2794results about "Carbon preparation/purification" patented technology

This invention relates to rigid porous carbon structures and to methods of making same. The rigid porous structures have a high surface area which are substantially free of micropores. Methods for improving the rigidity of the carbon structures include causing the nanofibers to form bonds or become glued with other nanofibers at the fiber intersections. The bonding can be induced by chemical modification of the surface of the nanofibers to promote bonding, by adding "gluing" agents and/or by pyrolyzing the nanofibers to cause fusion or bonding at the interconnect points.

Field emission display and method for fabricating the same, the field emission display including a cathode array having a cathode electrode formed on a substrate, insulating layers and carbon nanotube films for use as emitter electrodes formed alternately on the cathode electrode, and a gate electrode formed on the insulating layer, thereby permitting fabrication of a large sized cathode plate at a low cost because the film is formed by screen printing and exposure, which can reduce the cumbersome steps in fabrication of the related art Spindt emitter tip, and both a low voltage and a high voltage FEDs because the carbon nanotube film used as the emitter has a low work function, with an easy and stable electron emission capability.

Diatomic hydrogen and unsaturated hydrocarbons are produced as reactor gases in a fast quench reactor. During the fast quench, the unsaturated hydrocarbons are further decomposed by reheating the reactor gases. More diatomic hydrogen is produced, along with elemental carbon. Other gas may be added at different stages in the process to form a desired end product and prevent back reactions. The product is a substantially clean-burning hydrogen fuel that leaves no greenhouse gas emissions, and elemental carbon that may be used in powder form as a commodity for several processes.

This invention is directed to making chemical derivatives of carbon nanotubes and to uses for the derivatized nanotubes, including making arrays as a basis for synthesis of carbon fibers. In one embodiment, this invention also provides a method for preparing single wall carbon nanotubes having substituents attached to the side wall of the nanotube by reacting single wall carbon nanotubes with fluorine gas and recovering fluorine derivatized carbon nanotubes, then reacting fluorine derivatized carbon nanotubes with a nucleophile. Some of the fluorine substituents are replaced by nucleophilic substitution. If desired, the remaining fluorine can be completely or partially eliminated to produce single wall carbon nanotubes having substituents attached to the side wall of the nanotube. The substituents will, of course, be dependent on the nucleophile, and preferred nucleophiles include alkyl lithium species such as methyl lithium. Alternatively, fluorine may be fully or partially removed from fluorine derivatized carbon nanotubes by reacting the fluorine derivatized carbon nanotubes with various amounts of hydrazine, substituted hydrazine or alkyl amine. The present invention also provides seed materials for growth of single wall carbon nanotubes comprising a plurality of single wall carbon nanotubes or short tubular molecules having a catalyst precursor moiety covalently bound or physisorbed on the outer surface of the sidewall to provide the optimum metal cluster size under conditions that result in migration of the metal moiety to the tube end.

A carbon monolith includes a robust carbon monolith characterized by a skeleton size of at least 100 nm, and a hierarchical pore structure having macropores and mesopores.

Ultradispersed ones of primary particles of nanometer-sized carbon are obtained by applying a wet-type milling method and/or a wet dispersion method to an aggregate structure of the primary particles to overcome van der Waals forces, by which forces the primary particles are held together to form the aggregate structure, whereby the ultradispersed primary particles are obtained in a colloidal dispersion on a large-scale basis at low cost without using any additive. In a method of manufacturing the ultradispersed primary particles, the wet-type milling method is carried out in a ball mill, preferably in combination with a high-energy ultrasonic-wave process carried out in a dispersing medium such as pure water, whereby a colloidal solution or slurry with a low-concentration of the primary particles ultradispersed in the dispersing medium is obtained.

A carbon fine powder is obtained by uniformly coating the surface of a carbon fine powder having a large specific surface area with a uniform thin film layer of a metal oxide, metal nitride or metal carbide as an electrode active substance material through induction of a sonochemical reaction. It is found that the obtained carbon fine powder has a low electrical resistance and shows a rapid faradaic process (pseudo-capacitance) of the surface coating layer. The coated carbon fine powder, a process for producing the same, and a supercapacitor and a secondary battery using the carbon fine powder are disclosed.

The present application is generally directed to ultrapure synthetic carbon materials having both high surface area and high porosity, ultrapure polymer gels and devices containing the same. The disclosed ultrapure synthetic carbon materials find utility in any number of devices, for example, in electric double layer capacitance devices and batteries. Methods for making ultrapure synthetic carbon materials and ultrapure polymer gels are also disclosed.

The present invention discloses the process of supplying high pressure (e.g., 30 atmospheres) CO that has been preheated (e.g., to about 1000° C.) and a catalyst precursor gas (e.g., Fe(CO)₅) in CO that is kept below the catalyst precursor decomposition temperature to a mixing zone. In this mixing zone, the catalyst precursor is rapidly heated to a temperature that results in (1) precursor decomposition, (2) formation of active catalyst metal atom clusters of the appropriate size, and (3) favorable growth of SWNTs on the catalyst clusters. Preferably a catalyst cluster nucleation agency is employed to enable rapid reaction of the catalyst precursor gas to form many small, active catalyst particles instead of a few large, inactive ones. Such nucleation agencies can include auxiliary metal precursors that cluster more rapidly than the primary catalyst, or through provision of additional energy inputs (e.g., from a pulsed or CW laser) directed precisely at the region where cluster formation is desired. Under these conditions SWNTs nucleate and grow according to the Boudouard reaction. The SWNTs thus formed may be recovered directly or passed through a growth and annealing zone maintained at an elevated temperature (e.g., 1000° C.) in which tubes may continue to grow and coalesce into ropes.

A composite composition includes a plurality of carbon nanotube (CNT)-infused fibers dispersed in a matrix material. The amount of carbon nanotubes in the composition is in a range between about 0.1% percent by weight to about 60 percent by weight of the composite.

A carbon/carbon (C/C) composite includes a carbon matrix and a non-woven, carbon nanotube (CNT)-infused carbon fiber material. Where woven materials are employed, CNTs are infused on a parent carbon fiber material in a non-woven state. A C/C composite includes a barrier coating on the CNT-infused fiber material. An article is constructed from these (C/C) composites. A method of making a C/C composite includes winding a continuous CNT-infused carbon fiber about a template structure and forming a carbon matrix to provide an initial C/C composite or by dispersing chopped CNT-infused carbon fibers in a carbon matrix precursor to provide a mixture, placing the mixture in a mold, and forming a carbon matrix to provide an initial C/C composite.

Compositions comprising crosslinked graphene sheets and/or graphite oxide and having essentially no polymer binder and methods of making crosslinked graphene sheets and/or graphite oxide. The compositions can be made by crosslinking coatings comprising graphene sheets and/or graphite oxide.

The present application is directed to hard carbon materials. The hard carbon materials find utility in any number of electrical devices, for example, in lithium ion batteries. Methods for making the disclosed carbon materials are also disclosed.

The present invention relates to a metal nanocomposite powder reinforced with carbon nanotubes and to a process of producing a metal nanocomposite powder homogeneously reinforced with carbon nanotubes in a metal matrix powder.

Disclosed are an electron-emitting element having a large operating current at a low operating voltage and excellent operation stability, and an electron source, an image display device and the like utilizing such an electron-emitting element, and further a method of fabricating such an element with few process steps at low cost. A cold cathode member is configured utilizing hybrid particle of a first particle serving to emit electrons into the space and a second particle being in the vicinity of the first particle and serving to control the position of the first particle. In this configuration, it is preferable that the first particle have a higher electron emission efficiency than the second particle and that the second particle be conductive.

The present invention is to provide a method for carbonification of crop straws and a device thereof. Pyrolysis process is controlled by regulating the feeding of oxygen during said pyrolysis process, and pyrolysis and carbonification are respectively conducted in separate pyrolysis and carbonification pools, wherein the straws are pyrolyzed in said pyrolysis pool and entered into said carbonification pool to be carbonified. The present invention can quickly raise the temperature of the pyrolysis process, shorten the time of the pyrolysis process, and improve the pyrolysis carbonification efficiency.

The present invention discloses a nitrogen-doped porous carbon material preparation method, which comprises: adopting nitrogen-containing macromolecule as a template agent and a nitrogen source, adopting a biomass derivative as a carbon source, carrying out a hydrothermal carbonization reaction under a hydrothermal condition, and removing the template agent to obtain the nitrogen-doped porous carbon material. The present invention further provides a class of nitrogen-doped porous carbon materials prepared by using the method. The material obtained through the preparation method has characteristics of high nitrogen content and relatively high specific surface area. Experiment results show that the nitrogen-doped porous carbon materials provide excellent absorption performances for hydrogen and carbon dioxide. In addition, due to presence of the nitrogen-containing group, the porous material of the present invention can be expected to be used for catalysis, gas storage, molecule separation, clean energy carriers, super capacitors and other fields.

The invention relates to a method for preparing graphene crosslinked type organic aerogel and carbon aerogel by normal-pressure drying, which takes phenols (P), amines, aldehydes, catalyst and solvent as a reaction system and graphene substances containing active functional groups as a cross-linking agent. The method comprises the steps of: curing to obtain organogel, and then carrying out normal-pressure drying to obtain the organic aerogel; and carrying out pyrolysis on the organic aerogel in the inert atmosphere at the temperature of 500-1600 DEG C to obtain the graphene crosslinked type carbon aerogel. The preparation method of the organic aerogel and the carbon aerogel is simple and rapid in technology; the conventional supercritical drying technology is avoided, and the prepared novel organic aerogel and carbon aerogel materials taking graphene as framework have new performances and wide application prospect; and the industrial production of the carbon aerogel can be expected to be realized.

Powdered, amorphous carbon nanomaterials are formed from a carbon precursor in reverse microemulsion that includes organic solvent, surfactant and water. Methods for manufacturing amorphous, powdered carbon nanomaterials generally include steps of (1) forming a reverse microemulsion including at least one non-polar solvent, at least one surfactant, and at least one polar solvent, (2) adding at least one carbon precursor substance to the reverse microemulsion, (3) reacting the at least one carbon precursor substance so as to form an intermediate carbon nanomaterial, (4) separating the intermediate amorphous carbon nanomaterial from the reverse microemulsion, and (5) heating the intermediate amorphous carbon nanomaterial for a period of time so as to yield an amorphous, powdered carbon nanomaterial. Amorphous, powdered carbon nanomaterials manufactured according to the present disclosure typically have a surface area of at least 500 m²/g, a graphitic content of at least 25%, and a conductivity of at least 150 S/m.

The present invention relates to a method of functionalizing a carbon material. A carbon material is contacted with a carboxylic acid, whereby a mixture is formed. The mixture is heated for a suitable period of time at a temperature below the thermal decomposition temperature of the carbon material.

The present invention provides a bimodal porous carbon capsule with a hollow core and a mesoporous shell structure, which can be employed as an electrocatalyst support for a fuel cell; electrocatalysts for the fuel cell using the bimodal porous carbon capsule, and a method of preparing the same. The electrocatalyst according to the present invention has higher catalysis activity as compared with the Pt—Ru or Pt catalyst supported by the conventional carbon black, so that the performance of the fuel cell is enhanced, and it can be easily prepared in an aqueous solution state. According to the present invention, the porous carbon support employed as the support for the catalyst has excellent conductivity and a high surface area, so that the loaded catalyst can be prepared with a smaller amount than that of the conventional carbon black. Further, metal particles having an extremely fine size of 2˜3 nm are uniformly distributed on the support, so that the area of an active site at which catalysis reaction is performed is increased, thereby increasing the catalyst activity with respect to the oxidation reaction of the fuel such as methanol, ethanol, hydrogen, etc. Also, a fine pore of a porous carbon support secures a fuel dispersing passage, so that the fuel including alcohol such as methanol, ethanol or the like, hydrogen, etc. can be easily transferred and dispersed, thereby efficiently performing its oxidation-reduction reaction. On the other hand, an air electrode can efficiently function as the catalyst due to the same principle.

The invention belongs to the field of chemical engineering and industry, and particularly relates to a mesoporous-macroporous carbon production method. The production method comprises: completely mixing a phenol formaldehyde resin, an epoxy resin and the like or a mixture thereof, and a curing agent according to a certain weight ratio, carrying out heating curing, adding polyvinyl alcohol and the like as pore forming agents and adding graphite powder and the like as support agents after the cured material is crushed, completely mixing, pressing to form a preform, and carrying out high temperature carbonization under the protection of gas to obtain the mesoporous-macroporous carbon. The mesoporous-macroporous carbon prepared by using the production method has advantages of simple preparation method, easy pore size control and the like, wherein the pore size of the mesoporous-macroporous carbon can be adjusted within 50 nm-10 mum, has a specific surface area of 100-1000 m<2>/g, and can be used in electrode materials of supercapacitors, electrode materials of lithium ion batteries, electrode materials of capacitance method desalination devices, blood purification, catalyst carriers, water treatments, gas purification, solvent recovery and the like.

Silicon/carbon composite material, consisting of at least one capsule comprising a silicon shell within which there are carbon nano-objects partially or totally covered with silicon, and silicon nano-objects. The capsule may further comprise an amorphous carbon shell inside the silicon shell and adjacent to the latter. A method for preparing said composite material is disclosed.

The invention relates to a method for preparing biomass carbon by utilizing agricultural and forestry waste, belonging to the technical fields of preparation of carbon materials and utilization of biomass resources. The method comprises the following steps of: adopting agricultural and forestry waste as raw materials; under the condition of subcritical water, fully mixing dried biomass materials and deionized water according to the proportion of 1:(10-30); under the protection of inert atmosphere, carbonizing for 2-6 hours at the temperature of 220-250 DEG C; and then carrying out vacuum filtration and hot-water cleaning, and drying to obtain the biomass carbon. The biomass carbon prepared by the invention is coaly carbon material with an aromatic-ring structure, is high in carbon content and calorific value and large in specific surface area, and can be used as a soil conditioner or an absorbent. The method has the advantages that the materials are low in cost and easy to obtain, the process is simple, the operation is convenient, the manufacturing cost is low, the industrial promotion is convenient, and the application range and the application value of biomass resources are further expanded in the aspect of carbon materials.

In a method for storing hydrogen in a carbon material containing microstructures in the form of cones with cone angles being multiples of 60°, the carbon material is introduced in a reaction vessel which is evacuated while the carbon material is kept at a temperature of 295-800 K, after which pure hydrogen gas is introduced in the reaction vessel, the carbon material being exposed to a hydrogen gas pressure in the range of 300-7600 torr such that the hydrogen gas is absorbed in the carbon material, and after which the reaction vessel is left at the ambient temperature with the carbon material under a fixed hydrogen gas pressure. For use the hydrogen is released in the form of a gas from the carbon material either at ambient temperature or by heating the carbon material in the reaction vessel. In a method for refining a carbon material of this kind for hydrogen storage, the carbon material is produced in a reaction chamber with the use of a catalyst for adjusting the cone angle distribution of the microstructures. Use for storing of hydrogen as fuel for powering transport means, including vehicles.

Carbon powder having low temperature calcined carbon derived from pitch adhered to a portion of the surface of natural graphite powder is obtained by solids mixing of natural graphite powder and pitch powder as a carbon precursor followed by heat treatment at 900-1500° C. to carbonize the pitch. The amount of pitch powder is such that the ratio V2/V1 of the pore volume V2 of pores having a diameter of 50-200 nm to the pore volume V1 of pores having a diameter of 2-50 nm in a pore size distribution curve obtained by analysis of the nitrogen desorption isotherm of the resulting carbon powder by the BJH method is at least 1. This carbon powder can be used as a negative electrode material for a nonaqueous secondary battery able to operate at low temperatures.

To deal with climate change, the present invention provides an eco-engineering for systematic carbon mitigation, in particular, a comprehensive carbon management system with a group of Stabilized Functional Carbons (SFCs) to reduce the total amount of carbons in atmosphere. SFCs are sourced and manufactured from the carbon-fixed biomass by one of the seven thermo-chemical treatments or one dehydration treatment with no less than 75% carbon conversion rates of the source material. The present invention transforms the perishable biomass into SFCs, which act as a carbon sink with stability and safety for at least 40 years' storage. The primary eco-friendly carbon and non-carbon mitigation are achieved by the sourcing, manufacturing and storage of SFCs. The advanced eco-friendly carbon and non-carbon mitigation are achieved at various pollution emission sources by the resource utilization of SFCs. An annual total amount of 0.5-10 billion tons of carbon emission could be reduced globally.

The invention provides fluorinated multi-layered carbon nanomaterials and methods for their production. In one aspect of the invention, the carbon nanomaterials are partially fluorinated and retain some unreacted carbon. The invention also provides electrodes and electrochemical devices incorporating the fluorinated carbon nanomaterials of the invention. In one aspect of the invention, the electrochemical has a first electrode including the at least partially fluorinated carbon materials of the invention and a second electrode including a source of lithium ions

The present invention relates to a novel carbon nano-particle and a novel method of preparing the same and a transparent, conductive polymer composite containing the same. The carbon nano-particle has the mean diameter of 1 through 50 nm and the shape of sphere, rod or others, which is a novel material not known in the relevant art. Because of a particle size less than ½ of the shortest wavelength of a visible ray, a transparent resin containing the carbon nano-particle can maintain the transparency. Furthermore, the carbon nano-particle has the excellent electric conductivity and the ferromagnetic property, and can be made by a novel, low cost method entirely different from those of fullerene and carbon nanotube.

The invention relates to an application of a porous carbon material with a grading pore structure in a lithium-air cell anode, and is characterized in that the carbon material has mutually communicated grading pore structure distribution which has a mesoporous structure for depositing the discharge products and a macroporous structure suitable for transmission of oxygen and an electrolyte. When the carbon material is taken as a material of the lithium-air cell anode, the space utilization rate of carbon material can be increased at maximum limitation during a charge and discharge process, specific discharge capacity, voltage platform and multiplying power discharge capability of the cell can be effectively increased, so that the energy density and power density of the lithium-air cell can be increased. The porous carbon material has the advantages that the preparation technology is simple, the material source is wide, the grading pore carbon material pore structure enables regulation and control, the regulation and control modes are various, and the doping of metal/metal oxide can be easily and simultaneously realized.