crystal structure, fine and uniform particles and the excellent electrochemical performance.

The invention discloses a modified hyperbranched polyamide-amine asphalt emulsifier and a preparation method and application thereof. The preparation method comprises the following steps: (1) an AB2 type monomer is synthesized by Michael addition reaction between diethylenetriamine and methyl acrylate, and the molar ratio of diethylenetriamine to methyl acrylate is (1:1)-(1:1.2); (2) hyperbranched polyamide-amine is synthesized by self melt polycondensation reaction of the AB2 type monomer; and (3) amidation reaction between the hyperbranched polyamide-amine and oleic acid is performed, the molar ratio of hyperbranched polyamide-amine to oleic acid is (1:1)-(1:1.2). The modified hyperbranched polyamide-amine as an asphalt emulsifier can meet hydrophilic lipophilic balance value demand, and significantly reduces the critical micelle concentration value, and prepared asphalt emulsion is fine and uniform in particle, and can meet the requirements on storage stability, particle size and weight of screen residue.

The invention provides a preparation method of a lithium silicate material with high purity, which comprises the steps of: firstly, mixing absolute ethyl alcohol and ammonia water into a mixed solution with pH of 8-11, adding tetraethoxysilane into the mixed solution of the ammonia water and the absolute ethyl alcohol step by step according to the proportion of the tetraethoxysilane to the absolute ethyl alcohol of 1:15-1:60 in volume ratio, and stirring to obtain liquid A; then weighing a lithium source according to the mol ratio of Li:Si of 2:1, dissolving into the absolute ethyl alcohol, adding a prepared lithium salt mixed solution into the mixed solution A to generate a suspension solution B; and drying the suspension solution B and then placing into a high temperature furnace for heat treatment, and cooling the dried suspension solution B to the room temperature with the furnace to obtain the lithium silicate material with high purity. The method has the advantages of simple process, low synthesis temperature and low cost; and the synthesized lithium silicate powder has uniform and thin powder particle, better crystallinity and no impurity phase and is a higher-purity lithium silicate material. The lithium silicate (LiSiO3) material can be used for the fields of a coating material, a lithium battery raw material, a breeder reactor material, and the like.

The invention discloses a method for one-step synthesis of iron fluoride/C, and belongs to the technical field of lithium ion batteries. The method disclosed by the invention comprises the following steps of fully mixing and grinding ferrous oxalate and excessivepowdered polytetrafluoroethylene, loading a uniform mixture in an aluminum oxide crucible, and roasting the uniform mixture in an argon environment, wherein the roasting temperature is 500-650 DEG C, and the temperature is maintained for 1-3 hours; cooling the uniform mixture with a furnace to a room temperature after roasting to obtain a roasted product, namely iron fluoride/C; and taking out the product, and grinding the product to obtain fine nanometer iron fluoride/C powder. The nanometer iron fluoride/C prepared according to the method has the advantages that the particle size is small and uniform, and iron fluoride is closely wrapped by carbon; and the heat preservation time in the roasting process is relatively short, and uniform and fine particles are ensured and are prevented from growing up.

The invention provides a catalyst used in preparation of acrylic acid through one-step oxidation of propylene and a preparation method thereof, which relates to a catalyst and a preparation method thereof. A basic general formula of the catalyst is Mo1VaTebNbcAeBfO/yZ, wherein Mo is molybdenum, V is vanadium, Te is tellurium, Nb is niobium, A is at least one selected from the group consisting of phosphorus, boron, iron, tungsten and the like, B is at least one selected from the group consisting of potassium, cerium, caesium and the like, Z is SiO2 or Al2O3, a, b, c, d, e, f and y respectively represent mol ratios of every element, a is in a range of 0.2 to 0.6, b is in a range of 0.1 to 0.6, c is in a range of 0.01 to 0.2, d is in a range of 0.01 to 0.2, e is in a range of 0 to 0.05, f is in a range of 0 to 0.08, and y is in a range of 0 to 3. When the catalyst is applied to preparation of acrylic acid through one-step oxidation of propylene, the conversion rate of propylene is 78 to 92%, and selectivity of acrylic acid is 79 to 90%. The catalyst prepared by using the method has high activity, good selectivity and stable performance.