Japan Science and Technology Agency

National Institute for Materials Science

Toppan Printing Co., Ltd.

Toshihiro Ando

Mika Gamo

Yafei Zhang

Kiyoharu Nakagawa

Takashi Sekiguchi

Hidenori Gamo

Tadashi Mitsui

Isao Sakaguchi

Hirokazu Oda

Yoichiro Sato

Eiji Yasu

An apparatus for synthesizing highly oriented, aligned carbon nanotubes from an alcohol includes a liquid tank for retaining an alcohol; a water cooling device for cooling the liquid tank from its outside; a condensing device for cooling and condensing vapor from the alcohol; a substrate holding device having an electrode for passing an electric current through the substrate in the alcohol; an inert gas inlet for removing air; a tank sealing device to prevent the alcohol becoming gaseous in phase; and a temperature measuring device, wherein the Si substrate with a buildup thereon of the thin film or insular particles is heated by electric current to a temperature, thereby providing a temperature gradient from the Si substrate surface toward the alcohol, wherein said thin film or insular particles is a catalyst for synthesizing carbon nanotubes, and the carbon nanotubes are synthesized.

Method of and apparatus for synthesizing highly oriented, aligned carbon nanotubes from an organic liquid

A novel carbon nanotube () is featured in that it has the highest Raman scattering intensity in the vicinity of 1580 cmin its Raman spectrum. Carbon nanotubes can be grown on and from the catalytic fine particles () which consist of ultra-fine particles of cobalt oxide catalyst onto a substrate comprising a conductive substrate () and fine particles () of catalyst formed on a surface thereof. An electron emission device () so configured as to emit electrons by applying a voltage to apical ends () of such carbon nanotubes () can be reduced in driving voltage and can achieve a current such as to emit a fluorescent material on the market for low-velocity electron beams. The electron emission device () needs no gate and can thus simplify the structure and reduce the cost of a surface light-emitting device for which the element is used. The carbon material remains unoxidized even in a low vacuum and thus allows realizing a light emitting device that can be paneled more easily, and is longer in operating life than those using a conventional electron emission device.

Carbon nanotubes, substrate and electron emission device with such carbon nanotubes and carbon nanotube synthesizing substrate as well as methods of and apparatus for making them

A nano-crystal diamond film synthesized on a substrate and containing, as a major component, nano-crystal diamond having a grain diameter from 1 nm to less than 1000 nm. This nano-crystal diamond film can be formed on a substrate by means of a plasma CVD method using a raw material gas containing a hydrocarbon and hydrogen, allowing the formation of the nano-crystal diamond film to take place outside the plasma region. This nano-crystal diamond film is applicable to the manufacture of an electrochemical device, an electrochemical electrode, a DNA chip, an organic electroluminescent device, an organic photoelectric receiving device, an organic thin film transistor, a cold electron-emission device, a fuel cell and a catalyst.

Nano-crystal diamond film, manufacturing method thereof, and device using nano-crystal diamond film

A method is disclosed whereby a functional nanomaterial such as a monolayer carbon nanotube, a monolayer boron nitride nanotube, a monolayer silicon carbide nanotube, a multilayer carbon nanotube with the number of layers controlled, a multilayer boron nitride nanotube with the number of layers controlled, a multilayer silicon carbide nanotube with the number of layers controlled, a metal containing fullerene, and a metal containing fullerene with the number of layers controlled is produced at a high yield. According to the method, when a multilayer carbon nanotube () is formed by a chemical vapor deposition or a liquid phase growth process, an endothermic reaction aid (HS) is introduced in addition to a primary reactant (CH, H) in the process to form a monolayer carbon nanotube ().

Method for preparing functional nanomaterials utilizing endothermic reaction

A method that allows producing hydrogen from methanol in a simple manner and an apparatus that is small in size and light in weight, which can produce hydrogen from methanol, are provided. The apparatus comprises a container () that retains liquid methanol () as a source material and gases () generated therein, a substrate () that is immersed in liquid methanol () in the container () loaded with a catalyst, and a power supply () for passing a direct or an alternating current through the substrate (). The substrate may be made of an oxide or oxidized material, especially oxidized diamond, and loaded with a transition metal catalyst, especially Ni catalyst. With the substrate () heated, a novel catalytic methanol decomposition reaction occurs by a combination of abrupt temperature gradient directing towards methanol from the surface of the substrate, a catalysis of the oxide or oxidized material of the substrate and a catalysis of the catalyst loaded on the substrate, and a large amount of hydrogen gas is produced.

Method of and apparatus for producing hydrogen from methanol

A fine spherical particle formed of diamond as a core and having carbon nano-materials radially grown therefrom is disclosed, which exhibits the appearance of a Marimo () particle. Fine diamond catalytic particleswhose surfaces are oxidized and treated to carry a transition metal catalyst are floated and stirred in a gas phase of hydrocarbon while being heated at a selected temperature to bring about a catalytic reaction which synthesizes carbon nano-materials and to grow them on the surface of said oxidized fine diamond particle. Nano fibers or filamentsof a nano size are grown from the fine diamond catalytic particleas a core to form-form carbon. The carbon nano-materials if the supported transition metal is Ni or Co become carbon nano-tubes and if it is Pd become coin stacked carbon nano-graphite.

Cladophora-form carbon comprising carbon nanomaterials radially grown on a spherical core, process for producing the same and production apparatus

A method capable of synthesizing carbon nanotubes at low cost and large quantities, an apparatus usable for carrying out the method, and carbon nanotubes densely aligned on and firmly bonded to a Si substrate over, and oriented perpendicular to, an entire surface thereof are provided. Highly oriented, aligned carbon nanotubes are synthesized from an organic liquid by forming a substrate with a buildup thereon of a thin film or fine insular particles composed of at least one metallic element; exposing the substrate () having the buildup to a hydrogen plasma; and heating the substrate () exposed to the hydrogen plasma in the organic liquid () to a predetermined temperature. The synthesis apparatus comprises: a liquid chamber or tank () for an organic liquid; a water cooling means () for cooling the liquid tank () from its outside; a substrate holder () for holding a substrate (), the holder having electrodes () for passing an electric current through the substrate (); a condensing means () comprising water cooling tubes () for cooling and condensing vapor made from the organic liquid by its vaporization to return it to the liquid for return into the liquid tank (); a valve () through which Ngas is introduced; and a lid () that carries the substrate holder (), the condensing means () and the valve (). The organic liquid () is thus tightly sealed in the liquid tank () by the lid (). This synthesis apparatus allows carbon nanotubes to be synthesized in large quantities, at low cost and in safety. Highly coaxially and densely oriented, aligned carbon nanotubes can be synthesized in the form of a bundle thereof, which when used in a variety of products brings about various excellent effects including extremely high usability.

Method and device for synthesizing high orientationally arranged carbon nano-tube by using organic liquid

3C-SiC nanowhisker and a method of synthesizing 3C-SiC nanowhisker wherein its diameter and length can be controlled. The method is safe and low cost, and the whisker can emit visible light of various wavelengths. 3C-SiC nanowhisker is formed by depositing thin film () made of a metal element on Si substrate (), placing this Si substrate () into a plasma CVD apparatus, and holding it for predetermined time at predetermined substrate temperature in the plasma consisting of hydrogen and hydrocarbon. Si of Si substrate () and C in plasma dissolve at supersaturation into metal liquid particles (), 3C-SiC nanowhisker () grows on the metal liquid particles (), whisker surface is terminated with H so as to maintain the diameter constant, and the metal liquid particles () at whisker root take in Si from Si substrate () and penetrate into Si substrate ().

3C-SiC nanowhisker

3C&#x2014;SiC nanowhisker and a method of synthesizing 3C&#x2014;SiC nanowhisker wherein its diameter and length can be controlled. The method is safe and low cost, and the whisker can emit visible light of various wavelengths. 3C&#x2014;SiC nanowhisker is formed by depositing thin film () made of a metal element on Si substrate (), placing this Si substrate () into a plasma CVD apparatus, and holding it for predetermined time at predetermined substrate temperature in the plasma consisting of hydrogen and hydrocarbon. Si of Si substrate () and C in plasma dissolve at supersaturation into metal liquid particle (), 3C&#x2014;SiC nanowhisker () grows on the metal liquid particles (), whisker surface is terminated with H so as to maintain the diameter constant, and the metal liquid particles () at whisker root take in Si from Si substrate () and penetrate into Si substrate ().

3C-SIC nanowhisker and synthesizing method and 3C-SIC nanowhisker

A substrate is polished and made an inclined substrate, which is exposed to a hydrogen plasma and is thereby smoothened. The substrate is then heated controlledly until it surface temperature reaches 830&#xb0; C. Meanwhile, a gas mixture of 1% methane, 50 ppm hydrogen sulfide and hydrogen is introduced in a tubular reaction vessel to flow therethrough at 200 ml/min, where microwave plasma is excited to cause n-type semiconductor diamond to epitaxially grow on the substrate. An ion doped n-type semiconductor is thus formed that has a single donor level of an activation energy at 0.38 eV and is high in mobility and of high quality.

Growing community of inventors

Ibaraki, Japan

Toshihiro Ando