The present invention provides a laminate structure in which the properties of a single-walled CNT, which are susceptible to surrounding environment, are stabilized by protecting the surface of the single-walled CNT with a proper substance, and/or another property is imparted to the single-walled CNT. The present invention provides a structure which comprises a first single-walled carbon nanotube having a length of 50 nm or longer, preferably 100 nm or longer, and a second layer laminated on the first single-walled carbon nanotube, wherein the second layer comprises at least one substance selected from the group A consisting of first boron nitride, first transition metal dichalcogenide, second carbon, first black phosphorus and first silicon.

An object is to provide an SWCNT slurry for bioimaging with reduced toxicity that causes no aggregation of semiconductor SWCNTs, no accumulation in a specific site when administered to a living organism, and no clogging in blood vessels such as those in the lungs. In order to achieve the above-described object, a semiconductor single-walled carbon nanotube (SWCNT) slurry for bioimaging according to the present invention includes: semiconductor SWCNTs having an average particle size of less than 10 nm; and a dispersant composed of an amphiphilic substance that coats the surfaces of the SWCNTs.

An object is to provide an SWCNT slurry for bioimaging with reduced toxicity that causes no aggregation of semiconductor SWCNTs, no accumulation in a specific site when administered to a living organism, and no clogging in blood vessels such as those in the lungs. In order to achieve the above-described object, a semiconductor single-walled carbon nanotube (SWCNT) slurry for bioimaging according to the present invention includes: semiconductor SWCNTs having an average particle size of less than 10 nm; and a dispersant composed of an amphiphilic substance that coats the surfaces of the SWCNTs.

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.

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.

[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.

[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 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)