1948 results about "Grapheme" patented technology

A text-to-speech system adapted to operate on text in a first language including sections in a second language, includes a grapheme/phoneme transcriptor for converting the sections in the second language into phonemes of the second language; a mapping module configured for mapping at least part of the phonemes of the second language onto sets of phonemes of the first language; and a speech-synthesis module adapted to be fed with a resulting stream of phonemes including the sets of phonemes of the first language resulting from mapping and the stream of phonemes of the first language representative of the text, and to generate a speech signal from the resulting stream of phonemes.

The invention relates to a preparation method of a polymer/graphene composite material through in situ reduction, which is characterized by comprising the following steps: adopting ultrasonic wave or grinding to evenly disperse the graphite oxide prepared by a Hummers method into polymer dispersion; introducing reducing agent into the polymer dispersion for in situ reduction, enabling the graphite oxide to be reduced into the grapheme so as to obtain stable polymer/graphene composite emulsion; carrying out demulsification, agglomeration and drying to obtain the composite polymer/grapheme composite master batch; adding the dried polymer/grapheme composite master batch and various assistants into the polymeric matrix according to a certain ratio; and carrying out double-roller mixing, vulcanization, melt extrusion or injection molding to obtain the polymer/graphene composite material with excellent physical and mechanical properties.

The invention belongs to the fields of material synthesis and energy technology, and especially relates to a graphene/metal oxide composite cathode material for lithium ion batteries and a preparation method thereof. Grapheme is dispersed into various metal oxide precursor salt solutions; a graphene/metal oxide compound is obtained directly by a hydrothermal method, or an graphene/metal oxide compound is obtained by a liquid in-situ polymerization method or a coprecipitation process; and the graphene/metal oxide compound is obtained by heat treatment or hydrothermal treatment. In the invention, the novel three-dimensional composite cathode material of graphene-coated metal oxide or graphene-anchored metal oxide is prepared by carrying metal oxide particles with graphene as a carrier. The obtained composite material can be used as a lithium ion battery cathode, which has a high specific capacity, excellent cycle stability and rate capability, and is expected to be used as a lithium ion battery cathode material with a high energy density and a high power density.

The invention relates to a graphene-organic material layered assembly film and a preparation method thereof. The preparation method comprises: using a graphene material and an organic material as raw materials, utilizing interaction of static electricity, hydrogen bonds, coordinate bonds or charge transfer and the like between the graphene and the organic material, and superposing films layer by layer through the film preparation methods such as spin coating, spraying, dipping, lifting and pulling and the like to prepare the film, wherein the thickness of each layer of the film can be controlled between 10 nanometers and 2 millimeters according to requirement. The layered assembly film and the preparation method have the characteristics that multilayer film materials with different functions are prepared by utilizing unique electric, magnetic, mechanical and chemical properties of the grapheme, and can be used as biomaterials, conductive materials, electromagnetic shielding and wave absorbing materials, photovoltaic materials, electrode materials, film filtering and separating materials, and the like to be applied to chemistry and chemical industry, biology and precision instruments, and manufacture of micro electrons, machinery and aviation and aerospace devices according to the selected different organic materials.

The invention relates to a method for preparing graphene powder in large scale, which is characterized by comprising the following steps of: firstly, uniformly peeling graphene oxide into a graphene oxide suspension solution; then, atomizing the graphene oxide solution by using the spray drying technology comprising spray pyrolysis drying and spray freeze drying, and removing a solvent to obtain graphene oxide powder; and finally, oxidizing grapheme by using the non-expansion heat treatment process to obtain non-agglomerative graphene powder. The continuous preparation process of the spray technology and the non-expansion heat treatment process ensure the large-scale preparation of the graphene powder. The prepared graphene powder comprising intermediate product graphene oxide powder does not have agglomeration and has good dispersivity in the solvent. The graphene powder is used as a filling material to prepare high strength composite materials, conductive composite materials, novel air-tight flame-retardant composite materials, novel nanodevices and the like.

The invention discloses a graphene-based barrier composite material, which has high barrier and mechanical performance and is prepared by using grapheme sheets which are two-dimension nano materials as an intensifier and uniformly dispersing the grapheme sheets in a polyolefin polymer by chemical crosslinking. The preparation method of the barrier composite material comprises: 1, functionally modifying the surface of the graphene oxide by using coupling agent to graft active functional groups on the surface of the graphene oxide, and reducing the modified graphene oxide into grapheme; and 2, uniformly dispersing the modified graphene into solution of the polyolefin to perform crosslinking under the action of an initiator to obtain the nano composite material. In the invention, the raw material is low in cost and readily available; the operation is easy, the process is simple, the repeatability is high, the graphene can well disperse in the polyolefin, and the prepared graphene-based barrier composite material has high polar and nonpolar solvent barrier performance and is obviously improved in tensile strength and fracture toughness.

The invention provides nitrogen mixed grapheme hydrogel of which the water content is 90 to 99.5 percent, the electric conductivity is 10-3-100 S/m, and the molar ratio of N and C is 1 to 25 percent. The invention further provides nitrogen mixed aerogel of which the molar ratio of N and C is 2 to 20 percent, the molar ratio of C and O is 15 to 5, nitrogen atoms existing in the form of amidogen nitrogen accounts for 40 to 70 percent, pyridine type nitrogen accounts for 10 to 40 percent, graphite type nitrogen accounts for 10 to 30 percent, the specific area is 300 to 1500 m<2>/g, the apertures which are micropore account for 10 to 20 percent, the apertures which are mesoporous 20 to 50 percent, the apertures which are macropore 30 to 70 percent, the apparent density is 0.01 to 0.2 g/cm<3>, the pore volume is 5 to 20 cm<3>/g, and the electric conductivity is 1 to 1000 S/m. The nitrogen mixed grapheme hydrogel or aerogel and preparation method thereof provided by the invention has the characteristics that the operation is simple, the equipment requirement is low, the production efficiency is high, the scale-up of the technology is easy, the nitrogen mixed content is controllable and the compounding with other functional substances is simple.

The invention relates to a graphene-containing viscose fiber and a preparation method thereof. Graphene is non-oxidized graphene with a layer number not more than 10. The preparation method comprises the step of introducing the graphene into viscose before spinning. The viscose fiber obtained through the preparation method disclosed by the invention outstandingly enhances the fracture strength.

The invention discloses a grapheme/silicon composite material for a lithium ion battery cathode material and a preparation method thereof, belonging to the fields of electrochemistry and new energy materials. The method comprises the following steps of: using graphite as a raw material; oxidizing the graphite into oxidized graphite by adopting oxidants of concentrated sulfuric acid and potassium permanganate; then, ultrasonically stripping the oxidized graphite to prepare oxidized graphene; mixing oxidized graphene in different proportions with nano silicon powder; ultrasonically dispersing, filtering or directly drying into a cake/film; and roasting under a reduction atmosphere to prepare self-support graphene/silicon composite film materials in different proportions. Proved by electrochemistry tests, the graphene/silicon composite film material prepared by the method has higher specific capacity and cycle stability, simple preparation method and easy mass production and consequently is an ideal high-energy lithium ion battery cathode material.

The invention discloses grapheme foam and a preparation method thereof. The grapheme foam provided by the invention is prepared by the method comprising the following steps: 1) putting a metal foam material into a vacuum tube type furnace, and calcining the metal foam material under non-oxidizing atmosphere; 2) depositing grapheme on the calcined metal foam material by adopting a chemical vapor deposition method; and 3) removing foam metal from the obtained grapheme modified metal foam material, cleaning the obtained foam material by using deionized water, ethanol and ether in turn, taking the foam material out and drying the foam material to obtain grapheme foam. The grapheme foam material has a three-dimensional hollow porous netlike structure, the grapheme is on the netlike wall, and the structural characteristic effectively prevents the agglomeration of the grapheme; and the grapheme foam material integrates the characteristics of a foam material and a conductive material, and has the advantages of ultra-low density, ultra-high surface area, high heat conduction, high temperature resistance, corrosion resistance and the like.

The invention discloses a graphene with a porous structure and a preparation method of the graphene. The porous grapheme consists of a single-layer or multi-layer graphene structure unit, the single-layer or multi-layer grapheme structure unit has a pore-shaped structure (pore diameter is 0.1-200 nm) and a large specific surface area (300-2000 m<2>/g), thus the graphene has potential application value in the aspects of super-capacitors, conductive filling materials and the like. The preparation method of the porous grapheme is characterized in that MgO, Mg(OH)2, Al2O3, Al(OH)3, hydrotalcite compounds and/or corresponding calcined products of the substances are used as catalysts, or MgO, Mg(OH)2, Al2O3, Al(OH)3, hydrotalcite compounds and/or corresponding calcined products of the substances are used as carriers so as to further load one or more active components of Fe, Co, Ni and Mo and then the obtained substance is used as the catalyst ( the pore diameter of the catalyst is 1-200 nm, and the specific surface area is 10-300 m<2>/g); and then at the temperature of 300-1000 DEG C, the graphene is prepared by using inert gases such as nitrogen, argon, helium and the like and using a hydrocarbon chemical gas phase deposition method.

The invention relates to a preparation method of graphene based on ascorbic acid, belonging to the technical field of nano materials. The preparation method comprises the following steps: preparing brown graphite suspending liquid; preparing luminous yellow graphite diluent; preparing graphite oxide solid; dispersing graphite oxide into deionized water, separating graphene oxide by ultrasonic separation treatment for 1 hour and preparing graphene oxide solution; and fully mixing the graphene oxide solution and ascorbic acid water solution, stewing and obtaining the graphene solution. The preparation adopts the ascorbic acid as a reducing agent, shortens reaction time under the condition that no stabilizing agent is added, obtains single-layer grapheme with the thickness of 0.8 to 1.2nm and is beneficial to batch production of the grapheme.

The invention provides an oxidized grapheme/carbon black rubber nanocomposite and preparation method thereof, which belongs to the field of rubber nanocomposite technology. The nanocomposite comprises the following basic compositions by mass: 100 parts of diene series rubber matrix, 0.5-5 parts of oxidized grapheme, 30-70 parts of hard carbon black of average particle size 11-30nm, 1-10 parts of plasticizer, 6-10 parts of activator, 0.5-4 parts of anti-aging agent, 1-4 parts of sulfuration promoter and 1-6 parts of insoluble sulphur; oxidized grapheme modifier. The oxidized grapheme powder is dispersed in deionized water for ultrasound, and a natural rubber emulsion is added, and masterbatch after flocculation, washing and drying is mixed uniformly with other additives, after sulfuration, the product is obtained. The oxidized grapheme/carbon black rubber nanocomposite has the advantages of excellent processing performance and obviously reduced dynamic themogenesis, thereby improving the usage life of tyre.

The invention relates to a method for preparing grapheme through oxidation reduction and belongs to grapheme preparation technique. The method specifically comprises the following steps: a modified Hummer method is used for preparing graphite oxide, and an oscillator is adopted for shaking and peeling off single layer graphite oxide softly. During the step of preparing grapheme through reduction, compared with kinds of conventional major reducing agents, the method has the advantages that the reduction procedures and conditions are optimized, and further the grapheme with excellent performance is obtained. In the invention, by optimizing the preparation technique and conditions, the grapheme, which is large in size, is single-layered, is excellent in electrical conductivity and has high quality is obtained, and the method has the characteristics of low cost, high product yield and easiness in industrialization.

The invention belongs to the technical field of micro-nano manufacture, and particularly relates to a method for obtaining a graphene micro-nano structure by using graphene oxide as a raw material and utilizing a laser processing technology, which comprises the following steps of: firstly preparing a graphene oxide film on a substrate, and then building a laser micro-nano processing system for carrying out laser micro-nano processing for the graphene oxide to obtain the grapheme micro-nano structure on the substrate. The method has the following advantages: the method can prepare the micro-nano structure with various patterns easily; a three-dimensional structure can be realized by utilizing point-by-point processing; the conducting capability of the micro-nano manufacture can be regulated and controlled through controlling the reduction degree of a graphene material, and the reduction degree can be changed by changing laser processing power; and the adjustment of the graphene structure can be realized through the change of a processing atmosphere.

The invention provides a grapheme-coated sulfur/porous carbon composite material and a preparation method thereof, and relates to a grapheme-coated sulfur/porous carbon composite material used as the positive electrode material of a lithium-sulfur secondary battery and a preparation method thereof. The grapheme-coated sulfur/porous carbon composite positive electrode material provided by the invention can be used for solving the technical problem that the existing grapheme-coated sulfur-containing composite material used as the positive electrode material of a lithium-sulfur battery is low in electrochemical properties. The external surface of each of the particles of the grapheme-coated sulfur/porous carbon composite material provided by the invention is evenly covered with a graphene sheet, and a graphene conductive network is formed between the particles; the obtained grapheme-coated sulfur/porous carbon composite material has a hierarchical core-shell structure. The preparation method of the grapheme-coated sulfur/porous carbon composite material is obtained by adding a sulfur/porous carbon composite material to graphene slurry which is stable for a long time and in which graphene sheets are highly dispersed in water for mixing and coating. The positive electrode material has high specific capacity, long cycle life and excellent high-rate performance. Besides, the grapheme-coated sulfur/porous carbon composite material can be used as the positive electrode material of a lithium secondary battery.

The invention discloses an oxidized grapheme/polyaniline super capacitor composite electrode material and the preparation method and the application thereof. The preparation method comprise the following steps: firstly, adding oxidized graphite to water for ultrasonic dispersion so as to form an oxidized grapheme solution with uniformly dispersed single pieces; at room temperature, dropping aniline to the obtained oxidized grapheme solution for continuous ultrasonic dispersion to from a mixed solution; at a low temperature condition, adding hydrogen peroxide, ferric trichloride and a hydrochloric acid solution dropwise to the mixed solution, and stirring the solution for polymerization; and after the reaction is finished, centrifugating, washing and roasting the obtained mixed solution in vacuum to obtain the oxidized grapheme/polyaniline super capacitor composite electrode material which is used as the electrode material of an electricity storage system of a super capacitor and a battery. The oxidized grapheme/polyaniline super capacitor composite electrode material with good electrochemistry performance is obtained by the method, and the specific capacity of the oxidized grapheme and the polyaniline is greatly improved. In addition, the addition of the oxidized grapheme improves the charge and discharge service life of the polyaniline.

The invention discloses carbon nano tube electric conduction slurry and a preparation method and the application of the carbon nano tube electric conduction slurry. The carbon nano tube electric conduction slurry is composed of, by mass, 2% to 10% of electric conduction function body, 0.2% to 5% of dispersing agent and 85% to 97.8% of solvent. The electric conduction function body is spherical carbon nano tube groups or spherical carbon nano tube aggregates or the combination between the spherical carbon nano tube groups or the spherical carbon nano tube aggregates and one or more of carbon black, acetylene black, carbon fibers, conductive graphite and grapheme. The preparation method comprises the steps that the electric conduction function body and the dispersing agent are added into the solvent according to the percentage to be mixed, premix is obtained, the premix is ground in a grinding machine, and the electric conduction slurry containing a plurality of spherical carbon nano tube groups with the grain size ranging from 0.1 micron to 3 microns is formed. The carbon nano tube electric conduction slurry can be used as electric conduction agents of positive electrode and negative electrode materials of a lithium battery. According to the electric conduction slurry, an electric conduction network coating base materials is easily formed, the preparation technology is simple, production efficiency is high, and the obtained carbon nano tube slurry is good in stability and long in shelf life.

The invention provides a preparation method of dispersible silane functionalized graphene. The method comprises the steps of: conducting ultrasonic dispersion to graphene oxide in absolute ethyl alcohol so as to form a uniform graphene oxide dispersion solution, then adjusting the pH value to 3-4, or under the protection of an inert atmosphere, adding silane into the dispersing solution for modification, with silane and graphene oxide in a mass ratio of 0.1:1-5:1, continuing the reaction for 12h-48h at a temperature ranging from normal temperature to 78DEG C, carrying out centrifugation, then adding hydrazine hydrate to the obtained solid, performing heating reduction, and filtering the reaction solution, then washing and drying the filter cake, thus obtaining dispersible silane functionalized grapheme. The method of the invention is simple and practicable, and the obtained silane functionalized grapheme has good dispersibility in solvents like absolute ethyl alcohol, acetone, toluene, ethyl acetate, butyl acetate, and tetrahydrofuran (THF), etc.

The invention relates to a method for simply and innoxiously preparing single-layer graphene, belonging to the chemical field of inorganic field. The technical processes of the invention are as follows: adopting a fixed amount of natural graphite powder; oxidizing the natural graphite powder in a strong oxidizing condition to obtain the graphite oxide; dispersing the obtained graphite oxide in the de-ionized water; then ultrasonically processing for a certain period in an ultrasonic machine to peel the graphite oxide off into single-layer graphite oxide sheet; then dispersing the graphite oxide sheet in the dimethylsulfoxide solution; transferring the mixture solution to a reaction kettle and reacting for 10 to 16 hours in 150 to 200 degrees centigrade; after filtered, obtaining the mass colour product, that is, single-layer grapheme. The invention adopts nontoxic reducing agent, dimethylsulfoxide, so it is good for environment protection. The invention has simple technique, operation convenience, and low manufacturing cost.

The invention belongs to the technical field of materials and in particular relates to a graphene coating as well as a preparation method and a coating method thereof. The graphene coating is prepared from the components by weight: 5-95wt percent of less layer of grapheme, 5-95wt percent of adhesive, 0.01-50wt percent of dispersant and surfactant, 0.01-10wt percent of defoamer and the balance of solvent. With the adoption of the graphene coating, the thickness of an electricity and heat conductive coating can be controlled to be 100nm-20 microns; when the graphene coating is used on a plastic matrix, the volume resistivity can reach a range from 10<-2>ohm.cm to 10<-4>ohm.cm; while the graphene coating is used on a metal matrix, the volume resistivity can reach 10<-6>ohm.cm. The graphene coating can be applied to the metal surface so as to improve the cohesiveness, the electricity/heat conduction performance and the corrosion and oxidation resistance. When the graphene coating is coated on the plastic surface, the frictional resistance, the electricity and heat conduction performances and the static resistance can be lowered, and the graphene coating can be applied to the fields of printed circuits, electronic devices, radio frequency devices, touch screens, thin film solar energy, LEDs, magnetic shielding, radio frequency shielding and the like.

The invention relates to a transition metal oxide/ graphene nanometer composite electrode material used for a lithium battery and a preparation method thereof. The transition metal oxide/ grapheme nanometer composite electrode material is the transition metal oxide modified by grapheme or graphene oxide, wherein the transition metal oxide and the grapheme or the graphene oxide can be connected in a physical packaging or chemical bonding mode. One of the following methods is adopted: 1. evenly mixing a precursor and graphene (or graphene oxide) required by preparing the transition metal oxide at the mass ratio of 0.01: 100 to 50: 100 in a solvent, and reacting at a certain temperature and pressure to obtain the nanometer composite electrode material; and 2. fully mixing the graphene (or graphene oxide) and the transition metal oxide at the mass ratio of 0.01: 100 to 50: 100 in a solvent, and drying to obtain the nanometer composite electrode material. The preparation method is simple, is easy to operate and is suitable for large-scale production, the prepared electrode material has higher lithium-ion and electron conductivity, and the assembled lithium battery has the advantages of high lithium battery specific capacity and good cycle performance and is suitable for the lithium battery electrode material.

The invention relates to a method of producing grapheme, which is characterized by comprising the following steps: (1) mixing the raw material of graphite powder with organic solvent according to theconcentration of 1-100 mg/ml to form suspension, and adding grinding balls to the suspension; (2) grinding and dispensing the suspension by a ball-grinding machine for 0.5-6.0h, and taking out slurry;(3) carrying out ultrasonic processing to the slurry for 0.5-6.0h; (4) separating the slurry centrifugally at high speed to obtain the upper solution which is the mixed colloid of monolayer graphemeand multilayer grapheme; and (5) concentrating, separating and replacing the solvent of the mixed colloid of the monolayer grapheme and the multilayer grapheme to obtain grapheme powder and stable grapheme colloid. The invention can consecutively produce the high-conductivity high-thermal conductivity grapheme which is dispersive and stable on a large scale with lost cost by using noncorrosive poisonous flammable and combustible raw materials without discharging waste water and waste gas.