A method of producing single-crystal spherical carbon nanoparticles

Patent metadata

Field	Value
Publication number	US-2025389048-A1
Application number	US-202218867303-A
Country	US
Kind code	A1
Filing date	Sep 30, 2022
Priority date	Sep 14, 2022
Publication date	Dec 25, 2025
Grant date	—

Abstract

The present application is related to a method of producing single-crystal spherical carbon nanoparticles that are single-crystals and spherical. The single-crystal spherical carbon nanoparticles produced by the production method of the present invention can generate fluorescence with high fluorescence quantum efficiency when excited by a light in a wide wavelength range from ultraviolet light to visible light, and have a fluorescence quantum efficiency of 10% or more compared to conventionally known carbon nanoparticles. In addition, The single-crystal spherical carbon nanoparticles produced by the production method of the present invention can be used for drug delivery, because they do not have toxicities to living organisms that compound semiconductors made of cadmium, selenium, tellurium, etc. have. Furthermore, since the single-crystal spherical carbon nanoparticles produced by the production method of the present invention are spherical, they can be densely packed as electrode materials for solar cells and secondary ion batteries, and can be used for a negative electrode for lithium batteries or an electrode material for solar cells.

First claim

1 . A method of producing single-crystal spherical carbon nanoparticles that are single-crystals and spherical, comprising a step of mixing and reacting a raw material liquid containing halogenated carbon and a reduction liquid containing an anion of a condensed aromatic compound produced from lithium, sodium or potassium and the condensed aromatic compound,
wherein the anion of the condensed aromatic compound is obtained by mixing lithium, sodium or potassium with the condensed aromatic compound at a temperature below 0° C.

2 . The method according to claim 1 , wherein an average value of a circularity calculated by the formula: 4πS/Z 2 is 0.9 or more, when using the perimeter (Z) and the area(S) of the projected image of the single-crystal spherical carbon nanoparticle observed by a transmission electron microscope.

3 . The method according to claim 1 , wherein the average particle diameter is 1 nm to 30 nm.

4 . The method according to claim 1 , wherein the raw material liquid and the reduction liquid are mixed and reacted with each other using an apparatus, and
wherein the apparatus comprises a fluid pressure imparting mechanism for imparting a predetermined pressure to fluids to be processed; at least two processing members of a first processing member and a second processing member, the second processing member being capable of approaching to and separating from the first processing member; and a rotation drive mechanism for rotating the first processing member and the second processing member relative to each other; and wherein the at least two processing members provide at least two processing surfaces of a first processing surface and a second processing surface disposed in a position facing with each other, each of the processing surfaces constitute part of a sealed flow path through which the fluid to be processed under the predetermined pressure is passed, the processing surfaces are for mixing and reacting two or more fluids to be processed, at least one of which contains a reactant, with each other, of the first and second processing members, at least the second processing member is provided with a pressure-receiving surface, and at least part of the pressure-receiving surface is comprised of the second processing surface, the pressure-receiving surface receives pressure applied to the fluids to be processed by the fluid pressure imparting mechanism and thereby generates a force to move in the direction of separating the second processing surface from the first processing surface, the fluids to be processed under the predetermined pressure are passed between the first and second processing surfaces being capable of approaching to and separating from each other, at least one of which rotates relative to the other, whereby the fluids to be processed form a thin film fluid while passing between the first and second processing surfaces, the apparatus further comprises an introduction path independent of the flow paths through which the fluids to be processed under the predetermined pressure are passed; and at least one opening leading to the introduction path and being arranged in at least either the first processing surface or the second processing surface, and at least one of the fluids to be processed is sent from the introduction path and introduced into between the first and second processing surfaces, and a reactant contained at least in any one of the aforementioned fluids to be processed is mixed with the fluids to be processed other than the fluid containing the reactant in the thin film fluid.

5 . The method according to claim 4 , wherein the opening is located downstream of a point at which the flow of the fluids to be processed that is passed between the two processing surfaces becomes a laminar flow.

6 . The method according to claim 1 , wherein the molar ratio of the lithium, sodium or potassium and the halogenated carbon is 7:1 to 4:1.

7 . The method according to claim 1 , wherein the condensed aromatic compound is at least one selected from the group consisting of biphenyl, naphthalene, 1,2-dihydronaphthalene, anthracene, phenanthrene and pyrene.

8 . The method according to claim 7 , wherein when the condensed aromatic compound is biphenyl, naphthalene or anthracene, an IR absorption spectrum of the reduction liquid shows an absorption peak in the wave number range of 1200 cm −1 to 1100 cm −1 .

9 . The method according to claim 1 , wherein the solvent contained in the reduction liquid is tetrahydrofuran and/or dimethoxyethane with residual water of 10 ppm or less.

10 . The method according to claim 1 , wherein the solvent contained in the reduction liquid is tetrahydrofuran which contains a phenolic polymerization inhibitor, and has residual water of 10 ppm or less and residual oxygen concentration of less than 0.1 ppm.

11 . The method according to claim 1 , wherein the solvent contained in the raw material liquid is tetrahydrofuran which has residual water of 10 ppm or less and a residual oxygen concentration of less than 0.1 ppm.

12 . The method according to claim 1 , wherein the halogenated carbon is carbon tetrachloride, carbon tetrabromide, or carbon tetraiodide.

13 . The method according to claim 1 , wherein the single-crystal spherical carbon nanoparticles are hexagonal and the spatial lattice is a simple lattice, a rhombohedral lattice, or a combination of a simple lattice and a rhombohedral lattice.

14 . The method according to claim 1 , wherein the single-crystal spherical carbon nanoparticles have an absorption peak in the wavenumber range of 2800 cm −1 to 2950 cm −1 in an IR absorption spectrum, and the area of the absorption peak of 1000 cm −1 to 1100 cm −1 obtained by waveform separation of the wavenumber range of 900 cm −1 to 1900 cm −1 is 15% or less of the total area of absorption peaks in the wavenumber range of 900 cm −1 to 1900 cm −1 .

15 . The method according to claim 1 , wherein in an IR absorption spectrum of the single-crystal spherical carbon nanoparticles, the area of the absorption peak of 1300 cm −1 to 1400 cm −1 obtained by waveform separation of the wavenumber range of 900 cm −1 to 1900 cm −1 is 10% or less of the total area of absorption peaks in the wavenumber range of 900 cm −1 to 1900 cm −1 .

16 . The method according to claim 1 , wherein in a Raman scattering spectrum of the single-crystal spherical carbon nanoparticles, the ratio of ID/IG is 1.0 or less, wherein IG is the intensity of the peak from 1550 cm −1 to 1650 cm −1 , and ID is the intensity of the peak from 1250 cm −1 to 1350 cm −1 .

17 . The method according to claim 1 , wherein the single-crystal spherical carbon nanoparticles have a fluorescence maximum in a wavelength range of 400 nm to 600 nm in a fluorescence spectrum.

Assignees

• M Technique Co Ltd

Inventors

• Ohkawa Hideki
• Enomura Masakazu

Classifications

• C30B7/00

  Single-crystal growth from solutions using solvents which are liquid at normal temperature, e.g. aqueous solutions (from molten solvents C30B9/00; by normal or gradient freezing C30B11/00; under a protective fluid C30B27/00) · CPC title

• C09K11/65

  containing carbon (in organic compounds C09K11/06) · CPC title

• B82Y40/00

  Manufacture or treatment of nanostructures · CPC title

• C30B29/02 Primary

  Elements · CPC title

• C01B32/15

  Nano-sized carbon materials · CPC title