361 results about "Carbon nanosphere" patented technology

The invention discovers and proposes a characteristic that interior species of phenolic resin are nonuniform in distribution in a polymerization process, and discloses a method for preparing a hollow carbon sphere by utilizing the characteristic of phenolic resin. The method comprises: (1) putting phenol into water or a solvent, adjusting the pH, then adding aldehyde and stirring at a certain temperature for a period of time; (2) adding a corrosive agent in a reaction system, stirring at a certain temperature, and selectively removing a part with a relatively low polymerization degree inside a polymer by utilizing a solubility difference of interior species for different solvents, to obtain an intermediate product, that is, a hollow sphere of phenolic resin polymer; and (3) calcining the intermediate product that is obtained in step (2) in an inertia or reducing atmosphere, naturally cooling to room temperature, and thus completing preparation of the hollow carbon sphere. The method is simple and practicable, and the prepared hollow carbon sphere is uniform in shape and controllable in dimension. Moreover, by utilizing a characteristic that the phenolic resin can be in-situ polymerized on surfaces of different nanometer particles, on one hand, a multi-layer hollow structure can be prepared in a multi-cladding and layer-by-layer corrosion manner, and on the other hand, the different nanometer particles can also be packaged in a cavity in an in-situ mode, so as to prepare a nuclear shell or egg yolk-nuclear structure. The prepared hollow carbon sphere has a potential application value in aspects of silicon-carbon negative electrode material, Li-S battery, supercapacitor, heavy metal ion adsorption, and the like.

A carbon nanosphere has at least one opening. The carbon nanosphere is obtained by preparing a carbon nanosphere and treating it with an acid to form the opening. The carbon nanosphere with at least one opening has higher utilization of a surface area and electrical conductivity and lower mass transfer resistance than a conventional carbon nanotube, thus allowing for higher current density and cell voltage with a smaller amount of metal catalyst per unit area of a fuel cell electrode.

The invention relates to the technical field of nano material preparation, in particular to a method for preparing ZnO/ZnFe2O4 compound nano hollow spheres. The method comprises the following steps of: (1) preparing a water solution of glucide compound; (2) placing the prepared water solution of glucide compound into a reaction container; (3) sealing the reaction container containing the prepared water solution of a glucide compound, after the heating, the reaction and the cooling of the sealed container, conduct centrifugal separation to obtain a product, washing the product with distilled water and absolute ethyl alcohol, and drying the washed product to obtain carbon spheres with the diameter of 200 nm to 4 mu m; (4) preparing an alcoholic solution containing the carbon spheres; (5) after the reaction of the prepared alcoholic solution containing the carbon spheres, conducting cooling and centrifugal separation to obtain carbon nano spheres cladded with metal hydroxides; (6) calcining the obtained arbon nano spheres clad with metal hydroxides to obtain the ZnO/ZnFe2O4 compound nano hollow spheres. The invention has the characteristics of simple operation and low technological requirements.

The invention discloses a preparation method for hollow carbon nanospheres, comprising: 1) placing a phenol in water, adjusting the pH value, adding an aldehyde, and stirring the solution at a certain temperature for a period of time; 2) adding an etchant to the reaction system and performing stirring at a certain temperature to obtain an intermediate product through selective removal of parts with low polymeric properties in the polymer by using the solubility difference between internal substances for different solvents; 3) calcining, in an inert or a reducing atmosphere, the intermediate product obtained in Step 2), and cooling the substance, thereby completing preparation of the hollow carbon nanospheres. In addition, by using the property that the phenolic resin is capable of in-situ polymerization on different nanoparticle surface, on one hand, a multi-layer hollow structure can be made through multiple times of coating and layer-by-layer corrosion; and on the other hand, different nanoparticles can be in-situ packaged in a cavity, thereby making a core-shell or yolk-core structure.

The invention provides a high-performance silicon/carbon anode nanocomposite and a preparation method thereof. The high-performance silicon/carbon anode nanocomposite is characterized by containing carbon nano-spherical particles with mesoporous channels, and the spherical particles and/or the mesoporous channels are filled with elementary silicon particles. The prepared silicon/carbon anode nanocomposite is of a porous structure, the elementary silicon particles are dispersed in a carbon skeleton and the mesoporous channels, the volume expansion effect during lithium-ion charge and dischargeis low, and electrochemical cycle performance is stable.

The invention relates to a preparation method of a hollow silicon dioxide nanomaterial. According to the preparation method, with carbon nanospheres as a hard template, tetraethoxysilane (TEOS) as a silicon source, water as a solvent and cetyl trimethyl ammonium bromide (CTAB) as a structure-directing agent, the hollow SiO2 nanomaterial which is even in appearance and folded in surface can be formed after residual organic matters such as carbon spheres and CTAB are removed by use of subsequent heat treatment. A TEM picture indicates that the SiO2 nanomaterial prepared by use of the method has a hollow structure and is about 20 nanometers in wall thickness and about 200 nanometers in grain size. The hollow SiO2 nanomaterial prepared by use of the method has potential application prospect in the fields such as biomedicine.

A high yield method for chemically synthesizing low polydispersivity carbon microspheres, nanospheres, nanocrystals, nanotubes, or nanofibers comprising dispersing a self-polymerizing end-capped polyyne in a solvent; heating the dispersed self-polymerizing end-capped tetrayne to form a polymeric material selected from the group consisting of polymer microspheres, polymer nanospheres, polymer nanocrystals, polymer nanotubes, and polymer nanofibers; and pyrolyzing the polymeric material to form a carbon material selected from the group consisting of carbon microspheres, carbon nanospheres, carbon nanocrystals carbon nanotubes, and carbon nanofibers, wherein the polydispersivity is less than 2.

A preparation method and an application of a graphene @ metal phosphide @ carbon nano composite material. The invention relates to preparation methods and applications of a graphene composite material and aims to solve the problems that metal phosphides in the prior art are poor and low in electric conductivity, are poor in reaction reversibility, and are liable to agglomerate and expand. The preparation method includes the steps of: 1) preparing metal oxide nanospheres; 2) preparing metal oxide @ carbon nanospheres; 3) preparing metal phosphite @ carbon nanospheres; and 4) performing high-temperature carbonization to prepare the graphene @ metal phosphide @ carbon nano composite material. The composite material is used as an anode material in lithium ion batteries or sodium ion batteries. The specific capacity of a CR 2025 button lithium ion battery, which is produced with the nano composite material as an anode material, is still higher than 1000 mAh/g after cycle for three times under current density of 0.2 A/g; and after cycle for 100 times, the specific discharge capacity of the battery is still higher than 700 mAh/g.

The invention discloses electrostatic spinning liquid for silicon dioxide fibers and a method for preparing porous silica dioxide fibers by utilizing an electrospinning method. The electrostatic spinning liquid is composed of silica dioxide sol, polyvingakohol, a pore-forming agent and the like. The pore-forming agent is the mixture composed of one of or two of carbon nanospheres, polymethyl methacrylate nanospheres, polystyrene nanospheres. Through electrospinning, silicon dioxide/pore-forming agents/polyvingakohol composite fibers are obtained. Through high-temperature calcination, pore-forming agents and polyvingakohol can be oxidized and decomposed. Therefore, porous silica dioxide fiber structure is obtained by the above preparation steps. The porous silica dioxide fibers obtained by preparation are featured by being resistant to high temperature and corrosion. Meanwhile, the porous silica dioxide fibers are soft, highly endurable, which can be used for multiple environments such as acid or alkali and can also be used for surface absorption and separation, absorption of catalyst carriers and ions and sewage treatment and the like.

The invention relates to a high-energy-density carbon nano-sphere/NiCo2O4 composite material of a lithium ion battery and a super-capacitor as well as a preparation method and application of the composite material. The nano-sphere/NiCo2O4 composite material is a core-shell structure nano sphere with the grain diameter of 100-300nm; and the inner layer of the nano-sphere/NiCo2O4 composite material is a carbon nano sphere with the grain diameter of 50-200nm and the outer layer of the nano-sphere/NiCo2O4 composite material is a NiCo2O4 coating layer with the thickness of 20-100nm. The preparation method comprises the following steps: mixing the carbon nano sphere with the grain diameter of 50-200nm with sodium oleate and uniformly dispersing by ultrasounds; then adding weak alkali, Co<2+> and Ni<2+>; and uniformly mixing, then carrying out hydrothermal treatment to obtain the carbon nano-sphere/NiCo2O4 composite material with the core-shell structure. The method has the advantages of simplicity in operation, environment friendliness, wide raw material resource, low production cost and the like, and is suitable for large-scale production and preparation. The first-time discharge capacity of a lithium ion battery negative electrode material prepared from the material can reach 1600mAh/g. The material is used as a super-capacitor electrode material and has the specific capacitance being up to 1420F/g (1A/g).

The invention relates to a preparation method of a gold/nitrogen-doped hollow carbon nanosphere core-shell material, belonging to the field of biomedical materials. The preparation method comprises the steps of firstly, preparing gold sol by using a sol-gel method; secondly, coating the surfaces of gold particles with SiO2 by using an improved stober method, and then forming Au@SiO2@PDA spheres in a weak alkaline water-containing environment by means of auto polymerization of dopamine; finally, carrying out high-temperature calcination, and obtaining the gold/nitrogen-doped hollow carbon nanosphere core-shell material after NaOH is etched. The method is simple, mild and environment-friendly, and does not add additional toxicity; the prepared gold/nitrogen-doped hollow carbon nanosphere core-shell material has the particle size of about 165-175nm; as a near-infrared photothermal therapeutic agent for treating tumors, a product not only has good biocompatibility and light and heat stability, but also has the characteristic of having an internal hollow structure; after the gold/nitrogen-doped hollow carbon nanosphere core-shell material is used, the speed of particle exchange is accelerated, and the photothermal conversion efficiency is improved.

The invention discloses a yolk-eggshell structure Au@ hollow carbon nanosphere composite material and preparation and application thereof. A preparation method includes the following steps that sodium citrate is adopted for reducing chlorogoldacid, and nanogold hydrosol is prepared; the nanogold hydrosol, organic monomers, water and a Triton X-100 aqueous solution are stirred and mixed; then, an initiating agent is added into a system to initiate polymerization of the monomers, and precursors are prepared; the organic monomers are composed of aniline and pyrrole; and under the inert atmosphere, the precursors are processed in a high-temperature carbonizing manner so that the yolk-eggshell structure Au@ hollow carbon nanosphere composite material can be prepared. According to the preparation method, the tedious steps that a template is prepared, complicated surface modification is needed and the template is removed are not needed, and preparation is easy and convenient. The specific surface area and the size of the prepared material can be regulated and controlled through the carbonization condition and the concentration of the organic monomers, the specific surface area is high, and the prepared material has a good catalytic effect on nitrobenzene and p-nitrophenol.

The invention discloses a preparation method of hollow carbon nanospheres with MOFs (metal-organic frameworks) formed through limited-range growth inside and belongs to the technical field of nanomaterial production. Tetraethyl orthosilicate, ethanol, deionized water, ammonium hydroxide, resorcinol and methanol are mixed for a reaction, SiO2@resorcinol-formaldehyde resin microspheres are obtained and calcined in argon, SiO2@C nanospheres with a core-shell structure are obtained and dispersed in a sodium hydroxide water solution to be etched, and mesoporous hollow carbon nanospheres are obtained; finally, the mesoporous hollow carbon nanospheres are dispersed in methanol, metallic nitrates and 2-methylimidazole are added for a reaction, and the hollow carbon nanospheres with MOFs formed through limited-range growth inside are obtained. Equipment used in the method is simple, the method is low in cost and simple in operation process, materials required in the reaction process are low in toxicity and harmless, the stoichiometric ratio of multi-component materials can be effectively controlled, and the obtained products are uniform in size, uniformly distributed and are good in morphological control.

The present invention provides a point, line, surface three-dimensional carbon material composite heat-conduction silica gel and a preparation method thereof. The composite heat-conduction silica gel comprises, by weight, 0.1-30% of surface-modified graphene, 0.1-30% of surface-modified carbon nano-tubes, 0.1-30% of surface-modified carbon nano-spheres, and the balance of silica gel, wherein the sum of the mass fractions of the surface-modified graphene, the surface-modified carbon nano-tubes and the surface-modified carbon nano-spheres is more than or equal to 10%, a mass ratio of the surface-modified graphene to the surface-modified carbon nano-tubes to the surface-modified carbon nano-spheres is 1:0.5-2:0.5-4, and the surface-modified graphene, the surface-modified carbon nano-tubes and the surface-modified carbon nano-spheres are prepared through treatment modification with strong acids. According to the present invention, the solubilities and the dispersions of the graphene, the carbon nano-tubes and the carbon nano-spheres in the silica gel are effectively improved, and the three modified carbon materials form the stable and continuous three-dimensional heat-conduction network in the silica gel so as to substantially improve the thermal conductivity of the heat-conduction silica gel.

The method for preparing carbon nanosphere by using coal base carbon rod or graphitic rod as electrode and adopting plasmka arc discharge technology under the condition of helium gas/acetylene gas atmosphere is characterized by that said method includes the following steps: making raw material coal undergo the process of pretreatment to obtain carbon rod which is uniform in size and quality and has proper electric conductivity; using said carbon rod or graphite rod as anode and placing it into DC arc plasma equipment to make discharge evaporation under the condition of helium gas/acetylene gas atmosphere, after discharge, collecting black beard-like material grown out on the top of anode in the reaction process so as to obtain the invented carbon nanosphere. Said invention also provides its application range.

Process for producing carbon nanospheres and other nano materials with carbon dioxide and magnesium. The carbon dioxide and magnesium are combusted together in a reactor to produce carbon nanospheres and magnesium oxide, which are then separated to provide the individual reaction products. The reaction occurs at a very high temperature, e.g. 2000° F.-5000° F. and also produces large amounts of useful energy in the form of heat and light, including infrared and ultraviolet radiation. Other oxidizing agents such as aluminum can be combined with the magnesium, and the metal oxides produced by the reaction can be recycled to provide additional oxidizing agents for combustion with the carbon dioxide. By varying the reaction temperature, the morphology of the carbon products can be controlled.

The invention relates to a preparation method of a molecularly imprinted composite membrane material, and belongs to the technical field of new materials. The specific steps are as follows: firstly, preparing carbon nanosphere gels with different concentrations as a coagulation bath, putting a preparation desired polyvinylidene fluoride membrane into the carbon nanosphere coagulation bath, and preparing a CNS@PVDF membrane through a phase inversion process; secondly, synthesizing a layer of polydopamine on the surface of the CNS@PVDF membrane to obtain a dCNS@PVDF membrane, and grafting doublebonds on the surface of the membrane through a silane coupling agent to facilitate imprinting polymerization reaction; and finally, performing imprinting polymerization reaction by using ethylene glycol dimethacrylate as a cross-linking agent, acrylamide as a functional monomer and azobisisobutyronitrile as an initiator, so that a high-performance imprinted composite membrane for separating enoxacin molecules is prepared based on molecular imprinting technology. The preparation method has the advantages of simple operation, easy implementation and higher yield, and is expected to be applied to industrial production.

The invention discloses a water-soluble quaternary ammonium salinized carbon nanosphere. The water-soluble quaternary ammonium salinized carbon nanosphere is prepared via reaction between a high-molecular compound with an amino group and alkyl betaine, and comprises a carbon nanosphere mainly formed by carbon and the alkyl betaine grafted on the surface of the carbon nanosphere. The invention further discloses a preparation method of the water-soluble quaternary ammonium salinized carbon nanosphere and an application of the antibacterial aspect. Compared with the prior art, the invention completes the chemical grafting of the high-molecular compound with the amino group and the alkyl betaine and carbon nanometer granulation through a hydrothermal method by one step, and the prepared carbon nanosphere is good in water solubility, relatively low in cytotoxicity and excellent in broad-spectrum antibacterial performance.

The invention relates to the field of solid-phase microextraction and in particular discloses a solid-phase microextraction probe, and a preparation method and application of the solid-phase microextraction probe. The solid-phase microextraction probe prepared by the preparation method comprises a stainless steel fiber and a surface coating which coats one end of the stainless steel fiber. The surface coating contains carbon nanospheres; the material has the advantages of great specific surface area being 1357m<2>/g, porosity with a pore volume being 1.02cm<3>/g, high dispersion degree with PDI (Polydispersity Index) being 0.05, small grain diameter being 246nm and the like. The material is an excellent absorption material. The probe is prepared through a sol-gel method; the preparation method is simple in preparation steps and low in preparation cost; the solid-phase microextraction probe prepared by the method is controllable in thickness and not easy to damage; when the solid-phase microextraction probe is applied to analysis and detection, the solid-phase microextraction probe has the advantages of good absorption effect, strong acid-base resistance, good thermal stability, good reproducibility and the like.