1648 results about "Hexagonal boron nitride" patented technology

A method of forming pellets or agglomerates of high density boron nitride from high purity hexagonal boron nitride by crushing the high purity hexagonal boron nitride into boron nitride particles extending over a size range of at least 100 microns with the majority of the particles having a particle size above 50 microns and cold pressing the crushed particles into a compacted form. The compacted form is then granulated into a granulated powder and again cold pressed to form pellets or agglomerates of boron nitride particles with the operations of cold pressing and granulation occurring in one or more stages.

Graphene layers, hexagonal boron nitride layers, as well as other materials made of primarily sp2 bonded atoms and associated methods are disclosed. In one aspect, for example, a method of forming a graphene layer is provided. Such a method may include mixing a carbon source with a horizontally oriented molten solvent, precipitating the carbon source from the molten solvent to form a graphite layer across the molten solvent, and separating the graphite layer into a plurality of graphene layers.

The invention discloses an environmental-protection anti-corrosive heat-dissipation powder paint, and a preparation method and application thereof. The environmental-protection anti-corrosive heat-dissipation powder paint comprises the following raw materials in parts by weight: 40-90 parts of matrix resin, 2-40 parts of curing agent, 0.5-10 parts of carbon nanotube, 0.5-2 parts of additive, 0-4.5 parts of hexagonal boron nitride, 0-15 parts of aluminum nitride, 0-10 parts of magnesium nitride, 0-10 parts of silicon carbide and 5-30 parts of pigment and filler. The composition and proportioning of the raw materials of the powder paint disclosed by the invention are scientific and reasonable. The experimental result indicates that the powder paint has the advantages of favorable heat-dissipation effect, high efficacy enhancement rate (higher than 60%) and favorable cooling effect (more than 20 DEG C), and can effectively solve the problem of poor heat-dissipation effect in the high-power electronic product, thereby prolonging the service life of the electronic product. The powder paint disclosed by the invention is free of organic solvent, and is environment-friendly and safe; the powder paint disclosed by the invention also has favorable comprehensive properties, such as flexibility, hardness, adhesive force and the like, and stable chemical properties; and the coating formed by the powder paint has the advantages of high corrosion resistance and shock resistance, favorable insulation property and wide application range.

Graphene layers made of primarily sp2 bonded atoms and associated methods are disclosed. In one aspect, for example, a method of forming a graphite film can include heating a solid substrate under vacuum to a solubilizing temperature that is less than a melting point of the solid substrate, solubilizing carbon atoms from a graphite source into the heated solid substrate, and cooling the heated solid substrate at a rate sufficient to form a graphite film from the solubilized carbon atoms on at least one surface of the solid substrate. The graphite film is formed to be substantially free of lattice defects.

The present invention relates to a powder comprising boron nitride particles having an aspect ratio of from about 50 to about 300. The present invention also relates to a method of making delaminated boron nitride powder. This method involves providing boron nitride powder and milling the boron nitride powder in a mixture including a milling media and a milling liquid under conditions effective to produce delaminated boron nitride powder.

Graphene layers, hexagonal boron nitride (hBN) layers, as well as other materials made of primarily sp2 bonded atoms and associated methods are disclosed. In one aspect, the present invention provides graphene and hBN devices. In one aspect, for example, an electronic device is provided including a graphene layer and a planar hBN layer operably associated with the graphene layer and forming a functional interface therebetween. Numerous functional interfaces are contemplated, depending on the desired functionality of the device.

This invention relates to a heat spread sheet material comprised of hexagonal boron nitride with adhesives. Extraction process for adhesive coating greatly decreases the adhesive fraction and provides an evenly distributed thin adhesive film on the surface of hexagonal boron nitride powders. This sheet material shows a layer structure and anisotropic properties. With 10 vol % (5.5 wt %) of phenolic epoxy, thermal conductivity along the base plane of the sheet reaches 48 W/m·K, and CTE reaches 3.5 ppm/K.

A new method is disclosed for the exfoliation of hexagonal boron nitride into mono- and few-layered nanosheets (or nanoplatelets, nanomesh, nanoribbons). The method does not necessarily require high temperature or vacuum, but uses commercially available h-BN powders (or those derived from these materials, bulk crystals) and only requires wet chemical processing. The method is facile, cost efficient, and scalable. The resultant exfoliated h-BN is dispersible in an organic solvent or water thus amenable for solution processing for unique microelectronic or composite applications.

An electrical insulation paper that is made of mica flakelets (22), having an average size range of 0.01 to 0.05 mm in their thinnest dimension, hexagonal boron nitride (26), which has an average size range of 10 to 1,000 nm in their longest dimension, and a resin matrix. The mica flakelets and the hexagonal boron nitride are mixed and formed into a paper (17), and the resin is added to the paper after formation, the ratio by weight of the hexagonal boron nitride to the mica flakelets is directly proportional to the average size of the hexagonal boron nitride compared to the average size of the mica flakelets, within an adjustment factor.

The present invention relates to optoelectronic device layer structures, light emitting devices, and detectors based upon heterostructures formed between hexagonal boron nitride (hNB) and III-nitrides, and more particularly, to heterojunction devices capable of emitting and detecting photons in the ultraviolet (UV) and extremely ultraviolet (RUV) spectral range. The present invention also relates to neutron detectors based on epitaxially grown hBN thin films (or epitaxial layers) and hBN stacked thin films (or epitaxial layers) to satisfy the thickness required for capturing all incoming neutrons.

The invention relates to boron nitride agglomerates, comprising lamellar, hexagonal boron nitride primary particles, which are agglomerated with one another with a preferred orientation, the agglomerates formed being flake-shaped.

The invention also relates to a method for producing said boron nitride agglomerates, characterized in that lamellar, hexagonal boron nitride primary particles are agglomerated in such a way that they line up with one another with a preferred orientation.

The flake-shaped agglomerates according to the invention are suitable as filler for polymers for making polymer-boron nitride composites and for hot pressing of boron nitride sintered compacts.

The invention relates to a method for modifying a boron nitride nanosheet with polydopamine. The invention aims to provide a method of using a mixed solvent of a polar organic solvent and water to conduct ultrasonic stripping of hexagonal boron nitride and modifying a boron nitride nanosheet surface with polydopamine. The boron nitride nanosheet obtained by the method provided by the invention has the characteristics of good dispersibility in the mixed solvent of the polar organic solvent and water, high yield and long storage time. The polydopamine surface modified boron nitride nanosheet prepared by the method has easy storage properties and good dispersibility in a solvent. The method for modifying a boron nitride nanosheet with polydopamine provided by the invention has the advantages of simple operation, safety and low cost, etc.

The invention discloses a functionalized boron nitride nanosheet and a preparation method and application thereof. The preparation method of the functionalized boron nitride nanosheet mainly comprises the following steps: (1) uniformly mixing boron nitride powder with a hydroxyl-containing organic solid; (2) continuously or discontinuously applying a mechanical acting force to the mixture; (3) removing residual organic solid in the mixture by means of water or an organic solvent to obtain wet functionalized boron nitride, and further drying and grinding the wet functionalized boron nitride to obtain dry functionalized boron nitride; (4) dispersing the wet or dry functionalized boron nitride in a solvent, leaving the mixture to stand or centrifugalizing the mixture, and taking supernate; and (5) filtering or centrifugalizing the supernate at a high speed and collecting the solid matter to dry to obtain the functionalized boron nitride nanosheet. The preparation method disclosed by the invention has the advantages of being simple to operate, high in yield, low in cost and the like, and the obtained functionalized boron nitride nanosheet is good in dispersibility in water, organic solvents and resin matrixes, and convenient for scaled production and application.

The invention relates to a doped hexagonal boron nitride nano sheet, a preparation method thereof, a catalyst using the same as the carrier, and applications thereof. The preparation method comprises the following steps: adding a single substance or compound of hetero atoms, a single substance or compound of boron, and a nitrogen compound into water, evenly mixing, drying to remove water; then grinding the solid, placing the powder in a tubular furnace, introducing inert gas into the tubular furnace, heating the tubular furnace to a temperature of 800 to 1200 DEG C by program to carry out reactions, after reactions, cooling to the room temperature; grinding the reaction products, then boiling the grinded products in hot water, filtering when the water is still hot, washing the filter residue by hot water and ethanol, and drying. The doped hexagonal boron nitride nano sheet is taken as the carrier to prepare a catalyst, the active components loaded on the carrier can be one or more of transition metals, and the catalyst is used to catalyze organic reactions. A high temperature pyrolysis method is adopted, and the controllable preparation of nano material is achieved through controlling the ratio of each element in raw materials. The method is simple, the operation is easy, and the yield is high. The doped hexagonal boron nitride nano sheet can be used as the catalyst carrier, and is capable of improving the dispersity and catalytic activity of metal nano particles.

A boron nitride nanosheet containing three-layered hexagonal boron nitride, which is in a form of multi-layered hexagonal boron nitride with some its layers peeled, can be produced by dispersing pristine hexagonal boron nitride powder in an organic solvent and by subjecting the fluid dispersion to ultrasonication.

The invention discloses a micro-embedded self-lubricating texture on the surfaces of a gear and a cam and a preparation method thereof. The preparation method comprises the following steps of: performing micro texture processing on the surfaces of the gear and the cam by an Nd: YAG laser processing technology; and embedding a solid lubricant into the micro texture on the surfaces of the gear and the cam by a molding bonding technology of a self-lubricating composite material. The self-lubricating composite material comprises the following formula components in percentage by mass: 15 to 85 percent of polyimide (PI), 0 to 85 percent of polytetrafluoroethylene (PTFE), 10 to 40 percent of MoS2, 0 to 15 percent of WS2, 0 to 16 percent of graphite fluoride, 5 to 15 percent of graphite, 0 to 12 percent of PbO, 0 to 6 percent of antimony trioxide, 0 to 10 percent of CaF2 or BaF2, 0 to 15 percent of hexagonal boron nitride, 0 to 15 percent of nano lubricant and 0 to 5 percent of additive. According to the micro-embedded self-lubricating texture, the self-lubricating texture is subjected to micro embedding on the surfaces of the gear and the cam to ensure that the solid lubricant on the friction surface is stably supplied and uniformly coated, so that the lubrication and anti-wear properties of friction pairs such as the gear and the cam under complicated and harsh operating conditions are improved.

Compositions and methods for ballistic conditioning firearm projectiles, firearms, and firearm components such as bores of barrels, by applying to such items a conditioning composition selected from the group consisting of hexagonal boron nitride, graphite, tungsten disulfide, antimony trioxide, talc, mica, and mixtures thereof, suspended in a carrier comprising a volatile solvent, and a binder selected from the group consisting of cellulosic-, alkyd- and acrylic-resins.

The invention relates to a preparation method of a cubic boron nitride and diamond polycrystal with a nanometer structure. The preparation method comprises the steps: with hexagonal boron nitride and diamond mixed powder or cubic boron nitride and diamond mixed powder as the raw material, purifying for removing impurities in the raw material, then, assembling a sintering unit without adding any binder, and directly sintering at high temperature and superhigh pressure to prepare the cubic boron nitride and diamond polycrystal with the nanometer structure, wherein diamond accounts for 10-90% of the mass percentage of the raw material. The cubic boron nitride and diamond polycrystal with the nanometer structure is uniform in phase distribution, cubic boron nitride crystal grains have nanometer sizes, and diamond crystal grains are uniformly distributed in the nano cubic boron nitride crystal grains, thus a nanometer cubic boron nitride and diamond interface which is compact in combination and high in strength is formed at a large area. Therefore, the hardness of the high-performance cubic boron nitride and diamond polycrystal with the nanometer structure is equal to that of a diamond monocrystal, and the thermal stability, hardness and wear resistance of the high-performance cubic boron nitride and diamond polycrystal with the nanometer structure are also remarkably higher than those of a diamond polycrystal containing a metal binder.

An object of the present invention is to industrially easily mold a molded article which is excellent in thermal conductivity, electric insulation property, low density, and an injection moldability and has a thermal conduction anisotropy. The present invention relates to a highly thermally conductive resin molded article having a thermal diffusion anisotropy, the highly thermally conductive resin molded article comprising a resin composition, the resin composition containing at least resin (A) and plate-like hexagonal boron nitride powder (B) in a (A)/(B) volume ratio falling within a range of 90/10 to 30/70, the resin (A) including a thermoplastic polyester resin and/or a thermoplastic polyamide resin, the highly thermally conductive resin molded article having a thickness of not more than 1.3 mm in a part of or all over a three-dimensional shape of the highly thermally conductive resin molded article, a thermal diffusivity measured in a plane direction of the highly thermally conductive resin molded article, being (i) two or more times higher than a thermal diffusivity measured in a thickness direction of the highly thermally conductive resin molded article and (ii) not less than 0.5 mm²/sec.