Abstract:
A vertical chemical vapor deposition (CVD) reactor and a method for synthesizing metal oxide impregnated carbon nanotubes. The CVD reactor includes a preheating zone portion and a reaction zone portion, and preferably an additional cooling zone portion and a product collector. The method includes (a) subjecting a liquid reactant solution comprising an organic solvent, a metallocene, and a metal alkoxide to atomization in the presence of a gas flow comprising a carrier gas and a support gas to form an atomized mixture, and (b) heating the atomized mixture to a temperature of 200° C.−1400° C., wherein the heating forms a metal oxide and at least one carbon source compound, wherein the metallocene catalyzes the formation of carbon nanotubes from the at least one carbon source compound and the metal oxide is incorporated into or on a surface of the carbon nanotubes to form the metal oxide impregnated carbon nanotubes.
Abstract:
A method for manufacturing a carbon nanostructure according to the present invention includes a preparation step of preparing a base body, an oxidization step and a step of growing a carbon nanostructure. In the step of preparing a base body, a base body with at least a part of a contact portion or an integral portion of a catalyst member and a separation member having been oxidized is prepared. In the step of growing a carbon nanostructure, a carbon nanostructure is grown in a separation interface region between the catalyst member and the separation member. The step of growing a carbon nanostructure includes at least one of a step of locally supplying a source gas to a portion of the catalyst member facing the separation interface region where the carbon nanostructure is being grown, and a step of locally heating the separation interface region.
Abstract:
Disclosed are carbon nanotubes and a method for manufacturing the same wherein the carbon nanotubes (CNTs) which comprise a three-component carbon nanotube catalyst containing a catalytic component and an active component and have a potato or spherical shape with a particle diameter distribution (Dcnt) of 0.5 to 1.0 can be manufactured at a high yield using an impregnated supported catalyst by simultaneously removing activity and a fine powder of the impregnated supported catalyst in an attempt to solve a drawback of conventional impregnation methods for producing CNTs, namely, the difficulty in improving a yield of CNTs.
Abstract:
The present invention relates to a method of forming nanostructures or nanomaterials. The method comprises providing a thermal control barrier on a substrate and forming the nanostructures or nanomaterials. The method may, for example, be used to form carbon nanotubes by plasma enhanced chemical vapor deposition using a carbon containing gas plasma: The temperature of the substrate may be maintained at less than 350° C. while the carbon nanotubes are formed.
Abstract:
The present invention is used to produce long carbon nanotubes used, for example, in automobile and/or aircraft industry. An object of the invention is to obtain bundles of multi-walled and well oriented nanotubes of sufficient length and provide stability of continuous nanotubes producing process. The method comprises introducing a carbon-bearing component, a promoter and a precursor of a carbon nanotube growth catalyst in a carrier gas stream to form a mixture of these components; passing said mixture through the a reactor heated to an operating temperature of 1000° C. to 1200° C. and removing nanotubes formed in the reactor into a product receiver. The mixture is fed in the reactor from the bottom upwards at a linear flow velocity of 50 mm/c to 130 mm/c. When the temperature in the reactor reaches said operating temperature, the linear flow velocity of the mixture is decreased to 4-10 mm/c, and the linear flow velocity is increased to 30-130 mm/c at the outlet of the reactor. The apparatus comprises means for introducing the carbon-bearing component, the promoter and the precursor of the carbon nanotube growth catalyst in the carrier gas stream, a vertical reactor with a working chamber, means for heating the working chamber to the operating temperature, means for delivering the mixture to the working chamber of the reactor and means for removing products from the working chamber. The chamber is made of three successive sections, namely a lower inlet 16 section, a middle 17 section and an upper outlet 18 section and the diameter of the lower section 16 is ⅕ to ⅓ of the diameter of the middle section 17, while the diameter of the upper section 18 is from ¼ to ⅓ of the diameter of the middle section 17.
Abstract:
The present invention relates to a catalyst composition for the synthesis of multi-walled carbon nanotube having high apparent density in a manner of high yield. More particularly, this invention relates to a multi-component metal catalyst composition comprising i) main catalyst of Fe and Mo, ii) inactive support of Al and iii) optional co-catalyst at least one selected from Co, Ni, Ti, Mn, W, Sn or Cu. Further, the present invention affords multi-walled carbon nanotube having 5˜15 nm of fibrous diameter and 0.5˜4 μm bundle diameter.
Abstract:
The present invention relates to a continuous process for producing carbon nanotubes (herein after also referred to as “CNTS”) of single, double and/or multi-wall type, with any possible desired diameter and with high purity. The preferred embodiment provides means for continuous supply of a catalyst during the process for producing the carbon nanotubes, according to which one can achieve the advantageous continuity of the process.
Abstract:
The present invention relates to a catalyst composition for the synthesis of multi-walled carbon nanotube having high apparent density in a manner of high yield. More particularly, this invention relates to a multi-component metal catalyst composition comprising i) main catalyst of Fe and Mo, ii) inactive support of Al and iii) optional co-catalyst at least one selected from Co, Ni, Ti, Mn, W, Sn or Cu. Further, the present invention affords multi-walled carbon nanotube having 5˜15 nm of fibrous diameter and 0.5˜4 μm bundle diameter.
Abstract:
The present invention provides a method for producing a carbon nanotube having a high purity and a method for purifying an unpurified carbon nanotube or a carbon nanotube having a low purity. The method for producing a carbon nanotube comprises a step of providing a carbonaceous material containing a carbon nanotube and a step of adding an iron material and hydrogen peroxide to the carbonaceous material to thereby purity a carbon nanotube. It is preferred that an iron powder is used as the iron material. The iron powder is preferably used in a proportion of 0.5 to 20 parts by mass relative to 100 parts by mass of the whole carbonaceous material.