24 results about "Hummers' method" patented technology

The invention provides a preparation method of a graphene carbon nanofiber film for oil-water separation, and relates to the field of oil-water separation membranes, and the preparation method comprises the following steps: mixing polyacrylonitrile powder and an N, N-dimethylformamide solution to obtain an electrostatic spinning solution; spinning through an electrostatic spinning machine to obtain a polyacrylonitrile fiber membrane; coating the polyacrylonitrile fiber film with the prefabricated graphene oxide dispersion liquid to obtain a graphene oxide / polyacrylonitrile composite film; carrying out pre-oxidation, activation and carbonization treatment on the composite film to obtain a graphene carbon nanofiber film; according to the method, the waste isostatic pressing graphite which is low in price and easy to obtain is adopted as the raw material, the ammonia activation means is combined, improvement is carried out on the basis of a Hummers method, graphene oxide is prepared, resource recycling is achieved, the isostatic pressing graphite waste generated in the production process is recycled and processed into a product with a high additional value, and therefore the purposes of reducing the production cost and saving resources are achieved.

The application discloses a graphene dispersion liquid and a preparation method thereof, relates to the field of graphene dispersion liquid and a preparation method thereof, and aims at solving the technical problem that it is difficult to obtain a high-concentration stable graphene dispersion liquid at present. In the dispersion liquid, graphene is obtained by reduction of graphene oxide prepared by a Hummers method, and then is uniformly dispersed into N-methyl pyrrolidone under the assistance of dispersants of sodium polystyrene sulfonate and polydiallyldimethylammonium chloride. The application is used for preparing the graphene dispersion liquid.

This invention discloses an interlayer confined piezoelectric composite film of graphene oxide, its electric field-driven preparation method, and its application. The preparation method includes: preparing a graphene oxide dispersion using the Hummers method and filtering it to form a graphene oxide film; placing the graphene oxide film in an electric-driven device, introducing different precursor solutions on both sides of the film, and driving the precursor components to migrate into the interlayer confined space of the graphene oxide under the action of an applied electric field; under the synergistic effect of electric field driving and interlayer confinement, the precursors entering the interlayer react and crystallize in situ to form a piezoelectric functional phase. The prepared composite film can generate piezoelectric polarization under mechanical stimulation conditions and can be used for ion selective adsorption / separation, especially suitable for the selective adsorption / separation of uranium and vanadium ions in high-salt water systems. This invention achieves a synergistic improvement in interfacial charge regulation and ion selectivity regulation by constructing a piezoelectric functional phase in situ within the interlayer confined space of graphene oxide.

The invention discloses a preparation process of graphene oxide liquid phase coated nano silicon. The preparation process comprises the following steps: S1, preparing modified nano silicon; s2, preparing a graphene oxide dispersion liquid; step S3: construction of a pre-coating system; s4, carrying out dynamic liquid phase coating reaction; step S5, post-treatment and purification; nano silicon is modified before coating, amino active groups are introduced to the surface of the nano silicon through gamma-aminopropyltriethoxysilane and can interact with carboxyl and hydroxyl on the surface of graphene oxide, the interfacial compatibility of the nano silicon and the graphene oxide is remarkably improved, and the binding force between a coating layer and the nano silicon is enhanced; the falling of the coating layer in the charging and discharging process is effectively inhibited; according to the preparation method, the graphene oxide is prepared by adopting an improved Hummers method, the dispersing agent is added, a stirring-ultrasonic dispersion process is combined, and meanwhile, the temperature in the ultrasonic process is controlled, so that the dispersity of the graphene oxide is effectively improved, agglomeration of the graphene oxide is avoided, and a foundation is laid for subsequent uniform coating.

The invention discloses a preparation method of a floating type cocatalyst and application of the floating type cocatalyst in Fenton reaction. Nano tungsten sulfide prepared by a hydrothermal method and graphene oxide prepared by a Harmer method are used as raw materials, and the floating type cocatalyst is synthesized by a simple impregnation method. The prepared cocatalyst (MS-WS2-GO) can effectively promote the circulation rate of Fe < 3 + > / Fe < 2 + >, the cocatalysis Fenton-like system can achieve the removal effect of 90% or above on organic pollutants in water only under the condition that 0.5 mM H2O2 and 20 mg / L FeSO47H2O are added, and the system does not generate iron mud. The MS-WS2-GO / Fenton small-scale test system constructed by the invention is continuously operated for 31 days, and the degradation rate of sulfamethoxazole is still kept to be 100% or above. The preparation process of the floating type cocatalyst is mild in condition, simple and convenient to operate and easy to implement.

The invention relates to a natural latex / graphene aerogel composite material for oil-water separation and a preparation method thereof. The preparation method comprises the following steps: firstly, preparing graphene oxide by an improved Hummers method, and then preparing the natural latex / graphene aerogel by combining a hydrothermal self-assembly method, a bubble template method and a freeze-drying method. And then adjusting the use amount of the natural latex and process parameters to optimize the performance of the natural latex / graphene aerogel, thereby preparing the natural latex / graphene aerogel with optimal performance. The preparation method has the beneficial effects that the problem of oil-water separation performance is solved, excellent adsorption performance is shown on organic reagents (ethanol, n-butane, liquid paraffin, trichloromethane, xylene, kerosene, edible oil, cyclohexane and the like), and the adsorption range is 43.82-189.86 g / g; after 10-20 times of cycle tests, the thickness recovery rate and the absorption capacity are still 92% or above of the initial value.

This invention provides a method for preparing graphene quantum dots based on thermal coal and a plasma reaction system, belonging to the field of graphene quantum dot preparation technology. The method includes the following steps: using thermal coal as raw material, it undergoes electrochemical oxidation and KOH ball milling sequentially to obtain pretreated coal; the pretreated coal is introduced into an axial magnetic rotating microwave plasma reactor for segmented temperature-controlled dissociation and recombination reactions; during the reaction, a porous alumina template is used for confined growth, and after the reaction, liquid nitrogen quenching is employed to obtain graphene quantum dots. This invention uses thermal coal to replace high-purity graphite as the carbon source, reducing raw material costs by more than 99%; the pretreatment process, through the synergistic effect of electrochemical oxidation and KOH ball milling, eliminates the need for strong acids and alkalis throughout, completely avoiding the pollution problems of large amounts of acidic and heavy metal-containing wastewater and waste gas generated by the traditional Hummers method, thus aligning with the concepts of green chemistry and sustainable development.

The invention relates to a graphene oxide modified cement-based capillary crystalline coating and application thereof, and relates to the technical field of concrete durability protective materials. The coating comprises a cement-based gelling component, a capillary crystalline active component, a filler component and a graphene oxide dispersion system, graphene oxide is prepared through an improved Hummers method and subjected to composite stabilization treatment through a polycarboxylic acid water reducer, and it is ensured that the graphene oxide is stably dispersed in a high-alkali and high-calcium environment; during construction, the components are mixed in proportion to prepare slurry, the surface of the pretreated concrete is coated with the slurry, and the slurry is cured to form a compact protective layer. Under the condition that a conventional construction technology is not changed, the carbonization resistance of the concrete can be remarkably improved, and the method is suitable for durability protection and repair of various concrete structures.

The application discloses a method for preparing a graphene double-layer heterogeneous wave-absorbing structure based on fused deposition 3D printing, and relates to the technical field of wave-absorbing materials. The method comprises the following steps: original graphene is oxidized by adopting a Hummers method, and then macromolecular chains are grafted through derivative modification to obtain modified graphene; printing wire materials of a wave-transparent layer are prepared from the modified graphene; printing wire materials of a wave-absorbing layer are prepared from the original graphene and the modified graphene; the printing wire materials of the wave-transparent layer are used to print and prepare a wave-transparent layer cube with the modified graphene oriented along an X-0° direction, then the wave-transparent layer cube is cut perpendicularly to the X direction to obtain a flat plate with the modified graphene oriented along a Z-0° direction; and the flat plate is used as a substrate, and the printing wire materials of the wave-absorbing layer are used to print and prepare a wave-absorbing layer cube with the original graphene and the modified graphene both oriented along an X-Y direction on the substrate, so that the double-layer heterogeneous wave-absorbing structure is obtained. The structure of the application exhibits excellent wide-frequency wave-absorbing capacity under low graphene content, and has excellent mechanical properties.

The application discloses a preparation method of graphite oxide and graphene oxide, which comprises the following steps: (1) adding a nitric acid compound, concentrated sulfuric acid and graphite into a reaction system first, then adding a defect manufacturing agent, and reacting for 10-20 minutes at a temperature of 40-80 DEG C; according to the mass, the adding proportion of the concentrated sulfuric acid, the defect manufacturing agent and the graphite is 80-100:0.3-0.1:1, and the adding amount of the nitric acid compound is 10-40% of the solute H2SO4 of the concentrated sulfuric acid; the defect manufacturing agent is a high-valence salt or high-valence oxide of a vanadium group, a chromium group or a manganese group metal; (2) continuously adding 2-5 parts of an oxidant according to the mass of the graphite, and reacting for no less than 6 hours at the same reaction temperature to obtain graphite oxide. The Hummers method is improved, the use amount of a strong oxidant is greatly reduced, the oxidation performance requirement of the oxidant is lowered, the reaction process is more gentle, and the obtained graphite oxide can be ultrasonically stripped to obtain graphene oxide, and the post-processing is simple.

The application belongs to the field of waste lithium ion battery recycling, and discloses a method for preparing an iron-doped graphene catalyst by using waste lithium iron phosphate batteries, which comprises the following steps: discharging, disassembling and separating the waste lithium iron phosphate batteries to obtain lithium iron phosphate powder and graphite; obtaining a lithium and iron-containing precursor solution by acid leaching and oxidizing the lithium iron phosphate powder; adjusting the pH to obtain an iron hydroxide precipitate; co-heating and reducing the iron hydroxide precipitate with the graphite to obtain elemental iron; preparing graphite oxide from the graphite by using the Hummers method; reducing the graphite oxide at high temperature to obtain graphene; and realizing iron doping by high-temperature solid-phase synthesis; realizing good industrial catalysis by the nanoscale complex effect of iron and graphene; and successfully realizing application in Li-CO2 batteries, with excellent catalytic effect, and the remaining lithium precursor solution in the reaction can be further used to extract lithium. According to the treatment method, the process is simple, the operation is simple, a high-value chemical catalyst can be obtained, and the economic benefit is high.

The application discloses a method for preparing high-strength pure graphene fibers by using Tesla valve microchannels, and the method comprises the following steps: preparing graphene oxide by an improved Hummers method, layering and centrifugal separating the graphene oxide by peeling, and concentrating to obtain a graphene oxide aqueous solution; adding a DMF solvent into the graphene oxide aqueous solution, stirring uniformly, and then centrifugal separating to obtain a DMF solution of the graphene oxide; performing microfluid wet spinning on the DMF solution of the graphene oxide by using a Tesla valve microchannel to obtain graphene oxide fibers; and performing a reduction reaction on the graphene oxide fibers, and the high-strength pure graphene fibers are obtained. The special structure of the Tesla valve microchannel is combined with the wet spinning technology, the preparation of the high-orientation high-strength pure graphene fibers is successfully realized, and the problem of low fiber orientation in the traditional fiber preparation method is effectively overcome by optimizing the microfluid wet spinning process and post-processing technology.

The invention provides positive electrode slurry and a preparation method thereof, a pre-lithiated positive electrode and a battery, and relates to the field of lithium ion batteries. According to the positive electrode slurry provided by the invention, the compound of lithium oxalate wrapped by graphene or a derivative of graphene is compatible with the catalyst, the wrapping material is selected from one of graphene oxide, fluorinated graphene and hydrogenated graphene, and the wrapping layer can prevent lithium oxalate from caking, can improve the conductivity and remarkably improves the first charge specific capacity of the battery. And the coating can be prepared on a large scale through a liquid phase treatment method, such as a Hummers method and the like. The method is relatively simple, low in cost and high in economic benefit, and can be carried out on a chemical production line or in production equipment, so that industrial production is realized.

This invention relates to the field of lead-acid battery technology, and discloses a negative electrode paste for lead-acid batteries containing heterogeneous graphite and composite additives, and its preparation method, solving the problems of uneven graphite dispersion, weak interfacial bonding, stress concentration in the negative electrode grid, and short battery cycle life in the prior art. The negative electrode paste is based on lead powder and contains 0.5%~1.5% nano-scale thin-layer heterogeneous graphite, 0.5%~2.0% barium sulfate, 0.1%~1.0% carbon black, 0.1%~0.5% sodium lignosulfonate, 0.1%~0.15% polycarboxylate superplasticizer, and 0.05%~0.2% short fibers. The preparation includes: preparing nano-scale thin-layer heterogeneous graphite by modifying the nano-scale thin-layer with a silane coupling agent using a modified Hummers method combined with intermittent ultrasonic exfoliation; preparing the lead paste by adding acid in batches under vacuum stirring; applying the paste by vacuum atomization; and three-stage low-temperature curing of the negative electrode grid. This invention achieves the synergistic effect of composite additives to construct a stable three-dimensional conductive network. The prepared lead paste enables the battery to have a cycle life of ≥800 cycles, a capacity retention rate of ≥85% after 800 cycles, and a capacity retention rate of ≥80% at a low temperature of -18℃.

The invention discloses a method for preparing a high-conductivity lithium battery copper foil through hydroxylation modified graphene co-deposition, which comprises the following steps: S1, synthesizing graphene oxide by adopting an improved Hummers method: in an ice bath, adding natural graphite and NaNO3 into a mixed acid of concentrated sulfuric acid and phosphoric acid, and stirring for 1 hour to fully disperse the graphite; adding KMnO4 in three times, continuously stirring for 20 minutes, removing the ice bath, heating the reaction system to 50 DEG C, continuously stirring for 24 hours until the solution gradually becomes a brownish black viscous material, adding 30% H2O2 until the color of the solution becomes bright yellow from brownish black, washing the product with a 5% HCl solution for three times, and washing with deionized water until the product is neutral for later use. Graphene subjected to hydroxylation treatment is introduced in the preparation process of the electrolytic copper foil, and copper and functionalized graphene are synchronously deposited on the surface of a cathode by utilizing an electrochemical co-deposition technology, so that the copper foil for the lithium ion battery with high conductivity, high mechanical strength and good interface stability is obtained.

Disclosed is a method for synthesizing a reduced graphene oxide (rGO)-coated silicon-lithium titanium oxide composite for improving lithium-ion battery efficiency, wherein in order to alleviate volume expansion of Si and improve electrochemical performance, Si particles are uniformly embedded in lithium titanium oxide (LTO) and rGO is applied on the LTO by spray drying to synthesize a rGO@SLTO composite. A method for synthesizing a rGO-coated silicon-lithium titanium oxide composite for improving lithium-ion battery efficiency according to the present invention comprises: a first step for uniformly mixing Si powder and lithium titanium oxide powder by ball milling; a second step for treating the mixture of the first step by chemical vapor deposition to prepare silicon lithium titanium oxide (SLTO); a third step for synthesizing graphite into graphene oxide (GO) by the Hummers method; and a fourth step for mixing the GO with the SLTO, and then producing a rGO@SLTO composite by spray drying and chemical vapor deposition.

The present disclosure relates to a copper-manganese composite adsorption material and graphite oxide and a preparation method and application thereof, the copper-manganese composite adsorption material prepared by the method comprises copper elements, manganese elements, sulfur elements, potassium elements and oxygen elements, and the method comprises the following steps: preparing graphite oxide by using an improved Hummer method, performing solid-liquid separation on the obtained material to obtain a filtration stock solution and the graphite oxide; and performing hydrothermal treatment on a mixture of a copper source and the filtration stock solution of the graphite oxide to obtain the copper-manganese composite adsorption material.The copper-manganese composite adsorption material prepared by the method exhibits excellent performance in a hydrogen purification reaction process, and can remove sulfides in hydrogen at a temperature lower than 50 DEG C, and the content of sulfides in the purified hydrogen can meet the standard requirements of fuel cell hydrogen on the content of sulfides.

The present application belongs to the field of environmental governance and biology, and provides a method for degrading new pollutants by co-culturing microalgae and graphene oxide, comprising the following steps: S1, preparing graphene oxide by Hummers method and performing ultrasonic dispersion pretreatment; S2, expanding freshwater algae Synedra ulna to the logarithmic growth phase in SE culture medium, collecting the algal cells and adjusting to the target density; S3, mixing the graphene oxide prepared in S1 with the algal liquid in S2, and co-culturing under the conditions of light and shaking table; S4, adding wastewater containing new pollutants to the co-culturing system, and removing the pollutants by the adsorption of graphene oxide and the metabolic degradation of microalgae; S5, regularly sampling and analyzing the concentration change of the pollutants, and evaluating the degradation efficiency; by co-culturing graphene oxide and Synedra ulna, the present application completely mineralizes the pollutants by the synergistic effect of GO adsorption and algal degradation, significantly improves the removal efficiency of refractory pollutants, and widens the application range.

The application provides a preparation and application of a graphene and lithium iron phosphate composite material synthesized by Joule heat, and relates to the technical field of new energy lithium ion battery material synthesis. The preparation of the graphene and lithium iron phosphate composite material comprises the following steps: S101, a product obtained by acid treatment and heat treatment of natural graphite is a graphite precursor, and then the graphite precursor is used to prepare super-large flake graphene oxide by a modified Hummers method; S102, the super-large flake graphene oxide in the step S101 is converted into large flake low-defect graphene material by high voltage, high heat and high pressure of rapid Joule heat; and S103, the graphene material in the step S102 and lithium iron phosphate powder are transferred into a ball mill for ball milling, and finally a composite material is obtained. In the application, the performance of the lithium iron phosphate battery is improved by means of doping and coating, and a new electrode material is adopted to optimize the battery structure, so that the energy density and low-temperature performance are improved, and a green and low-cost preparation method is developed to reduce the production cost.

The application discloses a preparation method of a barrier antibacterial TPU composite film. Graphene oxide is prepared by using an improved hummers method, fluorinated graphene is prepared by using hydrofluoric acid as a fluorine source, the fluorinated graphene is used as a carbon source, and fluorinated graphene quantum dots are prepared under the action of an oxidant and an alkaline condition. Chitosan is dissolved in an acetic acid solution and reacts with the FGQDs under the action of dodecanol to form a barrier antibacterial agent CS / FGQDs. The TPU composite film produced by using the barrier antibacterial agent not only has a certain improvement in antibacterial performance, but also has improved barrier performance, and can generate great social and economic benefits.

A preparation method of a glass fiber / graphene oxide / metal electromagnetic shielding composite material, comprising the following steps: S1: repeatedly centrifuging and washing an oxide graphene diluent liquid prepared by a Hummers method to obtain neutral layered oxide graphene; S2: impregnating the neutral layered oxide graphene on a glass fiber fabric, drying to obtain a GF@GO composite material; S3: sequentially performing silver-ammonia solution coordination activation, formaldehyde reduction treatment and chemical copper plating treatment on the GF@GO composite material to obtain a GF@GO-Cu composite material; and S4: performing ultrasonic induction nickel-phosphorus nucleation and adsorption treatment on the GF@GO-Cu composite material through an ultrasonic activation solution, and then performing chemical nickel plating treatment to obtain a GF@GO-Cu / Ni composite material. The method has the characteristics of simple process, low cost, good mechanical strength and shielding performance.

The application belongs to the technical field of catalytic materials, and discloses a simple preparation method and application of a high-load oxygen ligand nickel monatomic composite graphene base catalyst. The catalyst is prepared by using the graphene oxide peeled off by the improved Hummer method as a carrier to load highly dispersed monatomic nickel salt under the condition of no high temperature and high pressure, using the energy change of graphene reduction to connect the nickel metal and the carrier, and using a simple one-step co-reduction method to obtain the high-load oxygen ligand nickel monatomic composite graphene base catalyst. The catalyst has high catalytic activity, excellent metal dispersion, high specific surface area, and high metal monatomic load, and can be used for catalytic oxidation of various volatile organic pollutants, and has high practical significance.

This invention relates to the field of water treatment membrane technology and discloses a composite reverse osmosis membrane system with a graphene oxide surface passivation layer. The system comprises: a reverse osmosis membrane base layer with a dense RO layer formed by interfacial polymerization; a graphene oxide passivation layer attached to its surface; and a graphene oxide surface modification layer on the surface of the passivation layer. The passivation layer is formed by coating and vacuum filtration of a graphene oxide suspension with 5-15 layers prepared by a modified Hummer method. It can form a strong repulsion layer against high-valence ions in water through its two-dimensional pi-electron structure, achieving passivation protection of the membrane surface. The modification layer is a 2-10 nm thick film prepared by chemical vapor deposition. The modifier is one or more of ethylene, propylene, and styrene, which can improve the bonding force and mechanical strength between the graphene oxide and the membrane base layer. This invention can simultaneously improve the antifouling properties, operational stability, and service life of the reverse osmosis membrane.

The invention discloses a high-iron-phase high-strength cement clinker and a preparation method thereof, and belongs to the field of cement clinker preparation. The cement clinker takes white mud, a waste desulfurizer, steel slag fine powder and blast furnace slag as raw materials, and is prepared by the following steps: dispersing with ethylene glycol, carrying out microwave treatment, adding calcium oxide, reacting at 50-75 DEG C, co-grinding with fly ash, purifying, and modifying high-activity acryloyl chloride to obtain a waste activator; and finally, the mixture is mixed with raw materials such as Hummers-method graphene oxide, limestone and the like, so that the water reducing agent is prepared. The prepared cement clinker is high in solid waste utilization rate, the early-stage compressive strength is larger than 55 MPa, the problem that in the prior art, the early-stage strength of a high-iron-phase cement clinker is insufficient is solved to a certain extent, meanwhile, the corrosion resistance of the cement clinker is enhanced by means of an intercalated organic reagent, the service life of the cement clinker is prolonged, the 180-day seawater corrosion attenuation rate is smaller than 10%, and the cement clinker has the good comprehensive performance. The method can be suitable for preparation of high-strength cement in various scenes.