43results about How to "Single layer rate is high" patented technology

The invention provides a preparing method of graphene oxide. The preparing method includes the following steps that concentrated sulfuric acid, graphite and fuming nitric acid are mixed for reaction, the product is cooled, potassium permanganate is added and mixed for reaction, then water is added to quench the reaction, and finally hydrogen peroxide is added to obtain graphene oxide. Compared with the prior art, fuming nitric acid is used as intercalator, and obtained graphene oxide is high in monolayer rate.

The invention provides a preparation method of an oxidized graphene doped hollow fiber nanofiltration membrane. The preparation method comprises the steps that a plurality of hollow fiber nanofiltration membrane serve as basic membranes to be packaged into a component shell to obtain a membrane component for usage; oxidized graphene, an active monomer and an acid absorbing agent are added into a solvent A for uniform ultrasonic mixing to obtain a solution A; multielementacyl chloride is dissolved in a solvent B to obtain a solution B; the solution A is introduced into the inner cavity of the hollow fiber nanofiltration membrane of the membrane component for full infiltration, the solution A is removed, drying is performed, the solvent B is introduced into the inner cavity of the membrane for interfacial polymerization reaction, then the solution B is removed, drying is performed, andpure-water rinsing and drying are performed to obtain the membrane. The oxidized graphene is added in the membrane preparation process and has the very good effect on the aspects of surface hydrophilicity improvement, membrane flux increase and pollution resistance. The product is good in mechanical strength andcontamination resistance and is higher than an oxidized-graphene-free pure polyamide nanofiltration membraneindesalting rate and water flux.

The invention belongs to the field of material preparation, and relates to a preparation method for preparing a graphene dispersion liquid by electrochemical swelling. The method comprises the following steps: (1) taking graphite sheets as a cathode and taking a graphite substrate as a cathode to carry out electrolysis on the electrodes in an electrolytic tank, wherein the electrolyte is an acetonitrile solution dissolved with a quaternary ammonium salt, and the concentration of the quaternary ammonium salt is 5-10 mg/mL; (2) rinsing the cathode by using a rinsing solution containing a dispersing agent, carrying out ultrasonic stripping on the solution subjected to rinsing to form a dispersion, then centrifuging the dispersion, washing the dispersion by using isopropyl alcohol to remove the excess dispersing agent; and (3) separating solid impurities to obtain the graphene dispersion liquid. According to the method, the graphene nanosheets are swelled and dispersed through an electrochemical method, quaternary ammonium salt cations are inserted into interlayers of the graphene, and then interlayer expansion is achieved, and preparation efficiency of the graphene dispersion liquid is improved.

The invention provides a method for large-scale, continuous and efficient graphite oxide stripping. The method comprises the following steps that purified and diluted graphite oxide dispersion liquid is delivered to a high-speed shear device, a high-speed water flow produced in the process of a high-speed mechanical shear method bumps and impacts graphite oxide to perform rapid macroscopic dispersion and partial stripping of graphite oxide; the graphite oxide dispersion liquid is introduced to a continuous ultrasonic device, the partially stripped graphite oxide having good macroscopic dispersion is rapidly stripped to obtain a single layer by virtue of a high-pressure and high-speed microjet produced by the ultrasonic cavitation effect in the process of an ultrasonic stripping method, and the microcosmic, uniformly dispersed and stable graphite oxide dispersion liquid is obtained. The method strengthens dispersion and stripping of the graphite oxide through a coupling shear field and an ultrasonic field, the obtained graphene oxide is high in single-layer rate, high in concentration and controllable in size, has the advantages of being continuous and rapid in production process, high in production efficiency, low in cost and the like and is suitable for large-scale production of graphite oxide and graphene.

The invention discloses a preparation method of a two-dimensional MoS2 nanosheet, and belongs to the field of nano materials. The preparation method of the two-dimensional MoS2 nanosheet comprises thefollowing steps: adding a certain amount of molybdenum disulfide polycrystal or ground MoS2 polycrystal powder into a certain volume of strong-activity alkali metal organic reagent under the condition of inert gas in a glove box, placing a sealed reaction kettle into a constant-temperature heating box at the temperature of 30-150 DEG C, and carrying heat treatment for 2-100 h; and completing reaction to obtain a black intercalation compound, after vacuum drying, adding the obtained intercalation compound powder into deionized water, meanwhile, carrying out ultrasonic-assisted stripping to prepare a single-layer MoS2 nanosheet in a stripping manner, and then carrying out ultrasonic crushing or grinding treatment on the polycrystalline MoS2 powder according to different sheet diameter requirements to obtain the nanosheet which is high in single-layer rate and controllable in size. The specific surface area of an electrode material is increased, and the excellent conductivity of the electrode material is guaranteed.

The invention discloses a preparation method of a graphene/ionic liquid composite material. The method comprises that: chloride intercalation graphite is taken to be added into the fused ionic liquid, stripping is performed under the effect of an alternating electric field, the obtained mixed liquor is centrifuged and supernatant is removed so that graphene is obtained; and the graphene is immersed into the ionic liquid again, filtering is performed and the filtered material is dried so that the graphene/ionic liquid composite material is obtained. The invention also discloses the graphene/ionic liquid composite material prepared via the aforementioned preparation method, a graphene/ionic liquid combined electrode manufactured by the composite material and the preparation method thereof and an electrochemical capacitor manufactured by the combined electrode. Defects of liable agglomeration and small specific area when the existing graphene acts as an electrode material independently can be overcome. Under the premise of not destroying the structure of the graphene, the graphene/ionic liquid composite material with high single-layer rate and great dispersity can be prepared so that preparation efficiency is high, source of raw materials is wide, cost is low and industrialization is easy to realize.

The invention discloses a preparation method of a graphene-ionic liquid composite material. The preparation method comprises mixing intercalated graphite with a molten ionic liquid in a solid-liquid ratio of 1g:10-100mL, stirring the mixture uniformly, and then putting the mixture into a microwave oven for stripping for 10 to 100 minutes with power being 1,000 to 2,000w, and obtaining the graphene-ionic liquid composite material. The invention further discloses the graphene-ionic liquid composite material made by using the preparation method, a graphene-ionic liquid composite electrode including the graphene-ionic liquid composite material, a preparation method of the graphene-ionic liquid composite electrode, and an electrochemical capacitor. The graphene-ionic liquid composite material which is intact in laminated structure, high in single layer rate and good in dispersibility is made by placing the intercalated graphite into the ionic liquid for microwave stripping. The prepared composite electrode does not need to use an adhesive or to prepare a current collector, and therefore the internal resistance of the electrode and the contact resistance are reduced, and the power density and energy density of the electrochemical capacitor are improved.

The invention discloses a continuous production device for aminated graphene and a method and belongs to the technical field of graphene preparation. The continuous production device comprises an acidtreatment device, an oxidation device, a first washing suction filtration device, a second washing suction filtration device, a dispersion treatment device, a first homogenization treatment device, afirst micro-reaction device, a first tubular reaction device, a second tubular reaction device, a first suction filtration and dispersion device, a second micro-reaction device, a third tubular reaction device, a fourth tubular reaction device, a second suction filtration and dispersion device, a third suction filtration and dispersion device, a first reaction product storage tank, a second homogenization treatment device, a third homogenization treatment device and a second reaction product storage tank; a static mixer is arranged inside a material conveying tube. Modified aminated grapheneproduced by using the device is small in piece size, narrow in piece diameter distribution, high in single layer rate, free of pollution in a production process, and a raw material base is provided for on-scale application of the aminated graphene.

The invention provides a preparation method of low-defect graphene coated aluminum powder particles. The preparation method comprises the following steps that 1) graphite is taken as an electrode, metal platinum is taken as a counter electrode, the electrode is inserted into an electrolyte aqueous solution and is connected to positive and negative electrodes of a direct current power supply, voltage is applied, current is introduced, and the graphite is expanded and dispersed in an electrolyte solution; 2) the collected expanded graphite powder is washed with water to remove electrolyte components, and then is dispersed in an organic solution, and ultrasonic treatment is carried out to obtain a graphene uniform dispersion liquid; and 3) aluminum powder or aluminum alloy powder is added into the graphene dispersion liquid, stirred and mixed, and then filtered and dried to obtain the composite aluminum powder material coated with the graphene coated aluminum powder. The graphene in the prepared graphene aluminum powder composite material is tightly adsorbed on the surface of the aluminum powder particles, the graphene oxidation degree is low, the structure and the chemical defects are few, and the electric conductivity and the heat conductivity of the composite material are high.

The invention relates to a high-energy catalytic physical stripping preparation method of graphene, relates to the technical field of graphene materials, and solves the problem that a conventional physical stripping method is high in cost and not easy to be mass-produced. The method specifically comprises the following steps: performing preliminary infiltration on pure water, performing first high-energy ultrasonic preliminary stripping, adding SiC for ball milling, then performing second high-energy catalysis for stripping, classifying graphene flakes by gas flow classification and spray-drying to obtain the graphene; by infiltration, ultrasonic treatment, SiC ball milling, addition of a surfactant and the secondary high-energy ultrasonic treatment, the graphene is stripped layer by layer, the process is mild, and basically no crushing and wear phenomena occur; the prepared graphene crystal lattice structure is complete and processed by a physical stripping method, the graphene flakesare present in a completely powdery form, the storage and use environments are not restricted, and the industrial production cost is relatively low, thereby facilitating the wider application of graphene in various industries.

The invention discloses a preparation method of a graphene/ionic liquid composite material. The method comprises that: chloride intercalation graphite is taken to be added into the fused ionic liquid, ultrasonic stripping is performed for 0.5-24 hours and then the obtained mixed liquor is placed in a constant electric field to be centrifuged, and supernatant is removed so that graphene is obtained; and the graphene is immersed into the ionic liquid again, the ionic liquid is removed via filtering and the filtered material is dried so that the graphene/ionic liquid composite material is obtained. The invention also discloses the graphene/ionic liquid composite material prepared via the aforementioned preparation method, a graphene/ionic liquid combined electrode manufactured by the composite material and the preparation method thereof and an electrochemical capacitor manufactured by the combined electrode. Defects of liable agglomeration and small specific area when the existing graphene acts as an electrode material independently can be overcome. Under the premise of not destroying the structure of the graphene, the graphene/ionic liquid composite material with high single-layer rate and great dispersity can be prepared so that preparation efficiency is high, cost is low and industrialization is easy to realize.

The invention provides a method for preparing graphene by alkali metal intercalation. The method comprises the following steps that (1) in an inert environment, a graphene material is mixed with alkali metal to obtain an evenly-mixed graphene carbon material-alkali metal composite material, still standing is conducted in the inert environment, and thus metal intercalation reaction is produced; and(2) the obtained composite material is put in a liquid medium reacting with the composite material to react, an intercalation object is removed, and the graphene material is obtained through vibration, washing and separating. The invention further provides the graphene prepared through the method. According to the preparation method of the high-quality graphene, a golden yellow composite materialobtained through lithium or other highly-reactive alkali metal mixed and reacted with the graphene material is adopted to serve as a precursor, the later stage preparation process of the graphene canbe conducted under condition of room temperature, air and the like, and the method is suitable for large-scale preparation of the graphene.