41results about How to "Good degree of graphitization" patented technology

The invention discloses a carbon micro-tube epoxy resin wave-absorbing composite material and a preparation method thereof, and relates to a wave-absorbing composite material and a preparation method thereof. The invention solves the problems that the existing active carbon fiber epoxy resin composite wave-absorbing material has fussy preparation process and large density, the hollow fiber prepared by a spinning method has low elastic modulus and the wave-absorbing material has poor strength. The composite material is prepared from carbon micro-tube and epoxy resin glue. The method comprises the following steps of: preparing the carbon micro-tube by using urea and ethylene glycol; preparing the epoxy resin glue by using bisphenol A epoxy resin, acetone and diethylenetriamine; and adding the carbon micro-tube into the epoxy resin glue, stirring the mixture uniformly, then adding the mixture into a die, and pressing the mixture to obtain the composite material. The elastic modulus of the material is 10 to 20GPa, the density is 1.00 to 1.05g / cm<3>, the lowest reflectivity is -13.25dB, the band width of -10dB reflectivity is 3.1GHz, and the material can be used for hiding weapons and eliminating the harm of electromagnetic wave to the organism.

The invention belongs to the field of electrochemistry catalysis, and discloses a preparation method of an atomic dispersion non-noble metal fuel battery cathode catalyst. The method comprises the following steps: (a) heating and dissolving alginate into an alginate solution, keeping a heating temperature, adding metal salts into the alginate solution, and generating an alginate chelate solution; (b) adding organic nitride into the alginate chelate solution, enabling the organic nitride and the alginate chelate solution to react, and drying a product after reaction by steaming to obtain a powdered compound; and (c) successively performing primary heat treatment, acid pickling and secondary heat treatment on the powdered compound, thus obtaining the needed catalyst. By virtue of the preparation method, the catalyst with high activity in an acid medium is prepared, and active sites are uniformly dispersed and fixed, so that the preparation method is easy in control and regulation and suitable for large-scale production and application.

The invention discloses a hollow carbon fiber felt epoxy resin composite material and a preparation method thereof, relates to a carbon fiber epoxy resin composite material and the preparation method thereof, and aims to solve the problems of high density of a conventional carbon fiber epoxy resin composite material and difficult three-dimensional weaving of the carbon fiber serving as a composite material reinforcement. The hollow carbon fiber felt epoxy resin composite material is prepared from a hollow carbon fiber felt and epoxy resin adhesive; and the method comprises the following steps of: placing urea and carbon powder in a graphite crucible; preparing the hollow carbon fiber felt in an atmosphere sintering furnace; placing the hollow carbon fiber felt in a mould; sealing the mould and pouring the epoxy resin adhesive consisting of bisphenol A epoxy resin, acetone and diethylenetriamine into the mould under vacuum; and pressing the mould and drying the mould under vacuum to obtain the hollow carbon fiber felt epoxy resin composite material. The hollow carbon fiber felt is self-woven and the density of the composite material is only 0.92 to 0.94g / cm<3>, so the material can be used for spacecrafts, artificial satellites, space shuttles and missiles.

The invention relates to a controllable synthesis method for a nitrogen and phosphorus co-doped graphitized carbon ball with a hollow structure. The method comprises the following preparation steps: (1) a carbon source, soluble metal salt and a catalyst are dissolved in a solvent according to a molar ratio, the mixture is transferred to a hydrothermal reaction kettle for hydrothermal synthesis after stirred to be dissolved completely, and an obtained precipitate is cleaned, filtered and dried to obtain a primary product; (2) the obtained primary product is subjected to high-temperature reduction under the protection of gas in a high-temperature reaction furnace; and (3) the product obtained by high-temperature reduction is placed in an acid solution to be soaked, and then cleaned, filtered and dried to obtain the nitrogen and phosphorus co-doped graphitized carbon ball with the hollow structure. The nitrogen and phosphorus co-doped graphitized carbon ball with the hollow structure prepared with the method has the advantages that the appearance is uniform, a carbon shell has a cellular structure, the interior of the carbon ball has a mesoporous carbon support structure, the graphitization degree is good, and the like; and the carbon ball can be used in various fields of efficient catalytic conversion, energy storage and conversion, medicine release and control, substance adsorption and separation and the like. A template-free hydrothermal synthesis technique is simple and controllable, and can be used for mass production.

The present invention relates to a metal oxide catalyst and a method for preparing bundled multiwall nano carbon tube by using said metal oxide catalyst and catalytic cracking methane, said metal oxide catalyst is the Fe / Mo / MgO and Ni / Mo / MgO catalyst formed from oxide of magnesium and molybdenum as main catalyst and iron or nickel as auxiliary catalyst. Said catalyst is placed in the fixed bed gas continuously-flowing reaction furnace, and the methane whose introduced flow rate is 50-1500 sccm and the hydrogen gas or nitrogen gas or inert gas whose flow rate is 50-300 sccm are reacted for 10-100 min. at 750-1200 deg.C so as to form the invented bundled multiwall nano carbon tube.

The invention discloses a method for producing hollow carbon fibers, which relates to a method for producing carbon fibers. The invention solves the following problems of the prior spinning production process for producing hollow carbon fibers: high temperature, low elasticity modulus, impurities contained in hollow carbon fibers produced by the chemical vapor growing method and difficult synthesization of hollow carbon fibers with the caliber of hundreds of nanometers to a few microns. The method includes the following steps: (1) carbon source material is put into a graphite crucible, the graphite crucible is put into an atmosphere sintering furnace, and the atmosphere sintering furnace is vacuumized to 0.1Pa to 1Pa; (2) high-pure nitrogen or argon is filled into the furnace until pressure reaches 0.2MPa to 2.5MPa; (3) the temperature is increased to 900 DEG C to 1500 DEG C at 5 DEG C / min to 30 DEG C / min, and is then kept for one to four hours, and the furnace is then cooled to the room temperature, so that hollow carbon fibers are obtained. The reaction temperature of the method is low, catalyst is not used, the graphitization degree of the synthesized hollow carbon fibers is high, the hollow carbon fibers do not contain impurities, and the purity is 100 percent. The hollow carbon fibers are applicable to capacitors, hydrogen storage and composite materials.

The invention discloses a method and a product for preparing an oxygen reduction catalyst from biomass, which comprises the following steps: S1 mixing and freeze-drying the biomass and a transition metal salt solution to obtain a mixture; S2 pyrolyzing the mixture under an inert atmosphere Obtain a core-shell structure material with graphite carbon layer wrapped transition metal nanoparticles; S3 disperse the core-shell structure material in a volatile organic solvent, add nitrogen-containing organic matter and transition metal salt solution 2, mix and dry to obtain mixture 2 ; S4 Pyrolyzing the mixture two under an inert atmosphere to grow nitrogen-containing carbon nanofibers on the surface of the core-shell structure material, and obtain the required oxygen reduction catalyst after washing, filtering and drying. The invention can prepare the sea urchin-shaped oxygen reduction catalyst, has developed porosity, high nitrogen content, stable metal active sites, and has good activity and durability in oxygen reduction catalysis.

The invention discloses an arc plasma torch preparing nanometer charcoal fibrous material method, which comprises the following steps: placing untreated leavings of liquefying coal directly in direct current arc plasma torch to carry on heat-treatment; using nitrogen for arc working gas under atmosphere pressure; getting nanometer charcoal fibrous material after 120-175 seconds, wherein there is no need to add in any activators in preparing process. The method is characterized by the following: the craft route is simple; the raw material is the waste of coal hydrogenant liquefaction craft; it's a good way to use coal liquification leavings to prepare high-added value, functional carbon material; the nanometer charcoal fibrous material can be used for accelerating agent, catalyst carrier, lithium ion secondary cell anode material, double-layer capacitor electrode, highly effective active solid, release agent and construction reinforced materials.

The invention discloses a refractory castable containing in-situ carbon, which comprises A component and B component, and the A component is composed of refractory raw material corundum particles, sintered magnesia, activated alumina micropowder, calcium aluminate cement and silica micropowder , B component is transition metal in-situ doped polymer solution. The present invention adds transition metal in-situ doping polymer aqueous solution to the raw material, on the one hand endows the refractory castable raw material mixture with fluidity during the preparation process; on the other hand, during the sintering process, the polymer is pyrolyzed to generate carbon materials, Realize the dispersion of carbon materials in castables, and at the same time transition metals improve the degree of graphitization of carbon materials generated in situ. According to the theory of in situ synthesis, carbon materials in refractory castables containing in situ carbon have good dispersion and can play The slag non-wetting properties of the material endow carbon-containing refractory castables with superior mechanical properties and corrosion resistance. The invention also provides a method for preparing refractory castables containing in-situ carbon, which has a simple process and is beneficial to industrial production.

The invention provides the preparation and application of a glucose-based porous carbon material. The method comprises the following steps: dissolving glucose in deionized water and stirring to obtain solution A; dissolving iron powder and trimesic acid in deionized water, and Add hydrofluoric acid and nitric acid dropwise, stir to obtain solution B; add solution A to solution B, stir evenly, transfer the resulting mixed solution into a stainless steel high-pressure reactor, and then heat to react; the reaction product is centrifugally washed with water, soaked in ethanol and vacuum-dried; The dried product is mixed with an activator, and then activated by heating to obtain an activated product; the activated product is sequentially subjected to pickling, water washing and vacuum drying to obtain a glucose-based porous carbon material. The glucose-based porous carbon material prepared by this method has high specific surface area, rich hierarchical pore structure and good VOCs adsorption performance.