35results about How to "Control nitrogen content" patented technology

The invention discloses a method for preparing a nitrogen-doped graphene material with a hydrothermal process, relating to a method for preparing the nitrogen-doped graphene material. The technical problems of lower nitrogen content, difficulty in control of nitrogen content, high production cost, complex structure of equipment required by reaction, rigorous reaction conditions, low yield, difficulty in industrialized production and the like in the traditional method for preparing the nitrogen-doped graphene material are solved in the invention. The method comprises the steps of: 1, dissolving graphite oxide in a solvent, adding a surfactant and uniformly mixing; 2, adding a nitrogen-containing compound, and uniformly mixing; and 3, after a hydro-thermal reaction, washing and drying to obtain the nitrogen-doped graphene material. The nitrogen-doped graphene material prepared in the invention has the advantages of higher nitrogen content, controllable nitrogen content, low production cost, simple structure of required equipment, high yield and easiness in realizing industrialized production.

The invention relates to a viscosity index improver for a hydrogenated styrene-diene copolymer and a preparation method thereof. The copolymer is a hydrogenated star polymer; and at least 95% of the unsaturated double bonds of diolefin are hydrogenated, and at most 10% of the unsaturated bonds of aromatic hydrocarbon are hydrogenated. The polymer has the following characteristics before hydrogenation: the core of the polymer is a poly(divinylbenzene) residue; the arms of the polymer are two-block copolymers, and a block I is an isoprene-butadiene copolymer while a block II is polystyrene; the number of the arms is 3; single-arm molecular weight is 20, 000 to 100, 000; and the contents of polystyrene, polyisoprene and polybutadiene by mass are 2 to 15%, 30 to 90% and 5 to 60%, respectively. The improver has excellent thickening capability, shearing stability and soot dispersibility.

The invention discloses a preparation method of a novel three-dimensional nitrogen doped graphene composite material system. The method comprises the following steps: 1, uniformly dispersing graphene oxide in a solvent at room temperature, adding a selected material and a nitrogen-containing compound, and uniformly mixing to form a mixed solution; 2, reacting the mixed solution at a temperature from room temperature to 150DEG C for 0-8h; and 3, cooling the above obtained product to room temperature, centrifuging, collecting the obtained product, washing, and drying to obtain the nitrogen doped graphene composite material. The three-dimensional nitrogen doped graphene composite material system with the nitrogen content of 8-19% can be efficiently and controllably prepared through the method, and the nitrogen content of the system can be controlled by changing the kind and the amount of the added nitrogen-containing compound, the reaction temperature and the reaction time; and the method is simple, is easy to enforce, allows the yield to be greater than 98.9%, and can be widely used in fields of water treatment, biomedicines, energy generation, conversion and storage devices, electrostatic prevention, heat management, heat conduction and dissipation, sensors, electromagnetic shielding, wave absorption and catalysis.

The invention provides a large area nitrogen-doped carbon nano-tube paper preparation method, which comprises: (1) weighing ferrocene powder, dissolving in dichlorobenzene to form a ferrocene / dichlorobenzene carbon source solution, weighing pyridine, and mixing the pyridine and the ferrocene / dichlorobenzene carbon source solution to form a ferrocene / dichlorobenzene / pyridine mixing carbon source solution; 2) coiling an iron sheet or copper sheet substrate into a cylindrical material, placing into the quartz reaction chamber of a reaction furnace, sealing the reaction chamber, introducing argon gas to completely discharge air, and heating the reaction furnace; 3) when the temperature of the reaction chamber achieves 750-900 DEG C, adjusting the argon flow rate while introducing hydrogen; 4) injecting the ferrocene / dichlorobenzene / pyridine mixing carbon source solution into the reaction chamber, and carrying out a reaction; and 5) stopping the heating of the tubular reaction furnace, closing the hydrogen, adjusting argon flow rate to make the product be cooled to a room temperature along with the furnace, and collecting the large area nitrogen-doped carbon nano-tube paper on the substrate. According to the present invention, the nitrogen-doped structure carbon nano-tube film two-dimensional structure and the simple, rapid and large-scale preparation method can be used for the fields of new energy sources, sensors, flexible electronic devices, and the like.

The invention provides a negative electrode material for a lithium ion battery. The negative electrode material has a silicon nitride structure mainly composed of β-phase silicon nitride, and the silicon nitride contains more than 50 wt% of the β-phase silicon nitride. The β-phase silicon nitride has a layered hexagonal crystal structure. Because of its layered characteristics, it facilitates the insertion and extraction of lithium ions, reduces the lithium dendrite (Lithium Dendrites) structure due to the inability to insert lithium ions smoothly, and Due to the stable structure and size during charging and discharging, it can greatly reduce the decline in capacitance caused by material breakage and disintegration, so as to improve the cycle life. The β-phase silicon nitride disclosed in the present invention has a chemical formula of β-Si3Nx, where 1≦x≦4, and due to the low nitrogen atomic weight percentage, the β-phase silicon nitride (β-Si3Nx) has unstable dangling bonds , unsaturated bonds and other unpaired bonds can improve the activity and capacitance of negative electrode materials.

The invention relates to N-TiO2 / C and N-TiO2 and a preparation method thereof, and specifically discloses a method for preparing nitrogen-doped titanium oxide and its nanocomposite with carbon by heat treatment in air. Its preparation method includes the following steps: (1) Mix 10wt% tetramethylammonium hydroxide aqueous solution with ethylene glycol, add titanium isopropoxide, stir well, and heat the obtained solution at 200°C for 8 hours; (2) Mix the step ( 1) The obtained hydrothermal product is centrifuged and washed in ethanol and deionized water, and dried in air at 70°C; (3) The dried product in step (2) is heat-treated in air at 250-550°C for 2 hours, that is A nitrogen-doped titanium oxide / carbon nanocomposite or nitrogen-doped titanium oxide is obtained. The nitrogen-doped titanium oxide / carbon nanocomposite and the nitrogen-doped titanium oxide obtained by the invention have the advantages of high nitrogen content, extended absorption spectrum to the light region, visible light photocatalytic activity and the like. The adopted preparation method has the advantages of simplicity, high safety factor, low cost and the like.

The invention relates to a method for controlling the nitrogen content in N80 steel. The method comprises the following steps: firstly, the LF slag smelting is stabilized and the deoxidation technology is perfected so that the weight and the components of the molten slag are controllable and the nitrogen flushing state during the process is stable; secondly, the proper nitrogen flushing flow, pressure and time are set in the VD packing process so that the nitrogen content after emptying is stable; and thirdly, the proper nitrogen flushing time, flow and pressure are set after the VD emptying so that the nitrogen content is stable and controllable. The method performs improvement to the non-quenching and tempering way, effectively controls the nitrogen content in the N80 level steel by taking measures, not only has low cost, but also effectively reduces the surface cracks of the casting billet and improves the quality of products.

The invention discloses a steelmaking production method of 600MPa peritectic high-alumina TRIP steel. The steelmaking production method comprises the steps of molten iron desulfurization, converter smelting, LF refining, RH treatment and medium slab continuous casting. The invention produces continuous casting slabs that meet the requirements by applying the rapid tapping process of the converter, the LF rapid slagging process, the RH degassing process, and the continuous casting slab control process. The production process is stable and can effectively control the full oxygen and Nitrogen content, O≤5ppm, N≤30ppm, the quality control of the steelmaking slab is good, the segregation grade of the slab is below C class 1.5, and the surface of the slab has no cracks; the slab can be used for hot rolling to produce high-quality hot-rolled coils , cold-rolled to produce high-quality cold-rolled products.

The invention belongs to the technical field of ferrous metallurgy, and particularly relates to a method for adding nitrogen to ultra-low carbon enamel molten steel. The method comprises the following steps: decarbonizing by utilizing nitrogen as a lift gas while controlling the flow of the lift gas at 150-170Nm<3> / h, and exhausting, so that the vacuum degree of a decarburization furnace is not greater than 100Pa; gradually lifting the flow of the lift gas to 210-230Nm<3> / h, and finishing the decarburization stage until the carbon content in the molten steel is not greater than 20ppm, wherein the vacuum degree of the decarburization furnace is not greater than 1kPa; carrying out a deoxidation operation; adding alloy and controlling the flow of the lift gas in an interval corresponding to 160-180Nm<3> / h or 200-220Nm<3> / h; breaking vacuum until the molten steel accords with the ultra-low carbon enamel molten steel ingredient. Nitrogen is added in decarburization by controlling the flow of the lift gas of nitrogen, the vacuum degree and the decarburization time of the decarburization furnace in the decarburization and deoxidation processes, so that the nitrogen content of a finished product can be accurately controlled, use of alloy is reduced, and the cost is reduced.

The invention relates to a three-dimensional graphene composite material with a core-shell structure for a capacitive desalination electrode and a preparation method thereof. The method uses metal-organic framework as the core and graphene as the shell; through the electrostatic interaction between a certain concentration of graphite oxide solution and the metal-organic framework at a certain temperature, the precursor of the three-dimensional composite material with a core-shell structure is formed; further carbonization, pickling A three-dimensional graphene composite material is obtained; the composite material, acetylene black and polytetrafluoroethylene emulsion are evenly mixed, coated on graphite paper, and dried to obtain a capacitive desalination electrode. The process of the invention is fast, simple, low in cost and can be produced in batches. The obtained electrode has high specific surface area, good conductivity and wettability, and has potential application prospects in capacitive desalination.

The invention relates to a method for remelting high-strength stainless steel. The method is characterized by including the steps that Fe-Mn-Cr nitrogen absorption alloy melt containing manganese and chromium is first smelted, then, high-nitrogen steel waste material is added to the nitrogen absorption alloy melt step by step at low melt temperature, nitrogen-containing alloy is added in proportion according to the designed composition proportion of high-nitrogen steel, and after being completely melted and homogenized, the nitrogen-containing alloy is discharged for pouring. The method solves the problem that the nitrogen content is insufficient in the recovering and remelting processes of the high-nitrogen steel waste material and can control the nitrogen content of new high-nitrogen steel smelted by the high-nitrogen steel waste material to be close to or not lower than that of the original high-nitrogen steel waste material.