Provided is a method for highly efficiently producing highly pure single-walled carbon nanotubes. This method for producing carbon nanotubes by fluidized CVD includes: a step for heating a material (A) to 1200° C. or higher, in which the total mass of Al.sub.2O.sub.3 and SiO.sub.2 constitutes at least 90% of the total mass of the material (A) and the mass ratio of Al.sub.2O.sub.3/SiO.sub.2 is in the range of 1.0-2.3; and a step for bringing a gas, which is present in the environment in which the material (A) is being heated to 1200° C. or higher, into contact with a feed gas to generate carbon nanotubes.

A fabric of nanofibers that includes an adhesive is described. The nanofibers can be twisted or both twisted and coiled prior to formation into a fabric. The adhesive can be selectively applied to or infiltrated within portions of the nanofibers comprising the nanofiber fabric. The adhesive enables connection of the nanofiber fabric to an underlying substrate, even in cases in which the underlying substrate has a three-dimensional topography, while the selective location of the adhesive on the fabric limits the contact area between the adhesive and the nanofibers of the nanofiber fabric. This limited contact area can help preserve the beneficial properties of the nanofibers (e.g., thermal conductivity, electrical conductivity, infra-red (IR) radiation transparency) that otherwise might be degraded by the presence of adhesive.

The present invention relates to a carbon nanotube dispersion including carbon nanotubes, a polymer dispersant containing an amine, a phenolic compound including two or more aromatic rings, and an aqueous solvent, wherein the polymer dispersant and the phenolic compound including two or more aromatic rings are included in a weight ratio of 100:1 to 100:90, and having low viscosity and a small change of viscosity over time.

[Object] To provide a compact and reusable alkene-detection gas sensor that detects an alkene and a system using the same.

[Solving Means] An alkene-detection gas sensor that detects an alkene in a sample gas according to the present invention includes: a first reaction unit that contains a palladium catalyst and oxidizes an alkene in a sample gas to convert the alkene into an aldehyde and/or a ketone; a second reaction unit that contains hydroxylamine salts and reacts with the aldehyde and/or ketone converted in the first reaction unit to generate an acid; and a response unit that includes an electrode supporting a semiconductor material of which an electrical resistance value changes by the generated acid, in which the palladium catalyst, the hydroxylamine salts, and the semiconductor material are separated from each other.

In one aspect, provided is a method for producing a semiconducting single-walled carbon nanotube dispersion. This method allows semiconducting single-walled carbon nanotubes to be separated from a single-walled carbon nanotube mixture containing semiconducting single-walled carbon nanotubes and metallic single-walled carbon nanotubes in an aqueous medium, and yet requires only an easily available separation agent and a simple operation.

One aspect of the present disclosure relates to a method for producing a semiconducting single-walled carbon nanotube dispersion. The method includes (A) preparing a single-walled carbon nanotube dispersion to be separated that contains single-walled carbon nanotubes composed of semiconducting single-walled carbon nanotubes and metallic single-walled carbon nanotubes, an aqueous medium, and a copolymer containing a constitutional unit A derived from a monomer represented by the following formula (1) and a constitutional unit B derived from a monomer represented by the following formula (3), and (B) centrifuging the single-walled carbon nanotube dispersion to be separated and then collecting a supernatant containing the semiconducting single-walled carbon nanotubes from the centrifuged single-walled carbon nanotube dispersion.

CH.sub.2=CH−COOM  (1)

CH.sub.2=CR.sup.5−COO−(CH.sub.2CH.sub.2O).sub.q−H  (3)

In one aspect, provided is a method for producing a semiconducting single-walled carbon nanotube dispersion. This method allows semiconducting single-walled carbon nanotubes to be separated from a single-walled carbon nanotube mixture containing semiconducting single-walled carbon nanotubes and metallic single-walled carbon nanotubes in an aqueous medium, and yet requires only an easily available separation agent and a simple operation.

One aspect of the present disclosure relates to a method for producing a semiconducting single-walled carbon nanotube dispersion. The method includes (A) preparing a single-walled carbon nanotube dispersion to be separated that contains single-walled carbon nanotubes composed of semiconducting single-walled carbon nanotubes and metallic single-walled carbon nanotubes, an aqueous medium, and a nonionic polymer containing a constitutional unit A derived from a monomer represented by the following formula (1), and (B) centrifuging the single-walled carbon nanotube dispersion to be separated and then collecting a supernatant containing the semiconducting single-walled carbon nanotubes from the centrifuged single-walled carbon nanotube dispersion. A content of the constitutional unit A in all constitutional units of the polymer is 2 mol % or more. The polymer is water soluble.

CH.sub.2═CR.sup.1—COO—(EO).sub.p(PO).sub.q—R.sup.2   (1)

A nanocarbon separation method includes: a step of preparing a plurality of liquids with different specific gravities in which at least one of the plurality of liquids is a dispersion liquid in which a mixture of nanocarbons with different properties is dispersed; a step of sequentially injecting the plurality of liquids into an electrophoresis tank so that the specific gravities of the liquids decrease from a bottom to a top of the liquids in a direction of gravitational force; and a step of separating the mixture of the nanocarbons by moving a part of the mixture toward an electrode side disposed in an upper part of the electrophoresis tank and moving a remainder of the mixture toward an electrode side disposed in a lower part of the electrophoresis tank by applying a direct current voltage to the electrodes.

Provided is a fibrous carbon nanostructure that has excellent dispersibility after surface modification treatment. The fibrous carbon nanostructure has an amount of localized electrons of 1.0×10.sup.17/g or more as determined by electron spin resonance measurement at a temperature of 10 K.

An optoelectronic system can include a single walled carbon nanotube (SWNT) device. The SWNT can include a carrier-doping density with optical conditions that control trion formation that respond via optical, electrical, or magnetic stimuli. The carrier-doping density can include a hole-polaron or electron-polaron concentration.

A nanocarbon separation method includes a step of preparing a dispersion liquid having nanocarbons dispersed therein; a step of injecting a liquid including the dispersion liquid into an electrophoresis tank so that a pH of the liquid increases from a bottom to a top in a direction of gravitational force; and a step of applying a direct current to electrodes disposed in an upper part and a lower part of the electrophoresis tank.