49 results about "Boron carbonitride" patented technology

The invention belongs to the technical field of nanometer material preparation, and relates to a three-dimensional porous boron carbonitride material, as well as a preparation method and application thereof in the field of photocatalysis. The method comprises the following steps: by adopting boric acid, urea and starch as raw materials, mixing with sodium chloride salt, adding an appropriate amount of water, carrying out ultrasonic processing for dissolving, uniformly mixing, standing under normal pressure and temperature, self-forming a precursor with a three-dimensional porous structure after several hours, carrying out high temperature heat polymerization under an ammonia atmosphere, and synthesizing to obtain the three-dimensional porous boron carbonitride material. The preparation method provided by the invention has the advantages of simple process, cheap materials, and mild and controllable conditions. The obtained boron carbonitride material is remarkably increased in specificsurface area, smaller in pore diameter, remarkably improved in charge separation, and favorable in photocatalytic performance, and has wide application in the fields such as photoelectricity, catalysis, organic pollutant photodegradation and adsorption, and energy storage.

The controllable hydrothermal constant-pressure synthesis method for boron carbonitride material comprises: treating the deionized water, preparing liquids for boron resource, carbon source and nitrogen source respectively; putting into the kettle; forcing 20~2000MPa pressure then heating the kettle to 240~1000Deg with 0.01~60Deg / min speed for reaction 6~480h. Wherein, it can adjust and control the system temperature and pressure independently as well as the reaction speed and direction. All the product of diamond, cubic boron nitride and carbonitride crystal block have wide application.

The invention discloses a boron carbon nitrogen nano paper and a preparation method thereof. The boron carbon nitrogen nano paper is composed of boron carbon nitrogen nano fibers interwoven into a network structure, and its chemical composition is BxC5Ny, where x=0.1~ 3.0, y=0.1~2.5. The preparation method includes (1) preparing a precursor solution; (2) preparing a spinning solution; (3) electrospinning the spinning solution to obtain boron carbon nitrogen nano fibrils; (4) preparing boron carbon nitrogen nano fibrils Form boron-carbon-nitrogen nano-crosslinked fibers; (5) Warm up boron-carbon-nitrogen nano-crosslinked fibers to 350°C-500°C under nitrogen protection, and then heat up to 800°C in ammonia / nitrogen mixed atmosphere or ammonia atmosphere ~1000°C, boron carbon nitrogen nano paper is obtained. The composition of the boron carbon nitrogen nanometer paper is adjustable, easy to operate, simple in preparation method, low in cost, and adjustable in chemical composition of the product.

The invention discloses a method for preparing a reinforced polycrystalline cubic boron nitride composite superhard material. Such as cubic carbon boron nitride c-BC2N, boron carbide (B4C) and nano-twinned cubic boron nitride are added to the PCBN material. The reinforcing phase of superhard materials such as (nt-CBN) is a new method of high temperature and high pressure sintering to synthesize superhard composite materials, which belongs to the field of superhard materials. The steps are: cutting a material with extremely high hardness into reinforced core cylinders, embedding the reinforced core cylinders in the powder, putting pyrophyllite blocks into them, and synthesizing under high temperature and high pressure conditions to obtain PCBN materials with reinforced cores. The strengthened PCBN composite superhard material prepared by the present invention has both the toughness of PCBN and the ultrahigh hardness comparable to natural diamond materials, which solves the increasingly higher requirements of the modern machining industry for cutting tools and the application of some extremely superhard materials. The embarrassing situation in this field has broadened the application field of superhard materials.

The invention discloses a method for preparing a carbon / carbon-boron nitride friction-reducing composite material. The graphitized C / C green body is acidified, washed to neutral to obtain a pretreated C / C green body, and then soaked In a solution containing a modifier, react to obtain a functionalized C / C green body, and then immerse the functionalized C / C green body in the h-BN slurry, and dry to obtain a C / C-BN prefabricated body, C / C-BN prefabricated body is carbonized and densified by carbon source, and graphitized to obtain C / C-BN antifriction composite material; the modifier is selected from silane coupling agent or polyvinyl alcohol (PVA) . The invention adopts the slurry impregnation method firstly to obtain the BN matrix. After functionalizing the C / C body, the BN powder can be effectively introduced into the C / C body during the slurry impregnation process. This method can effectively avoid the damage of carbon fibers and ensure the excellent structural strength of C / C‑BN composites. The obtained C / C‑BN composites have excellent friction and wear properties.

The invention discloses a preparation method of a C / C-SiC composite material containing a carbon-rich boron nitride interface phase. The method is as follows: 1) Add AM and MBAM to the precursor solution A containing boric acid and urea to mix and dissolve, then add the initiator ammonium persulfate APS to initiate the polymerization reaction to form sol solution B; 2) immerse the carbon fiber preform in the sol solution In B, dry after impregnation, repeat impregnation, drying, and heat treatment to obtain a carbon fiber prefabricated part containing a carbon-rich boron nitride interface phase; layers of C / C‑SiC composites. The interfacial phase in the prepared material, on the one hand, can prevent liquid silicon from corroding fibers because there is no chemical reaction between BN and liquid silicon; Carbon can improve the wettability of the interface to silicon, thereby increasing the bonding strength between the interface and the matrix. The coupling of the two effects ultimately greatly improves the mechanical properties of the C / C‑SiC material.

The invention relates to a preparation method of an ordered mesoporous silicon-boron-carbon-nitrogen material. The preparation method comprises the following steps: under the protection of nitrogen gas, dripping butyldichloroborane and dichloromethylsilane solutions into a hexamethyldisilazane solution at the same time; then raising the temperature and stirring to obtain a clarified transparent solution; raising the temperature of an oil bath and reacting to obtain a polyborosilazane precursor solid; dissolving the polyborosilazane precursor solid into a solvent and evaporating the oil bath to obtain a self-assembled polyborosilazane precursor; carrying out heat treatment to obtain a cross-linked self-assembled polyborosilazane precursor; under an ammonia gas atmosphere, raising the temperature and carrying out cracking; then cooling to room temperature, so as to obtain the ordered mesoporous silicon-boron-carbon-nitrogen material. The ordered mesoporous silicon-boron-carbon-nitrogen material prepared by the preparation method provided by the invention has large specific surface area and extremely excellent high-temperature stability, oxidation resistance, hydrothermal stability and chemical stability.