710 results about "Multiwalled carbon" patented technology

Methods of oxidizing multiwalled carbon nanotubes are provided. The multiwalled carbon nanotubes are oxidized by contacting the carbon nanotubes with gas-phase oxidizing agents such as CO₂, O₂, steam, N₂O, NO, NO₂, O₃, and ClO₂. Near critical and supercritical water can also be used as oxidizing agents. The multiwalled carbon nanotubes oxidized according to methods of the invention can be used to prepare rigid porous structures which can be utilized to form electrodes for fabrication of improved electrochemical capacitors.

The invention discloses a magnetic carbon nanotube composite material and a preparation method and an application thereof. The preparation method comprises the following steps: adding FeCl3.6H2O to an ethylene glycol solution; then adding anhydrous sodium acetate and polyethylene glycol; adding a carboxylated multiwalled carbon nanotube; performing ultrasonic dispersion; adding hexamethylenediamine or ethanediamine; heating to 200-300 DEG C for reaction for 8-24h; and washing and performing vacuum drying to prepare the amino-modified magnetic Fe3O4-carbon nanotube composite material. The amino-modified magnetic Fe3O4-carbon nanotube composite material prepared by the invention is of nanoscale and superparamagnetism, can be stably dispersed in solutions, and can be quickly separated and enriched through a simple action of a magnetic field. As an adsorbent, the material is large in superficial area and has various active groups on the surface. The material can adsorb pigments from complex substrates through pi-pi electron interaction and hydrophobic effect of the carbon nanotube and can adsorb compounds such as organic acids and phenols through weak anion exchange effect of amino groups on the surfaces of magnetic nanoparticles.

A heat exchanger with mini channels or micro channels provides enhanced heat transfer abilities. One or more surfaces of the channels may be covered with a nanostructure, such as single walled carbon nanotubes or multiwalled carbon nanotubes. The nanostructures may fully cover the entire surface of the channel or a selected surface area of the channel. Further, the nanostructures may be arranged into multiple patterned bundles covering the surface of the channel.

The invention discloses a high heat conducting nylon composite material and a preparation method thereof. The high heat conducting nylon composite material belongs to one of functional high molecules. The composite material is prepared from a thermoplastic nylon resin base body, heat conducting filler and other processing agents. The heat conducting coefficient is greater than 2.7W/m.K. The resin base body can be nylon 6 or a compound of nylon 6, nylon 9, nylon 66, nylon 610 and nylon 1010. The heat conducting filler can be one or more of magnesium oxide, aluminum oxide, aluminum nitride, boron nitride, silicon nitride, a multiwalled carbon nanotube and a graphite flake layer. The processing agents can be octadecanamide, polyethylene wax, liquid paraffin and the like. The method disclosed by the invention is simple to operate and low in cost, and can prepare the heat conducting composite material with excellent comprehensive performance by one step. The method is easy to realize industrialized production and can be widely applied to the fields of automobiles, household appliances, meter cases, circuit elements and the like.

The invention relates to a flexible symmetrical pseudocapacitance super capacitor and a preparation method thereof. The flexible symmetrical pseudocapacitance super capacitor comprises a positive electrode, a negative electrode and electrolyte, wherein the electrolyte is arranged between the positive electrode and the negative electrode; the flexible symmetrical pseudocapacitance super capacitor is characterized in that with a nano nickel particle/multiwalled carbon nanotube/conductive carbon cloth electrode employing conductive carbon cloth as a current collector and a nano nickel particle/multiwalled carbon nanotube as an active material as the positive electrode and the negative electrode, the flexible symmetrical pseudocapacitance super capacitor is formed by growing the nano nickel particle on a multiwalled carbon nanotube/conductive carbon cloth base; and the nano nickel particle and the multiwalled carbon nanotube are combined in situ. The nano nickel particle/multiwalled carbon nanotube/conductive carbon cloth electrode has the advantages of high global electronic mobility and excellent rate capability; the pseudocapacitance super capacitor assembled by the nano nickel particle/multiwalled carbon nanotube/conductive carbon cloth electrode has a symmetrical structure, and is capable of charging and discharging in positive and negative directions without distinguishing of the polarity; compared with a traditional carbon-based super capacitor, relatively high specific capacity of pseudocapacitance can be provided; and the flexible symmetrical pseudocapacitance super capacitor has excellent mechanical flexibility.

The invention relates to a lamellar fibre material and a preparation method thereof. The lamellar carbon nanofibre has multiple layers and a fibre structure of various cross-sectional shapes. The carbon nanofibre structure in the fibre is single-wall carbon nanotube, double-wall carbon nanotube and multi-wall carbon nanotube or a lamination carbon nanotube formed by the collapse of the carbon nanotubes. The macro structure of the fibre is hollow, solid, flat or crimp, and the like. Reaction carbon source, catalyst and promoter are mixed and added into high-temperature reaction airflow of a reactor, carbon nanotube for catalytic cracking growth is gathered into aggregate of lamellar carbon nanotube fibre in the reaction airflow, and the aggregate is spinned after liquid action or spinned through other online processing. The fibre with a multi-layer structure can be applied to structures, functional devices, knitting, and the like. The preparation method of the invention has simple process, is stable and reliable and can be used for preparing various multi-layer carbon nanofibre materials in industries.

An open-cell carbon nanotube foam is made of a plurality of separated carbon nanotubes. The foam exhibits a Poisson's ratio substantially equal to zero, a compressibility of at least 85%, a recovery rate of at least 120 mm/min, a compressive strength of at least 12 MPa, a sag factor of at least 4, a fatigue resistance to no more than 15% permanent deformation when subjected to at least 1,000 compressive cycles at a strain of 85%, and/or a resilience of between 25% and 30%. The carbon nanotubes may be multiwalled carbon nanotubes that are aligned parallel to a thickness of a film comprising the foam.

Methods of treating single walled and multiwalled carbon nanotubes with ozone are provided. The carbon nanotubes are treated by contacting the carbon nanotubes with ozone at a temperature range between 0° C. and 100° C. to yield functionalized nanotubes which are greater in weight than the untreated carbon nanotubes. The carbon nanotubes treated according to methods of the invention can be used to prepare complex structures such as three dimensional networks or rigid porous structures which can be utilized to form electrodes for fabrication of improved electrochemical capacitors. Useful catalyst supports are prepared by contacting carbon nanotube structures such as carbon nanotube aggregates, three dimensional networks or rigid porous structures with ozone in the temperature range between 0° C. and 100° C.

Methods of preparing conductive thermoset precursors containing carbon nanotubes is provided. Also provided is a method of preparing conductive thermosets containing carbon nanotubes. The carbon nanotubes may in individual form or in the form of aggregates having a macromorpology resembling the shape of a cotton candy, bird nest, combed yarn or open net. Preferred multiwalled carbon nanotubes have diameters no greater than 1 micron and preferred single walled carbon nanotubes have diameters less than 5 nm. Carbon nanotubes may be adequately dispersed in a thermoset precursor by using a extrusion process generally reserved for thermoplastics. The thermoset precursor may be a precursor for epoxy, phenolic, polyimide, urethane, polyester, vinyl ester or silicone. A preferred thermoset precursor is a bisphenol A derivative.

The invention relates to preparation and application of a magnetic ferroferric oxide nanoparticle modified carbon nanotube composite material. The preparation method includes: mixing a divalent iron salt and a trivalent iron salt, adding NH3.H2O, conducting water bath and centrifugal separation, washing the precipitate, and carrying out drying and grinding to obtain magnetic Fe3O4 nanoparticles; adding concentrated nitric acid and concentrated sulfuric acid into pretreated carbon nanotubes, conducting heating refluxing, carrying out filtering, deionized water washing and vacuum drying, thus obtaining purified multiwalled carbon nanotubes; adding the purified multiwalled carbon nanotubes into a triethylene glycol solution, conducting ultrasonic treatment, adding magnetic Fe3O4 nanoparticles, performing stirring and heating, conducting heat preservation and cooling, separating the product, and conducting vacuum drying, thus obtaining the magnetic Fe3O4 nanoparticle modified carbon nanotube composite material. The composite material is used for detecting the residue amount of organophosphorus pesticides in food. The preparation method utilizes magnetic Fe3O4 nanoparticles to modify carbon nanotubes, and greatly improves the dispersibility and adsorption properties of carbon nanotubes in water. The prepared magnetic Fe3O4 nanoparticle modified carbon nanotube composite material hasgood stability, and the maximum recovery rate can reach 89.6%.

Disclosed high-performance concrete comprises the following compositions in parts by weight: 100-140 parts of cement, 500-700 parts of broken stone, 100-180 parts of river sand, 30-60 parts of fly ash, 20-50 parts of mineral slag, 50-90 parts of silica fume, 10-30 parts of limestone powder, 20-50 parts of basalt fiber, 30-80 parts of straw powder, 2-6 parts of a water reducer, 20-80 parts of nanometer silicon dioxide, 5-15 parts of nanometer calcium carbonate, 5-30 parts of multiwalled carbon nanotube, 1-3 parts of sodium dodecyl sulfate, 3-6 parts of zine stearate, 2-5 parts of boric acid, 3-7 parts of sodium citrate, and 80-100 parts of water. The high-performance concrete is high in strength, good in impermeability and good in endurance.

The invention provides a preparation method and application of a graphene/carbon nano-tube composite. The preparation method comprises the following steps: oxidizing graphene powder and a multiwalled carbon nano-tube together to obtain graphene oxide and an oxidized carbon nano-tube; carrying out ultrasonic peeling and dispersion on the graphene oxide and the oxidized carbon nano-tube; carrying out modification connection and reduction on the graphene oxide and the oxidized carbon nano-tube with ammonia water and ethylenediamine; and filtering, washing and drying a product after reaction to obtain the graphene/carbon nano-tube composite. The preparation method is simple and convenient, and reaction conditions are mild; in the preparation method, the graphene is connected with the carbon nano-tube through covalent modification, and the carbon nano-tube is connected between graphene slice layers. The graphene/carbon nano-tube composite prepared by the method has a fluffy and porous three-dimensional skeleton structure, and can be used for extracting and detecting melamine, clenbuterol, sulfadimidine sodium, indoleacetic acid, bambuterol, clorprenaline, dicofol, 2,2-bis(4-chlorophenyl)-1,1-dichloroethane or chlorofluoro thiochromanone.

The invention discloses a multiwalled carbon nanotube and graphene reinforced modified regenerated protein fiber and a preparation method thereof. The modified regenerated protein fiber is prepared from protein, a surfactant, a functionalized carbon nano tube and/or functionalized graphene, wherein the mass fraction of the protein is more than or equal to 53wt%; the functionalized graphene is any one of carboxylated graphene, aminated graphene, hydroxylated graphene and polar polymer grafted graphene; the functionalized multiwalled carbon nanotube is any one of carboxylated multiwalled carbon nanotube, aminated multiwalled carbon nanotube, hydroxylated multiwalled carbon nanotube and polar polymer grafted multiwalled carbon nanotube. The preparation method of the regenerated protein fiber comprises the steps of curing raw materials and then spinning. The preparation method is simple, the prepared product has good physical and mechanical properties, and the original performances of the protein fiber can be remained.

The invention relates to a supercapacitor electrode material molybdenum sulfide-multiwalled carbon nanotube and a preparation method of the supercapacitor electrode material molybdenum sulfide-multiwalled carbon nanotube. The preparation method includes the steps that MWCNTs is added to redistilled water and ultrasonically dispersed; Na2MoO4 2H2O is added, after even dispersion, the pH value of the solution is set to 6.5, L-cysteine is added, and the solution is diluted to 80mL by redistilled water and stirred vigorously for an hour; hydrothermal reaction is conducted on the mixture at the reaction temperature ranging from 160 DEG C to 200 DEG C for 48-50 hours; after the reaction, the mixture is naturally cooled to be at the indoor temperature, centrifuged, washed and dried, and then a molybdenum sulfide-multiwalled carbon nanotube composite material is acquired; the molybdenum sulfide-multiwalled carbon nanotube composite material is evenly mixed with carbon black and polytetrafluoroethylene, the surface of a stainless steel wire screen is evenly coated with the mixture, and a composite electrode material is prepared after vacuum drying. The prepared composite material combines the advantages of molybdenum sulfide with the advantages of the multiwalled carbon nanotube, specific capacitance and electrochemical stability are improved, and the composite material is a good supercapacitor material; the preparation method is easy and quick to implement and environmentally friendly, and the composite material prepared through the preparation method is low in cost.

The invention provides a preparation method for nickel-oxide/ reduced-graphene-oxide nanosheet composite materials. The preparation method includes using multiwalled carbon nanotubes as raw materials and adopting the Hummer method to obtain graphene-oxide nanosheets with lamellar structures and easy to disperse through oxidation; ultrasonically dispersing the grapheme oxide nanosheets and Ni (NO3)2 6H2O in ethyl-alcohol solvent to perform solvent thermal reaction at the temperature of 140-180 DEG C for 10-12 hours; after the temperature is cooled to room temperature, filtering, washing with water and absolute ethyl alcohol and drying in vacuum to obtain precursor composite materials; preforming thermal treatment on the precursor composite materials under air atmosphere and at the temperature of 200-250 DEG C for 3-5 hours to obtain the nickel-oxide/ reduced-graphene-oxide nanosheet composite materials. The composite materials prepared by the method integrate the characteristics of NiO and rCNGO, and are enabled to have better electrochemistry performance as compared with homogenous materials through synergistic effects among components, thereby being capable of serving as electrode materials of super capacitors.

The invention relates to a preparation method for a carbon nanotube super-hydrophobic coating. The preparation method comprises the following steps: after pickling a substrate to remove surface oxides, successively ultrasonically cleaning the substrate for 15min with acetone, anhydrous ethanol and deionized water to remove surface oil stains and dust and drying the substrate with cold air for later use; ultrasonically dispersing multiwalled carbon nanotubes containing hydroxyl in an isopropanol solution, and adding ammonia water and deionized water drop by drop; after uniformly stirring the solution, adding tetraethoxysilane; after a reaction for a period of time, dropwise adding a silane solution and continuously stirring the mixture; finally obtaining a carbon nanotube super-hydrophobic coating solution; and spraying the carbon nanotube super-hydrophobic coating solution to the substrate, and drying the substrate to obtain the carbon nanotube super-hydrophobic coating. The super-hydrophobic coating with low adhesive ability has the characteristics of being self-cleaned and resisting pollution, condensation and frosting. The preparation method provided by the invention is simple in preparation process and low in cost, can realize large scale production, and has a wide application prospect and a huge market benefit in the aspects of condensing heat transfer, sea water desalination, air source heat pump and the like.

A method for forming a pattern of carbon nanotubes includes forming a pattern on a surface-treated substrate using a photolithographic process, and laminating carbon nanotubes thereon using a chemical self-assembly process so as to form the carbon nanotubes in a monolayer or multilayer structure. A monolayer or multilayer carbon nanotube pattern may be easily formed on the substrate, e.g., glass, a silicon wafer and a plastic. Accordingly, the method can be applied to form patterned carbon nanotube layers having a high conductivity, and thus will be usefully utilized in the manufacturing processes of energy storages, for example, solar cells and batteries, flat panel displays, transistors, chemical and biological sensors, semiconductor devices and the like.

The invention relates to a preparation method of a urethane elastic fiber with a function of resisting electromagnetic radiation. The preparation method comprises the following steps: sequentially adding dimethylacetamide and polytetramethylene ether glycol into a pre-polymerizing tank; then, precisely adding 4, 4-diphenylmethane diisocyanate in a certain proportion of NCO/OH; heating to a set temperature and carrying out pre-polymerization reaction; after reaching the predetermined reaction time, adding diluting dimethylacetamide into the pre-polymerizing tank and stirring for a period of time; transferring pre-polymer liquor to a chain extending tank; cooling the pre-polymer liquor in the chain extending tank to about 10 DEG C through a refrigerant; then, slowly adding chain extending amine liquor; judging the terminal point of the reaction according to a current curve of a stirring motor; after chain extension, adding various additives such as a multiwalled carbon nanotube, an anti-yellowing assistant, an ultraviolet light resistant absorber, an antioxidant, a lubricant and a delustering agent; and preparing the urethane elastic fiber by polymerizing original liquor through dry spinning.

The invention belongs to the field of electrochemistry and discloses multiwalled carbon nanotube/sulphur/polyaniline composite cathode material, a preparation method thereof, and the application thereof to the preparation of lithium sulphur batterypositive plates. The material adopts multiwalled carbon nanotube/sulphur/polyaniline composite cathode material and a sandwich structure; multiwalled carbon nanotube/sulphur composite material is coated with conductive polyaniline through in-situ polymerization, so that the multiwalled carbon nanotube/sulphur/polyaniline composite cathode material is formed; the multiwalled carbon nanotube/sulphur composite material is prepared through chemical co-deposition. The method is simple in technology, low in cost and high in consistency and stability of products. The material is high in electronic and ionic conductivity and high in sulphur carrying capacity, and can be applied to the preparation of lithium battery composite positive plates; the positive plate is high in cycling stability and capacity retention ratio.

The invention discloses a fireproof coating with high-temperature resistance and a preparation method of the fireproof coating. The fireproof coating with high-temperature resistance is prepared fromcomponents in parts by mass as follows: 50-75 parts of an aqueous film forming matrix, 8-15 parts of multiwalled carbon nanotubes, 0.3-1 part of graphene oxide, 0.9-1.5 parts of modified nano hollow silicon dioxide pellets, 30-40 parts of a composite expansion type flame retardant, 14-20 parts of melamine, 12-18 parts of pentaerythritol, 0-9 parts of potassium silicate, 6-12 parts of bentonite, 0.5-2.5 parts of an auxiliary and 40-60 parts of water. With the adoption of compounding of the multiwalled carbon nanotubes, graphene oxide and the modified nano hollow silicon dioxide pellets, the flame retardant effect of the fireproof coating can be improved synergistically, and production of volatile degradation products is inhibited. The fireproof coating with high-temperature resistance has excellent high-temperature resistance, a coating layer avoids blistering, cracking and peeling under the high temperature condition, and the service life of a component can be prolonged effectively.

Disclosed is a device whereby the thermal conductance of a multiwalled nanostructure such as a multiwalled carbon nanotube (MWCNT) can be controllably and reversibly tuned by sliding one or more outer shells with respect to the inner core. As one example, the thermal conductance of an MWCNT dropped to 15% of the original value after extending the length of the MWCNT by 190 nm. The thermal conductivity returned when the tube was contracted. The device may comprise numbers of multiwalled nanotubes or other graphitic layers connected to a heat source and a heat drain and various means for tuning the overall thermal conductance for applications in structure heat management, heat flow in nanoscale or microscale devices and thermal logic devices.

The invention relates to an amino-containing crosslinkable polyether sulfone and a preparation method thereof and applications of a gas separation membrane, belonging to the field of a polymer nanocomposite material. Aiming at solving the problems of compatibility of gas permeability and separating property of the existing gas separation membrane, a membrane formed mixing and casting crosslinkable polyether sulfone with molecular side chain containing phenylamino and allyl, together with pyrrolidone, or a thermal-crosslinked membrane is formed by adding benzoyl peroxide in mixing with N-methyl pyrrolidone and casting can be utilized, in addition, a mixed matrix membrane or mixed matrix thermal-crosslinked membrane can formed by adding a multiwalled carbon nanotube. The amino containing can have hydrogen bond interaction with carboxyl of the carbon nanotube, the carbon nanotube can be more evenly dispersed in polymer, and the two interfaces have good binding power, so that the gas permeability and selectivity of the mixed matrix membrane can be enhanced. The amino-containing crosslinkable polyether sulfone is used for preparing the gas separation membrane and gas separation.