3409results about "Zinc oxides/hydroxides" patented technology

Disclosed is a method of exfoliating a layered material (e.g., graphite and graphite oxide) to produce nano-scaled platelets having a thickness smaller than 100 nm, typically smaller than 10 nm, and often between 0.34 nm and 1.02 nm. The method comprises: (a) subjecting the layered material in a powder form to a halogen vapor at a first temperature above the melting point or sublimation point of the halogen at a sufficient vapor pressure and for a duration of time sufficient to cause the halogen molecules to penetrate an interlayer space of the layered material, forming a stable halogen-intercalated compound; and (b) heating the halogen-intercalated compound at a second temperature above the boiling point of the halogen, allowing halogen atoms or molecules residing in the interlayer space to exfoliate the layered material to produce the platelets. Alternatively, rather than heating, step (a) is followed by a step of dispersing the halogen-intercalated compound in a liquid medium which is subjected to ultrasonication for exfoliating the halogen-intercalated compound to produce the platelets, which are dispersed in the liquid medium. The halogen can be readily captured and re-used, thereby significantly reducing the impact of halogen to the environment. The method can further include a step of dispersing the platelets in a polymer or monomer solution or suspension as a precursor step to nanocomposite fabrication.

A process for the production of ultrafine powders that includes subjecting a mixture of precursor metal compound and a non-reactant diluent phase to mechanical milling whereby the process of mechanical activation reduces the microstructure of the mixture to the form of nano-sized grains of the metal compound uniformly dispersed in the diluent phase. The process also includes heat treating the mixture of nano-sized grains of the metal compound uniformly dispersed in the diluent phase to convert the nano-sized grains of the metal compound into a metal oxide phase. The process further includes removing the diluent phase such that the nano-sized grains of the metal oxide phase are left behind in the form of an ultrafine powder.

Doped, pyrogenically prepared oxides of metals and / or non-metals which are doped with one or more doping components in an amount of 0.00001 to 20 wt. %. The doping component may be a metal and / or non-metal or an oxide and / or a salt of a metal and / or a non-metal. The BET surface area of the doped oxide may be between 5 and 600 m2 / g. The doped pyrogenically prepared oxides of metals and / or non-metals are prepared by adding an aerosol which contains an aqueous solution of a metal and / or non-metal to the gas mixture during the flame hydrolysis of vaporizable compounds of metals and / or non-metals.

The invention relates to a method for preparing continuous graphen / zinc oxide composite structure in large area, which belongs to the preparation field of the novel nanometer material, and is applicable to the fields such as sensor, solar panel, novel nanometer part and the like. The method comprises the following three steps that: first step: uniformly dispersing graphen or graphene oxide in liquid phase; second step: utilizing a hydrothermal process to ensure the zinc oxide nanometer structure and the graphen two-dimensional sheet to form a continuous structure in a three-dimensional space; third step: transferring the prepared composite structure onto a substrate to be dried. The method has simple process and low device requirement since the composite structure is synthesized in the solution; the process repeatability is strong, and the process parameter can be well controlled; the prepared graphen / zinc oxide composite structure has large area and is continuous, the generated zinc oxide nanometer sheet layer, nanometer particle and nanometer line are connected with each other and intersected with each other under the effect of the graphen so as to form a continuous porous structure in the three-dimensional space.

The present invention describes methods for preparing high quality nanoparticles, i.e., metal oxide based nanoparticles of uniform size and monodispersity. The nanoparticles advantageously comprise organic alkyl chain capping groups and are stable in air and in nonpolar solvents. The methods of the invention provide a simple and reproducible procedure for forming transition metal oxide nanocrystals, with yields over 80%. The highly crystalline and monodisperse nanocrystals are obtained directly without further size selection; particle size can be easily and fractionally increased by the methods. The resulting nanoparticles can exhibit magnetic and / or optical properties. These properties result from the methods used to prepare them. Also advantageously, the nanoparticles of this invention are well suited for use in a variety of industrial applications, including cosmetic and pharmaceutical formulations and compositions.

An object of the present invention is to provide a metal oxide particle which exercises more excellent ultraviolet absorbency as a matter of course and combines therewith merits of, for example, either being shifted in ultraviolet absorption edge toward the longer wavelength side and being excellent also in the absorption efficiency of a long-wavelength range of ultraviolet rays, or having good transparency and, for example, even in cases where added into or coated onto substrates, not damaging the transparency or hue of the substrates. As a means of achieving this object, a metal oxide particle according to the present invention is a metal oxide particle such that a hetero-element is contained in a particle comprising an oxide of a specific metal element (M), wherein the metal oxide particle is: 1) a metal oxide particle in the form of a fine particle wherein the hetero-element is at least one specific metal element (M′); 2) a metal oxide particle wherein the hetero-element includes at least two specific metal elements (M′); 3) a metal oxide particle wherein: the hetero-element is a more specified metal element (M′) and at least a part thereof is 2 in valence; or the metal element (M) is a more specified metal element and the metal oxide particle is in a specific range in crystal grain diameter in the vertical direction to each of the (002) plane and the (100) plane; or 4) a metal oxide particle wherein: the hetero-element is at least one specific nonmetal element and an acyl group is contained in the particle; or the hetero-element includes at least two specific nonmetal elements; or the hetero-element is at least one specific nonmetal element and a component derived from a metal element (M′) other than the metal element (M) is contained in the particle.

A method for fabricating a Light Emitting Diode (LED) with increased light extraction efficiency, comprising providing a III-Nitride based LED structure comprising a light emitting active layer between a p-type layer and an n-type layer; growing a Zinc Oxide (ZnO) layer epitaxially on the p-type layer by submerging a surface of the p-type layer in a low temperature aqueous solution, wherein the ZnO layer is a transparent current spreading layer; and depositing a p-type contact on the ZnO layer. The increase in efficiency may be more than 93% with very little or no increase in cost.

Nanoparticles comprising zinc, methods of manufacturing nanoparticles comprising zinc, and applications of nanoparticles comprising zinc, such as electrically conducting formulations, reagents for fine chemical synthesis, pigments and catalysts are provided.

The invention provides a multi-shell-layer metal oxide hollow ball and a preparation method thereof. A hydrothermal method is used for preparing a carbon ball template; metal salts are dissolved in carbon ball suspension liquid, and the gradient distribution, the depth and the number of metal salts entering carbon balls are controlled through regulating adsorption conditions such as metal salt concentration, solution pH value, soaking temperature and time and the like; and the heat treatment is carried out on the carbon balls adsorbing metal ions, and the multi-shell-layer metal oxide hollow ball can be obtained. The shell-layer of the hollow ball prepared by the method is formed by accumulating nanometer crystal particles of metal oxides, the shell layer number can be regulated and changed from two to four, and both the size of the hollow ball and the thickness of the shell layers are controllable. The method provided by the invention is simple and is easy to implement, the controllability is high, the pollution is little, the cost is low, and in addition, the general applicability is realized. The prepared product has a hollow structure and the shell layers with the thickness inthe nanometer level, simultaneously, the internal space can be effectively utilized through the multilayer structure, and the multi-shell-layer metal oxide hollow ball is applied to gas sensitivity and photocatalysis and has the more excellent performance through being compared with the traditional nanometer material and a single-layer hollow ball.

A process of treating metal oxide nanoparticles that includes mixing metal oxide nanoparticles, a solvent, and a surface treatment agent that is preferably a silane or siloxane is described. The treated metal oxide nanoparticles are rendered hydrophobic by the surface treatment agent being surface attached thereto, and are preferably dispersed in a hydrophobic aromatic polymer binder of a charge transport layer of a photoreceptor, whereby π—π interactions can be formed between the organic moieties on the surface of the nanoparticles and the aromatic components of the binder polymer to achieve a stable dispersion of the nanoparticles in the polymer that is substantially free of large sized agglomerations.

The invention discloses nano / micron binary structured powders for superhydrophobic, self-cleaning applications. The powders are featured by micron-scale diameter and nano-scale surface roughness. In one embodiment, the average diameter is about 1-25 μm, and the average roughness Ra is about 3-100 nm. The nano / micron binary structured powders may be made of silica, metal oxide, or combinations thereof.

A general, reproducible, and simple synthetic method that employs readily available chemicals permits control of the size, shape, and size distribution of metal oxide nanocrystals. The synthesis entails reacting a metal fatty acid salt, the corresponding fatty acid, and a hydrocarbon solvent, with the reaction product being pyrolyzed to the metal oxide. Nearly monodisperse oxide nanocrystals of Fe3O4, Cr2O3, MnO, Co3O4, NiO, ZnO, SnO2, and In2O3, in a large size range (3-50 nm), are described. Size and shape control of the nanocrystals is achieved by varying the reactivity and concentration of the precursors.

The invention relates to a preparation method for preparing nano-scale oxidized zinc powder with high conductivity. The method simultaneously drip mixed salt solution of zincic soluble salt and doping elements such as aluminum, gallium, indium, Yt, scandium, tin, germanium, silicon, as well as precipitating agent into water, to generate coprecipitation to generate doped zinc bloom precursor basic zinc carbonate in condition of controlling temperature and PH value of entire reaction system, and at last, calcining the product in mixed gas atmospheres of hydrogen gas and argon gas, doped superfine zinc bloom conductive powder material can be obtained. The powder material prepared by the invention has small particle-size, uniform grain fineness distribution, and which mean particle diameter is about 10 to 80 nanometer. The electric volume resistivity of the powder can reach 2.5*10^-3 omega.cm, thus its electro conductivity is better than the sample prepared by plasma method and gas-phase method in current market. The preparation method further enhances whiteness degree and conductivity of the oxidized zinc powder, and further reduces the cost.

The invention provides methods for reduction of metal oxide particles using a high temperature solar aerosol reactor. The invention also provides metal-oxide based processes for the generation of hydrogen from water splitting using a high temperature solar aerosol reactor. In addition, the invention provides solar thermal reactor systems suitable for use with these processes.

Polycrystalline materials of macroscopic size exhibiting Single-Crystal-Like properties are formed from a plurality of Single-Crystal Particles, having Self-Aligning morphologies and optionally ling morphology, bonded together and aligned along at least one, and up to three, crystallographic directions.

The invention discloses a method for synthesizing a zinc oxide nano-tube array by a low-temperature hydrothermal method, which comprises: firstly, preparation of ZnO crystal seed layers; secondly, low-temperature hydrothermal growth of ZnO nano wires; and thirdly, chemical etching of the ZnO nano wires into ZnO nano-tubes. The method adopts the low-temperature hydrothermal method and utilizes pure chemical etching technology to synthesize the ZnO nano-tube array, does not need electrochemical assistance and a template, can prepare the ZnO nano-tubes with controllable pipe diameters on different types of substrates by controlling the concentration of a reactant, the hydrothermal growth time and the etching time of an alkali liquor, has low cost, low reaction temperature, short production cycle and high investment-return rate, can be directly performed in an aqueous solution, and does not generate toxic and harmful waste.

The present invention includes a method of producing a crystalline metal oxide nanostructure. The method comprises providing a metal salt solution and providing a basic solution; placing a porous membrane between the metal salt solution and the basic solution, wherein metal cations of the metal salt solution and hydroxide ions of the basic solution react, thereby producing a crystalline metal oxide nanostructure.

The invention discloses a preparation method of a graphene inorganic nanocomposite, which comprises the following steps: firstly, adding grapheme into the aqueous solution of soluble inorganic salt, and scattering the grapheme by ultrasound; then adding precipitant under the mixing condition, centrifuging at a high speed and heat treating the obtained mixed liquor, and finally obtaining the graphene inorganic nanocomposite. The composite has high surface area, adjustable diameter of nano particles, and important application value on catalysis, stored energy, drug delivery and the like.

Methods are described that have the capability of producing submicron / nanoscale particles, in some embodiments dispersible, at high production rates. In some embodiments, the methods result in the production of particles with an average diameter less than about 75 nanometers that are produced at a rate of at least about 35 grams per hour. In other embodiments, the particles are highly uniform. These methods can be used to form particle collections and / or powder coatings. Powder coatings and corresponding methods are described based on the deposition of highly uniform submicron / nanoscale particles.

The invention relates to platinum-metal oxide composite particles and their use as electrocatalysts in oxygen-reducing cathodes and fuel cells. The invention particularly relates to methods for preventing the oxidation of the platinum electrocatalyst in the cathodes of fuel cells by use of these platinum-metal oxide composite particles. The invention additionally relates to methods for producing electrical energy by supplying such a fuel cell with an oxidant, such as oxygen, and a fuel source, such as hydrogen. The invention also relates to methods of making the metal-metal oxide composites.

A paste is provided having as solid phase at least one nanoscale powder and as liquid phase at least one dispersant, wherein the fraction of the nanoscale powder is 30% to 95% by weight and the fraction of the liquid phase is at least 5% by weight, based in each case on the total amount of the paste, the paste has a water content of less than 3% by weight of water and the liquid phase has a VOC content of less than 10 g / l, and the use of the paste in preparing dispersions, the dispersions prepared thereby, and use in a variety of other enduses.

Nanoparticles comprising titanium, such as nanoscale doped titanium metal compounds, inorganic titanium compounds, and organic titanium compounds, their methods of manufacture, and methods of preparation of products from nanoparticles comprising titanium are provided.

A general, reproducible, and simple synthetic method that employs readily available chemicals permits control of the size, shape, and size distribution of metal oxide nanocrystals. The synthesis entails reacting a metal fatty acid salt, the corresponding fatty acid, and a hydrocarbon solvent, with the reaction product being pyrolyzed to the metal oxide. Nearly monodisperse oxide nanocrystals of Fe3O4, Cr2O3, MnO, Co3O4, NiO, ZnO, SnO2, and In2O3, in a large size range (3-50 nm), are described. Size and shape control of the nanocrystals is achieved by varying the reactivity and concentration of the precursors.

Provided is a single crystal with a hexagonal wurtzite structure which is useful as a substrate for various devices and has high purity and is uniform. The single crystal with a hexagonal wurtzite structures which is obtained by a crystal growth on at least an m-plane of a columnar seed crystal and represented by AX (A representing an electropositive element and X representing an electronegative element) is characterized in that a variation in the concentration of a metal other than the electropositive element A and having a concentration of 0.1 to 50 ppm is within 100%.

Nanoparticles comprising titanium, such as nanoscale doped titanium metal compounds, inorganic titanium compounds, and organic titanium compounds, their methods of manufacture, and methods of preparation of products from nanoparticles comprising titanium are provided.

A low-temperature hydrothermal reaction is provided to generate crystalline perovskite nanotubes such as barium titanate (BaTiO3) and strontium titanate (SrTiO3) that have an outer diameter from about 1 nm to about 500 nm and a length from about 10 nm to about 10 micron. The low-temperature hydrothermal reaction includes the use of a metal oxide nanotube structural template, i.e., precursor. These titanate nanotubes have been characterized by means of X-ray diffraction and transmission electron microscopy, coupled with energy dispersive X-ray analysis and selected area electron diffraction (SAED).

Process for producing nanomaterials such as graphenes, graphene composites, magnesium oxide, magnesium hydroxides and other nanomaterials by high heat vaporization and rapid cooling. In some of the preferred embodiments, the high heat is produced by an oxidation-reduction reaction of carbon dioxide and magnesium as the primary reactants, although additional materials such as reaction catalysts, control agents, or composite materials can be included in the reaction, if desired. The reaction also produces nanomaterials from a variety of other input materials, and by varying the process parameters, the type and morphology of the carbon nanoproducts and other nanoproducts can be controlled. The reaction products include novel nanocrystals of MgO (percilase) and MgAl2O4 (spinels) as well as composites of these nanocrystals with multiple layers of graphene deposited on or intercalated with them.

The invention discloses a preparation method of a super nanostructure material formed by quantum dots self-assembly. That the alcohols are used as solvent to prepare nano-metal oxides and sulphides or metal oxides and sulphides are reduced to get nano-metal is a widely used method. The super nanostructure material formed by the quantum dots self-assembly draws much attention because of the superior comprehensive properties. The application prospect is wide enough. The invention adopts a method of using the alcohols as the solvent that a super nanostructure with different appearances and is formed by the quantum dots self-assembly which is obtained by changing the condition under the existence condition of surfactant. According to the invention, precursor, namely organic metal compound is dissolved in the alcohol solvent by ultrasonic, stirring and being laid down quietly. Under the effect of the surfactant, the precursor has a nucleation and grows into a plurality of quantum dots, the size of which is similar to nano. Then the dots form a super nanostructure which has a certain shape or space structure along the defined growing direction of the surfactant.

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.