Heteratomic-doped nanodiamond particles and method for producing heteroatomic-doped nanodiamond particles

Abstract

The present invention provides heteroatom-doped nanodiamond particles having a fluorescence emission peak derived from the Si-Vacancy (Si-V) center and satisfying the following conditions: (i) when 1 μL of an aqueous suspension of 1 mass% of said particles is added dropwise onto a glass substrate, and fluorescence spectra at 101×101 points with a spatial resolution of 1 μm and in a sample range of 100 μm×100 μm are acquired using a microscopic Raman device, the proportion of the number of bright spots that emit fluorescence having a ZPL peak at ZPL±X nm (0≤X≤5) of the heteroatom-V center is at least 50%; and (ii) the average size of primary particles is 2-70 nm.

Description

Technical Field

[0001] The present invention relates to heteroatom-doped nanodiamond particles and a method for producing heteroatom-doped nanodiamonds.

Background Art

[0002] The luminescence center of diamond is a nanosized and chemically stable fluorescent chromophore, and since it does not exhibit in vivo degradation, fading, or blinking, which are often seen in organic phosphors, it is expected to be a probe for fluorescence imaging. Also, since it may be possible to measure the spin information of electrons excited within the luminescence center from the outside, its use in ODMR (Optically Detected Magnetic Resonance) and as a quantum bit is also expected.

[0003] Patent Document 1 discloses nanodiamonds doped with heteroatoms such as Si.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] One object of the present invention is to provide a method for producing heteroatom-doped nanodiamond particles and heteroatom-doped nanodiamond particles having higher fluorescence intensity and concentration of the fluorescent substance and better quality.

Means for Solving the Problems

[0006] The present invention provides the following heteroatom-doped nanodiamond particles and a method for producing heteroatom-doped nanodiamond particles. 〔1〕 Heteroatom-doped nanodiamond particles having a fluorescence emission peak derived from a heteroatom-Vacancy (heteroatom-V) center, satisfying the following conditions (i) to (ii): (i) When 1 μL of a 1% by mass aqueous suspension of the particles is dropped onto a glass substrate and a fluorescence spectrum is obtained using a microscopic Raman apparatus for 101 × 101 points in a sample range of 100 μm × 100 μm with a spatial resolution of 1 μm, the ratio of the number of bright spots emitting fluorescence at the ZPL peak at ZPL ± X nm (0 ≦ X ≦ 5) of the heteroatom-V center is 50% or more. (ii) The average size of the primary particles is 2 to 70 nm. 〔2〕 The heteroatom-doped nanodiamond particles according to 〔1〕, wherein the heteroatom is a Group 14 element selected from the group consisting of Si, Ge, Sn, and Pb. 〔3〕 The heteroatom-doped nanodiamond particles according to 〔1〕 or 〔2〕, wherein the heteroatom is Si, and when​​​​​​​​​​​​​[6] Heteratomic doped nanodiamond particles described in any one of items [1] to [5] that satisfy the following conditions (a) and / or (b): (a) The zeta potential of the particle is -70mV to 70mV, (b) The pH of the particles when dispersed in water at a concentration of 3 wt% is 1 to 12. [7] Heteratomic doped nanodiamond particles according to any one of [1] to [6], wherein the shape of the particles is spherical, ellipsoidal, or polyhedral. [8] The BET specific surface area of ​​the particles is 20 to 900 m 2 Heteratomic doped nanodiamond particles as described in any of [1] to [7], wherein the particle size is / g. [9] Heteratomic doped nanodiamond particles according to any one of [1] to [8], wherein the proportion of the number of bright spots is 90% or more.

[10] A method for producing heteroatom-doped nanodiamond particles, comprising treating a heteroatom-doped nanodiamond raw material produced by detonation with the following (I) and / or (II): (I) Oxidation treatment at 500-650°C, (II) Hydrogenation treatment at 300-1200°C.

[11] The manufacturing method according to

[10] , wherein the oxidation treatment is carried out in an atmosphere with an oxygen concentration of 1 to 100%.

[12] The manufacturing method according to

[10] , wherein the hydrogenation treatment is carried out in an atmosphere with a hydrogen concentration of 1 to 100%. [Effects of the Invention]

[0007] The method of the present invention significantly increases the fluorescence concentration of heteroatom-doped nanodiamond particles such as Si, or of the bulk or aggregate of such particles, thereby further improving their usefulness as fluorescence imaging probes, ODMR (Optically Detected Magnetic Resonance), and qubits. [Brief explanation of the drawing]

[0008] [Figure 1](a) Fluorescence microscope image of Si-doped nanodiamond particles oxidized at 570°C, (b) Fluorescence microscope image of Si-doped nanodiamond particles oxidized at 570°C and then hydrogenated at 550°C. [Figure 2] The relationship between the peak area ratio (sp2 carbon / sp3 carbon) and the number of bright spots of the Si-doped nanodiamond particles obtained in Comparative Examples 1-4 and Examples 1 and 2 is shown. [Figure 3] Fluorescence image of GeV fluorescent ND treated with gas-phase oxidation at 470°C for 2 hours in Comparative Example 5. [Figure 4] Fluorescence image of GeV fluorescent ND treated with gas-phase oxidation at 520°C for 2 hours in Example 3. [Modes for carrying out the invention]

[0009] The heteroatom-doped nanodiamond particles of the present invention satisfy the following conditions (i) to (ii): (i) When 1 μL of a 1 mass% aqueous suspension of the particles is dropped onto a glass substrate and a fluorescence spectrum is acquired using a micro-Raman spectrometer for 10¹ × 10¹ points in a sample area of ​​100 μm × 100 μm with a spatial resolution of 1 μm, the proportion of bright spots that emit fluorescence at the ZPL peak in ZPL ± X nm (0 ≤ X ≤ 5) of heteroatom-V centers is 50% or more. (ii) The average size of the primary particles is preferably 2 to 70 nm, more preferably 2.5 to 60 nm, even more preferably 3 to 55 nm, and particularly preferably 3.5 to 50 nm. An example of a micro-Raman spectrophotometer for measuring the number of bright spots is the LabRAM HR Evolution micro-laser Raman spectrophotometer manufactured by Horiba, Ltd. When high-speed mapping is performed on 10¹ × 10¹ points in a sample area of ​​100 μm × 100 μm with excitation light of 488 nm, 532 nm, or 633 nm and a spatial resolution of 1 μm using a micro-Raman spectrophotometer, and bright spot imaging of ZPL±X nm (0 ≤ X ≤ 5) is performed to obtain a fluorescence spectrum, the percentage of bright spots that emit fluorescence in ZPL±X nm (0 ≤ X ≤ 5) from heteroatom-V centers is preferably 50% or more, more preferably 80% or more, even more preferably 90% or more, and most preferably 100%. In ZPL±X nm (0 ≤ X ≤ 5), X is any number between 0 nm and 5 nm. Bright spot imaging may be performed at ZPL (±0nm), or in ranges such as ZPL±0.5nm, ZPL±1nm, ZPL±2nm, ZPL±3nm, ZPL±4nm, and ZPL±5nm, with the maximum wavelength range being ZPL±5nm. Since the wavelength of ZPL (peak top wavelength) can vary depending on the structure of the fluorescence center, the number of fluorescent spots emitting light from the ZPL peak within the range of "ZPL±Xnm (0≦X≦5)" was measured and its ratio was calculated. For example, in the case of SiV, both cases are possible: the ZPL is 738nm (±0nm) and the ZPL is slightly shifted from 738nm. However, even if the ZPL is slightly shifted, it is unlikely to deviate by more than 5nm from the known ZPL (738nm), so it will fall within the range of ZPL±Xnm (0≦X≦5). Since the ZPL peak waveform is stored in the micro-Raman spectrometer, the presence or absence of a ZPL peak is determined within the range of ZPL±Xnm (0≦X≦5) at each 101×10¹ point, and if a ZPL peak is found, it is counted as a bright spot. For example, if the ZPL shift is 0 nm, the number of bright spots emitting fluorescence from the ZPL peak will not change regardless of whether the measurement is performed at ZPL, ZPL±0.5 nm, ZPL±1 nm, ZPL±2 nm, ZPL±3 nm, ZPL±4 nm, or ZPL±5 nm. ZPL±Xnm (0≦X≦5) is a wavelength range set to reliably capture bright spots emitting fluorescence from the ZPL peak. The maximum number of bright spots is 101×10¹=10201, and when there are 10201 bright spots, the proportion of bright spots emitting fluorescence at ZPL±Xnm (0≦X≦5) for heteroatom-V centers is 100%. When the percentage of bright spots is 50% or more, the number of bright spots will be 5101 or more. The measurement of the number of bright spots may be performed in the center, intermediate layer, or outer periphery of the glass substrate, but preferably at least inside the sample coating area. The percentage of bright spots should preferably be 50% or more, more preferably 80% or more, even more preferably 90% or more, and most preferably 100% in at least one of the center, intermediate layer, or outer periphery; more preferably 50% or more, more preferably 80% or more, even more preferably 90% or more, and most preferably 100% in at least two of the center, intermediate layer, or outer periphery; and most preferably 50% or more, more preferably 80% or more, even more preferably 90% or more, and most preferably 100% in all of the center, intermediate layer, and outer periphery. The center refers to the area where the drop-coated suspension dries last, and the outer periphery refers to the thick coating area that forms a coffee ring shape on the outer periphery of the coating area. The intermediate layer refers to the area between the outer periphery and the center. The average size of primary particles can be determined from the results of powder X-ray diffraction (XRD) analysis using Scherrer's formula. An example of an XRD measuring device is a fully automated multi-purpose X-ray diffractometer (manufactured by Rigaku Corporation).

[0010] sp obtained from heteroatom-doped nanodiamond particles of the present invention by Raman spectroscopy 2 Carbon and sp 3 Carbon peak area ratio (sp2 Carbon / sp 3 The ratio of carbon) is preferably 0.01 to 7, 0.05 to 3, preferably 0.1 to 1.2, more preferably 0.1 to 1, still more preferably 0.1 to 0.5, and even more preferably 0.1 to 0.3. By the oxidation treatment of the present invention, the ratio of sp2 carbon can be reduced and the fluorescence intensity can be increased. sp 2 Carbon and sp 3 The peak area ratio of carbon (sp 2 Carbon / sp 3 The ratio of carbon) can be measured by microscopic Raman spectroscopy using, for example, a 325 nm laser and a microscopic Raman spectrometer. Sp 2 The peak area of carbon is 1250 cm -1 And the total area of two peaks appearing around 1328 cm -1 refers to the sum of the areas of two peaks that appear near 1328 cm, and sp 3 The peak area of carbon is 1500 cm -1 And the total area of two peaks that appear near 1590 cm -1 refers to the sum of the areas of two peaks that appear near 1590 cm. As the microscopic Raman spectrometer, for example, a microscopic laser Raman spectrophotometer LabRAM HR Evolution (manufactured by Horiba, Ltd.) can be used. In one embodiment, the heteroatom-doped nanodiamond particles of the present invention have a plus or minus zeta potential. The preferred zeta potential of the heteroatom-doped nanodiamond particles is preferably -70 mV or more or 70 mV or less, more preferably -60 mV or more or 30 mV or less. In one preferred embodiment of the present invention, the zeta potential of the heteroatom-doped nanodiamond is preferably -70 to 70 mV, more preferably -60 to 30 mV.

[0011] When the heteroatom-doped nanodiamond particles of the present invention are dispersed in water at a concentration of 3 wt%, the pH is preferably 1 to 12. The shape of the heteroatom-doped nanodiamond particles of the present invention is not particularly limited, but preferably includes spherical, ellipsoidal or polyhedral shapes.

[0012] The BET specific surface area of ​​the heteroatom-doped nanodiamond particles of the present invention is preferably 20 to 900 m². 2 / g, 25-800 m 2 / g, 30-700 m 2 / g, 35-600 m 2 / g, 50-500 m 2 / g, 100-400 m 2 / glute 200~300 m 2 The value is / g. The BET specific surface area can be measured by nitrogen adsorption. An example of a BET specific surface area measuring device is the BELSORP-miniII (manufactured by Microtrac-Bell Co., Ltd.). The BET specific surface area can be measured under the following conditions, for example. ·Measurement amount of powder: 40mg • Pre-drying: Process at 120°C under vacuum for 3 hours. • Measurement temperature: -196°C (liquid nitrogen temperature)

[0013] The heteroatom content of the heteroatom-doped nanodiamonds of the present invention is preferably 0.0001 to 10.0 mass%, more preferably 0.0001 to 5.0 mass%, and even more preferably 0.0001 to 1.0 mass%. The heteroatom content can be measured, for example, by inductively coupled plasma atomic emission spectrometry (ICP-AES), XRF, or SIMS (secondary ion mass spectrometry). When the heteroatom content of the heteroatom-doped nanodiamonds is a Group 14 element such as Si, Ge, Sn, or Pb, it can be quantified as an acidic solution after alkali fusion. The concentration of heteroatom-V centers in the heteroatom-doped nanodiamond particles of the present invention is preferably 1 × 10⁻¹⁶ 10 / cm 3 That is all, more 2 × 10 10 ~1 × 10 19 / cm 3 The concentration of heteroatom-V centers is estimated to be identifiable, for example, by using a confocal laser microscope or a fluorescence absorption spectrometer. For information on determining the concentration of heteroatom-V centers by fluorescence absorption analysis, please refer to the reference (DOI 10.1002 / pssa.201532174).

[0014] In this specification, heteroatoms are selected from the group consisting of B, P, Si, S, Cr, Sn, Al, Ge, Li, Na, K, Cs, Mg, Ca, Sr, Ba, Ti, Zr, V, Nb, Ta, Mo, W, Mn, Fe, Ni, Cu, Ag, Zn, Cd, Hg, Ga, In, Tl, Pb, As, Sb, Bi, Se, Te, Co, Xe, F, Y, and lanthanides, preferably selected from the group consisting of Si, Ge, Sn, B, P, Ni, Ti, Co, Xe, Cr, W, Ta, Zr, Zn, Ag, Pb, and lanthanides, and more preferably selected from the group consisting of Si, Ge, Sn, B, P, Ni, Ti, Co, Xe, Cr, W, Ta, Zr, Zn, Ag, and Pb. Preferred heteroatoms for doping nanodiamonds are Group 14 elements selected from the group consisting of Si, Ge, Sn, and Pb, B (boron), P (phosphorus), and Ni, while more preferred heteroatoms are Si, B, and P.

[0015] In one preferred embodiment, the nanodiamond particles obtained by the manufacturing method of the present invention include a Group 14 element selected from the group consisting of Si, Ge, Sn, and Pb, at least one element selected from the group consisting of B, P, and Ni, and at least one other heteroatom. In another preferred embodiment, the nanodiamond particles obtained by the manufacturing method of the present invention contain at least one selected from the group consisting of Si, B, P, and Ni, and at least one other heteroatom. The number of heteroatoms doped into the nanodiamond particles obtained by the manufacturing method of the present invention is preferably 1 to 5, more preferably 1 to 4, and even more preferably 1, 2, or 3.

[0016] The heteroatom-doped nanodiamond raw material used in the manufacturing method of the present invention can be produced, for example, by a detonation method which includes the steps of mixing an explosive composition containing at least one explosive and at least one heteroatom compound, and detonating the resulting mixture in a sealed container. Examples of containers include metal containers and synthetic resin containers. The explosive and heteroatom compound are preferably formed by pressing or casting. Examples of methods for producing particles (dry powders) of the explosive and heteroatom compound include crystallization, crushing, and spray flash evaporation. The fluorescence intensity of heteroatom-doped nanodiamond raw materials can be increased by oxidation and / or hydrogenation treatment. Preferably, oxidation and hydrogenation treatments are performed, more preferably oxidation treatment is performed first, followed by hydrogenation treatment.

[0017] Temperature is crucial for oxidation treatment; below 470°C, it is not possible to reduce the proportion of sp2 carbons and increase fluorescence intensity. The lower limit of the oxidation treatment temperature is preferably 500°C, 510°C, 520°C, 530°C, 540°C, and 550°C, and the upper limit is 650°C, 640°C, 630°C, 620°C, 610°C, 600°C, and 590°C. The most preferred oxidation treatment temperature is 550-590°C. The oxygen concentration in the atmosphere during oxidation treatment is preferably 1-100 v / v%, 1-50 v / v%, 1-25 v / v%, and more preferably 1-10 v / v%. The oxidation treatment time is preferably 0.5-20 hours, 0.5-10 hours, 1-5 hours, and more preferably 1-3 hours. The hydrogenation temperature is also important. The lower limit of the hydrogenation temperature is preferably 300°C, 350°C, 400°C, 410°C, 420°C, or 430°C, and the upper limit of the hydrogenation temperature is preferably 1200°C, 1210°C, 1220°C, or 1230°C. The hydrogen concentration in the atmosphere during the hydrogenation treatment is preferably 1 to 100 v / v%, 1 to 50 v / v%, 1 to 25 v / v%, more preferably 1 to 10 v / v%. The hydrogenation treatment time is preferably 1 to 10 hours, 2 to 9 hours, 3 to 8 hours, more preferably 4 to 7 hours.

[0018] The preferred heteroatom-doped nanodiamond particles obtained by the manufacturing method of the present invention have a fluorescence emission peak due to the heteroatom-V center. The wavelength of the fluorescence emission peak is preferably 720-770 nm, more preferably 730-760 nm, when the heteroatom contains silicon; preferably 580-630 nm, more preferably 590-620 nm, when the heteroatom contains germanium; preferably 590-650 nm, more preferably 600-640 nm, when the heteroatom contains tin; and preferably 540-600 nm, more preferably 550-590 nm, when the heteroatom contains lead.

[0019] In one preferred embodiment of the present invention, heteroatom-doped nanodiamond particles obtained by the manufacturing method of the present invention, which emit fluorescence from heteroatom-vacancy centers where the heteroatom is other than phosphorus or boron, may be further doped with phosphorus and / or boron. It is believed that the introduction of these atoms (B and / or P) has the effect of adjusting the charge of heteroatom-V centers other than B and / or P and defects (luminescence centers) originating from other doped heteroatoms, thereby stabilizing the fluorescence. Furthermore, heteroatom-doped nanodiamonds obtained by the manufacturing method of the present invention and heteroatom-doped nanodiamond particles of the present invention may also contain fluorescence emission from NV centers. NV centers are luminescence centers consisting of nitrogen and vacancies, and have a broad fluorescence spectrum with ZPL (zero phonon line) peaks around 575 nm and / or 637 nm, for example, a broad fluorescence spectrum of about 550 to 800 nm when excited at 532 nm. For example, doping with heteroatoms that are not directly related to fluorescence, such as phosphorus and boron, may increase the intensity of NV centers, which is preferable. In one more preferred embodiment of the present invention, the fluorescence emission peak of Si-doped nanodiamond particles includes a sharp peak of approximately 738 nm, known as the ZPL (Zero Phonon Line). Note that the ZPL of Ge-V is approximately 602 nm, the ZPL of Sn-V is approximately 620 nm, and the ZPL of Pb-V is approximately 552 nm.

[0020] The concentration of at least one heteroatom V-center in the heteroatom-doped nanodiamond particles obtained by the manufacturing method of the present invention is preferably 1 × 10⁻¹⁶ 10 / cm 3 That is all, more 2 × 10 10 ~1 × 10 19 / cm 3 This is the concentration of heteroatomic V-centers. If a nanodiamond contains two or more heteroatomic V-centers, this concentration is the sum of those centers. It is estimated that the concentration of heteroatomic V-centers can be determined, for example, using a confocal laser microscope or a fluorescence absorption spectrometer. For information on determining the concentration of heteroatomic V-centers by fluorescence absorption analysis, please refer to the reference (DOI 10.1002 / pssa.201532174). A heteroatomic compound is a compound containing at least one heteroatom (an atom other than carbon), and may be either an organic compound or an inorganic compound.

[0021] The average size of the primary particles of heteroatom-doped nanodiamonds obtained by the manufacturing method of the present invention is preferably 2 to 70 nm, more preferably 2.5 to 60 nm, even more preferably 3 to 55 nm, and particularly preferably 3.5 to 50 nm. The average size of the primary particles can be determined from the results of powder X-ray diffraction (XRD) analysis using Scherrer's formula. An example of an XRD measuring device is a fully automated multi-purpose X-ray diffractometer (manufactured by Rigaku Corporation).

[0022] The carbon content of the heteroatom-doped nanodiamond particles obtained by the manufacturing method of the present invention is preferably 70 to 99% by mass, more preferably 75 to 98% by mass, and even more preferably 80 to 97% by mass. The hydrogen content of the heteroatom-doped nanodiamond particles obtained by the manufacturing method of the present invention is preferably 0.1 to 5% by mass, more preferably 0.2 to 4.5% by mass, and even more preferably 0.3 to 4.0% by mass. The nitrogen content of the heteroatom-doped nanodiamond particles obtained by the manufacturing method of the present invention is preferably 0.1 to 5% by mass, more preferably 0.2 to 4.5% by mass, and even more preferably 0.3 to 4.0% by mass. The carbon, hydrogen, and nitrogen content of heteroatom-doped nanodiamonds obtained by the manufacturing method of the present invention can be measured by elemental analysis.

[0023] The heteroatom content of heteroatom-doped nanodiamonds obtained by the manufacturing method of the present invention is preferably 0.0001 to 10.0 mass%, more preferably 0.0001 to 5.0 mass%, and even more preferably 0.0001 to 1.0 mass%. The heteroatom content can be measured, for example, by inductively coupled plasma atomic emission spectrometry (ICP-AES), XRF, or SIMS (secondary ion mass spectrometry), and the heteroatom-doped nanodiamonds can be quantified as an acidic solution after alkali fusion. Furthermore, if the nanodiamonds contain two or more heteroatoms, the heteroatom content is the total content of those atoms.

[0024] Heteratomic doped nanodiamond particles of one preferred embodiment obtained by the manufacturing method of the present invention can be identified by Raman spectroscopy as having characteristic peaks for diamond, graphite, surface hydroxyl groups (OH), and surface carbonyl groups (CO) in the Raman shift chart. The peak characteristic of diamond in the Raman shift chart is at 1100-1400 cm⁻¹. -1 The characteristic peak of graphite is 1450-1700cm. -1 The peak characteristic of surface hydroxyl groups (OH) is at 1500-1750 cm⁻¹. -1 The peak characteristic of surface carbonyl groups (CO) is at 1650-1800 cm⁻¹. -1 The characteristic peak areas for diamond, graphite, surface hydroxyl groups (OH), and surface carbonyl groups (CO) are shown by a Raman spectrometer. The laser wavelength of the Raman light source is, for example, 325 nm or 488 nm. A confocal micro-Raman spectrometer (for example, product name: Micro-Laser Raman Spectrophotometer LabRAM HR Evolution, manufactured by Horiba, Ltd.) can be used as the Raman spectrometer. In heteroatom-doped nanodiamond particles of one preferred embodiment obtained by the manufacturing method of the present invention, the ratio of the peak area of ​​diamond (D) to the peak area of ​​graphite (G) (D / G) is preferably 0.2 to 9, more preferably 0.3 to 8, and even more preferably 0.5 to 7.

[0025] In heteroatom-doped nanodiamond particles of one preferred embodiment obtained by the manufacturing method of the present invention, the ratio (H / D) of the peak area of ​​surface hydroxyl groups (OH) to the peak area of ​​diamond (D) is preferably 0.1 to 5, more preferably 0.1 to 4.0, and even more preferably 0.1 to 3.0. In heteroatom-doped nanodiamond particles of one preferred embodiment obtained by the manufacturing method of the present invention, the ratio (C / D) of the peak area of ​​the surface carbonyl group (CO) (C) to the peak area of ​​the diamond (D) is preferably 0.01 to 1.5, more preferably 0.03 to 1.2, and even more preferably 0.05 to 1.0. For Raman analysis techniques of nanodiamond particles, refer to the literature (e.g., Vadym N. Mochalin et al., NATURE NANOTECHNOLOGY, 7(2012)11-23, especially Figure 3).

[0026] In another preferred embodiment of the present invention, heteroatom-doped nanodiamond particles obtained by the production method of the present invention may have at least one oxygen functional group terminator and / or at least one hydrogen terminator on their surface. Examples of oxygen functional group terminators include OH, COOH, CONH2, C=O, and CHO, with OH, C=O, and COOH being preferred. Examples of hydrogen terminators include alkyl groups having 1 to 20 carbon atoms. The presence of at least one oxygen functional group terminator on the surface of the heteroatom-doped nanodiamond particles obtained by the manufacturing method of the present invention is preferable because it suppresses aggregation of the nanodiamond particles. The presence of at least one hydrogen terminator on the surface of the heteroatom-doped nanodiamond particles obtained by the manufacturing method of the present invention is preferable because it results in a positive zeta potential, leading to stability and high dispersion in acidic aqueous solutions.

[0027] In another preferred embodiment of the present invention, heteroatom-doped nanodiamond particles obtained by the manufacturing method of the present invention may have a core-shell structure. The core of the heteroatom-doped nanodiamond particles with a core-shell structure obtained by the manufacturing method of the present invention is a nanodiamond particle doped with at least one heteroatom. Preferably, this core has heteroatom V centers and emits fluorescence. The shell is a non-diamond coating layer, which may contain sp2 carbon and preferably oxygen atoms. The shell may also be a graphite layer. The thickness of the shell is preferably 5 nm or less, more preferably 3 nm or less, and even more preferably 1 nm or less. The shell may have hydrophilic functional groups on its surface.

[0028] The shape of the heteroatom-doped nanodiamond particles obtained by the manufacturing method of the present invention is preferably spherical, ellipsoidal, or a polyhedron close to these shapes. In the manufacturing method of the present invention, the mixing of the explosive and the heteroatomic compound in the detonation method may be performed in the presence or absence of a solvent, and the mixture can be molded by a pressing method or a pouring method. The average particle size of the explosives and heteroatomic compounds is preferably 10 mm or less, more preferably 5 mm or less, and even more preferably 1 mm or less. These average particle sizes can be measured by laser diffraction / scattering, optical microscopy, or Raman spectroscopy. The product obtained by the explosion can be subjected to further purification and post-treatment steps of the present invention. The purification step may include either or both of mixed acid treatment and alkali treatment. The preferred purification step is mixed acid treatment.

[0029] When an explosive composition containing explosives and heteroatomic compounds is detonated in a container, in addition to heteroatomic-doped nanodiamonds, graphite, metal impurities, individual heteroatoms, and heteroatomic oxides are produced. Graphite and metal impurities can be removed by mixed acid treatment, and if the heteroatoms are Group 14 elements such as Si, Ge, Sn, and Pb, the individual Group 14 elements (Si, Ge, Sn, Pb) and Group 14 element oxides (SiO2, GeO2, SnO, SnO2, PbO, PbO2, etc.) can be removed by alkali treatment. The mixed acid can be a mixture of concentrated sulfuric acid and concentrated nitric acid, preferably a mixture of concentrated sulfuric acid and concentrated nitric acid in a volume ratio of 1:1. The temperature for the mixed acid treatment is 50 to 200°C, and the treatment time is 0.5 to 24 hours.

[0030] Examples of alkalis include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide. The alkali treatment temperature is 30 to 150°C, and the treatment time is 0.5 to 24 hours. The post-processing step may include annealing. Annealing allows doped heteroatoms in heteroatom-doped nanodiamonds to meet vacancies, forming heteroatom V-centers. Although optional, a vacancy formation step may be performed before annealing. The vacancy formation step is performed by irradiation with an ion beam or electron beam. Heteroatom V-centers can be formed by annealing even without the vacancy formation step, but performing annealing after the vacancy formation step can form more heteroatom V-centers. The vacancy density introduced by ion beam irradiation or electron beam irradiation should be limited to a concentration where the diamond is destroyed (>1 × 10⁻¹⁶). 21 / cm 3 It is limited by the vacancy concentration, but the lower limit is, for example, 1 × 10⁻⁶ 16 / cm 3 In addition to the above, 1 x 10 18 / cm 3That concludes the explanation. The ion beam is preferably a hydrogen (H) or helium (He) ion beam. For example, the energy of the hydrogen ion beam is preferably 10 to 1500 keV, and the energy of the helium ion beam is preferably 20 to 2000 keV. The energy of the electron beam is preferably 500 to 5000 keV. The annealing temperature is preferably 800°C or higher, and the annealing time is 30 minutes or longer.

[0031] The explosives used are not particularly limited, and a wide range of known explosives can be used. Specific examples include trinitrotoluene (TNT), cyclotrimethylenetrinitramine (Hexogen, RDX), cyclotetramethylenetetranitramine (Octogen), trinitrophenylmethylnitramine (Tetrill), pentaerythritol tetranitrate (PETN), tetranitromethane (TNM), triaminotrinitrobenzene, hexanitrostilbene, and diaminodinitrobenzofloxane, which can be used individually or in combination of two or more.

[0032] The heteroatomic compounds listed below are merely illustrative examples, and a wide range of known heteroatomic compounds can be used. When the heteroatom is silicon, the organic silicon compounds are: Silanes having lower alkyl groups such as acetoxytrimethylsilane, diacetoxydimethylsilane, triacetoxymethylsilane, acetoxytriethylsilane, diacetoxydiethylsilane, triacetoxyethylsilane, acetoxytripropylsilane, methoxytrimethylsilane, dimethoxydimethylsilane, trimethoxymethylsilane, ethoxytrimethylsilane, diethoxydimethylsilane, triethoxymethylsilane, ethoxytriethylsilane, diethoxydiethylsilane, triethoxyethylsilane, and trimethylphenoxysilane.

[0033] Trichloromethylsilane, dichlorodimethylsilane, chlorotrimethylsilane, trichloroethylsilane, dichlorodiethylsilane, chlorotriethylsilane, trichlorophenylsilane, dichlorodiphenylsilane, chlorotriphenylsilane, dichlorodiphenylsilane, dichloromethylphenylsilane, dichloroethylphenylsilane, chlorodifluoromethylsilane, dichlorofluoromethylsilane, chlorofluorodimethylsilane, chloroethyldifluorosilane, dichloroethylfluorosilane, chlorodifluoropropylsilane, dichlorofluoropropyl Silanes containing halogen atoms, such as pyrusilane, trifluoromethylsilane, difluorodimethylsilane, fluorotrimethylsilane, ethyltrifluorosilane, diethyldifluorosilane, triethylfluorosilane, trifluoropropylsilane, fluorotripropylsilane, trifluorophenylsilane, difluorodiphenylsilane, fluorotriphenylsilane, tribrommethylsilane, dibromdimethylsilane, bromtrimethylsilane, bromtriethylsilane, bromtripropylsilane, dibromdiphenylsilane, and bromtriphenylsilane.

[0034] Polysilanes such as hexamethyldisilane, hexaethyldisilane, hexapropyldisilane, hexaphenyldisilane, and octaphenylcyclotetrasilane. Silazanes such as triethylsilazane, tripropylsilazane, triphenylsilazane, hexamethyldisilazane, hexaethyldisilazane, hexaphenyldisilazane, hexamethylcyclotrisilazane, octamethylcyclotetrasilazane, hexaethylcyclotrisilazane, octaethylcyclotetrasilazane, and hexaphenylcyclotrisilazane. Aromatic silanes, such as silabenzene and disilabenzene, have silicon atoms incorporated into their aromatic rings. Hydroxyl group-containing silanes such as trimethylsilanol, dimethylphenylsilanol, triethylsilanol, diethylsilanediol, tripropylsilanol, dipropylsilanediol, triphenylsilanol, and diphenylsilanediol.

[0035] Alkyl or aryl-substituted silanes such as tetramethylsilane, ethyltrimethylsilane, trimethylpropylsilane, trimethylphenylsilane, diethyldimethylsilane, triethylmethylsilane, methyltriphenylsilane, tetraethylsilane, triethylphenylsilane, diethyldiphenylsilane, ethyltriphenylsilane, and tetraphenylsilane. • Carboxyl group-containing silanes such as triphenylsilylcarboxylic acid, trimethylsilylacetic acid, trimethylsilylpropionic acid, and trimethylsilylbutyric acid.

[0036] Siloxanes such as hexamethyldisiloxane, hexaethyldisiloxane, hexapropyldisiloxane, and hexaphenyldisiloxane. Silanes having an alkyl or aryl group and a hydrogen atom, such as methylsilane, dimethylsilane, trimethylsilane, diethylsilane, triethylsilane, tripropylsilane, diphenylsilane, and triphenylsilane. Tetrakis(chloromethyl)silane, tetrakis(hydroxymethyl)silane, tetrakis(trimethylsilyl)silane, tetrakis(trimethylsilyl)methane, tetrakis(dimethylsilanolyl)silane, tetrakis(tri(hydroxymethyl)silyl)silane, tetrakis(nitratemethyl)silane, These are some examples.

[0037] Inorganic silicon compounds include silicon oxide, silicon oxynitride, silicon nitride, silicon carbide oxide, silicon carbide nitride, silane, or silicon-doped carbon materials. Examples of silicon-doped carbon materials include graphite, activated carbon, carbon black, Ketjenblack, coke, soft carbon, hard carbon, acetylene black, carbon fiber, and mesoporous carbon. Examples of boron compounds include inorganic boron compounds and organoboron compounds. Examples of inorganic boron compounds include orthoboric acid, diboron dioxide, diboron trioxide, tetraboron trioxide, tetraboron pentoxide, boron tribromide, tetrafluoroboric acid, ammonium borate, and magnesium borate.

[0038] Examples of organoboron compounds include triethylborane, (R)-5,5-diphenyl-2-methyl-3,4-propano-1,3,2-oxazaborolidine, triisopropyl borate, 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane, bis(hexyleneglycolato)diborone, 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolane-2-yl)-1H-pyrazole, tert-butyl-N-[4-(4,4,5,5-tetramethyl-1,2,3-dioxaborolane-2-yl)phenyl]carbamate, phenylboronic acid, 3-acetylphenylboronic acid, borotetraacetic acid trifluoride complex, boron trifluoride sulfolane complex, 2-thiopheneboronic acid, and tris(trimethylsilyl)borate. Examples of phosphorus compounds include inorganic phosphorus compounds and organic phosphorus compounds. Examples of inorganic phosphorus compounds include ammonium polyphosphate.

[0039] Examples of organophosphorus compounds include trimethyl phosphate, triethyl phosphate, tripropyl phosphate, tributyl phosphate, tripentyl phosphate, trihexyl phosphate, dimethylethyl phosphate, methyl dibutyl phosphate, ethyl dipropyl phosphate, 2-ethylhexyl di(p-tolyl) phosphate, bis(2-ethylhexyl)p-tolyl phosphate, trityl phosphate, di(dodecyl)p-tolyl phosphate, tris(2-butoxyethyl) phosphate, tricyclohexyl phosphate, triphenyl phosphate, ethyl diphenyl phosphate, and dibutyl phosphate. Phosphate esters such as phenyl phosphate, phenylbisdodecyl phosphate, cresyldiphenyl phosphate, tricresyl phosphate, p-tolylbis(2,5,5'-trimethylhexyl) phosphate, cresyl-2,6-xylenyl phosphate, trixylenyl phosphate, hydroxyphenyldiphenyl phosphate, tris(t-butylphenyl) phosphate, tris(i-propylphenyl) phosphate, 2-ethylhexyldiphenyl phosphate, bis(2-ethylhexyl)phenyl phosphate, tri(nonylphenyl) phosphate, phenylbisneopentyl phosphate, etc. Condensed phosphate esters such as 1,3-phenylene bis(diphenyl phosphate), 1,4-phenylene bis(dixylenyl phosphate), 1,3-phenylene bis(3,5,5'-trimethylhexyl phosphate), bisphenol A bis(diphenyl phosphate), 4,4'-biphenyl bis(dixylenyl phosphate), and 1,3,5-phenylene tris(dixylenyl phosphate) Phosphite esters such as trimethyl phosphite, triethyl phosphite, triphenyl phosphite, and tricresyl phosphite, Examples of phosphite esters include 1,3-phenylene bis(diphenyl phosphite), 1,3-phenylene bis(dixylenyl phosphite), 1,4-phenylene bis(3,5,5'-trimethylhexyl phosphite), bisphenol A bis(diphenyl phosphite), 4,4'-biphenyl bis(dixylenyl phosphite), and 1,3,5-phenylene tris(dixylenyl phosphite). Examples of germanium compounds include organic germanium compounds such as methylgermane, ethylgermane, trimethylgermanium methoxide, dimethylgermanium diacetate, tributylgermanium acetate, tetramethoxygermanium, tetraethoxygermanium, isobutylgermane, alkylgermanium trichloride, and dimethylaminogermanium trichloride. Examples of germanium complexes include nitrotriphenol complexes (Ge2(ntp)2O), catechol complexes (Ge(cat)2), or aminopyrene complexes (Ge2(ap)2Cl2), as well as germanium alkoxides such as germanium ethoxide and germanium tetrabutoxide.

[0040] Examples of tin compounds include inorganic tin compounds such as tin(II) oxide, tin(IV) oxide, tin(II) sulfide, tin(IV) sulfide, tin(II) chloride, tin(IV) chloride, tin(II) bromide, tin(II) fluoride, tin acetate, and tin sulfate; alkyl tin compounds such as tetramethyltin; monoalkyl tin oxide compounds such as monobutyltin oxide; dialkyl tin oxide compounds such as dibutyltin oxide; aryl tin compounds such as tetraphenyltin; and organotin compounds such as dimethyl tin maleate, hydroxybutyltin oxide, and monobutyltin tris(2-ethylhexanoate). Examples of nickel compounds include divalent nickel halides such as nickel(II) chloride, nickel(II) bromide, and nickel(II) iodide; inorganic nickel compounds such as nickel(II) acetate and nickel(II) carbonate; and organic nickel compounds such as nickelbis(ethyl acetate) and nickelbis(acetylacetonate).

[0041] Examples of titanium compounds include inorganic titanium compounds such as titanium dioxide, titanium nitride, strontium titanate, lead titanate, barium titanate, and potassium titanate; tetraalkoxy titanium compounds such as tetraethoxytitanium, tetraisopropoxytitanium, and tetrabutyroxytitanium; tetraethylene glycol titanate, di-n-butylbis(triethanolamine) titanate, diisopropoxytitanium bis(acetylacetone)ate, isopropoxytitanium octanoate, isopropyl titanium trimethacrylate, isopropyl titanium triacrylate, isopropyl triisostearoyl titanate, isopropyl tridecylbenzenesulfonyl titanate, isopropyl tris(butylmethyl pyrophosphate) titanate, tetraisopropyl di(dilauryl phosphite) titanate, dimethacrylate acetate titanate, diacryloxyacetate titanate, di(dioctyl phosphate)ethylene titanate, and tri (Dioctyl Phosphate) Isopropoxy Titanium, Isopropyl Tris(Dioctyl Pyrophosphate) Titanate, Tetraisopropyl Bis(Dioctyl Phosphate) Titanate, Tetraoctyl Bis(Ditridecyl Phosphate) Titanate, Tetra(2,2-Diallyloxymethyl-1-butyl) Bis(Di-Tridecyl) Phosphate Titanate, Bis(Dioctyl Pyrophosphate) Oxyacetate Titanate, Tris(Dioctyl Pyrophosphate) Ethyl Examples include organotitanium compounds such as lentaneate, isopropyl tri-n-dodecylbenzenesulfonyl titanate, isopropyl trioctanoyl titanate, isopropyl dimethacryloyl isostearoyl titanate, isopropyl isostearoyl diacrylic titanate, isopropyl tri(dioctyl phosphate) titanate, isopropyl tricumylphenyl titanate, and isopropyl tri(N-aminoethyl-aminoethyl) titanate.

[0042] Examples of cobalt compounds include inorganic cobalt compounds such as cobalt inorganic salts, cobalt halides, cobalt oxide, cobalt hydroxide, dicobalt octacarbonyl, cobalt hydrogen tetracarbonyl, tetracobalt dodecacarbonyl, alkylidine tricobalt nonacarbonyl, cobalt tris(ethyl acetate), cobalt tris(acetylacetonate), organic cobalt salts (e.g., acetate, propionate, cyanide, naphthenate, stearate; alkyl sulfonates such as methanesulfonate, ethanesulfonate, octanesulfonate, dodecanesulfonate, etc. 6-18 Alkyl sulfonates; Aryl sulfonates that may be substituted with alkyl groups such as benzenesulfonates, p-toluenesulfonates, naphthalenesulfonates, decylbenzenesulfonates, and dodecylbenzenesulfonates (e.g., C 6-18 Examples include alkyl-aryl sulfonates and organic cobalt complexes. Ligands that make up the complexes include OH (hydroxo), alkoxy (methoxy, ethoxy, propoxy, butoxy, etc.), acyl (acetyl, propionyl, etc.), alkoxycarbonyl (methoxycarbonyl, ethoxycarbonyl, etc.), acetylacetonate, cyclopentadienyl group, halogen atoms (chlorine, bromine, etc.), CO, CN, oxygen atom, H2O (ac), phosphorus compounds such as phosphine (triarylphosphine such as triphenylphosphine), NH3 (ammine), NO, NO2 (nitro), NO3 (nitrate), ethylenediamine, diethylenetriamine, pyridine, phenanthroline, and other nitrogen-containing compounds.

[0043] Examples of xenon compounds include fluorides such as XeF2, XeF4, XeF6, XeOF2, XeOF4, and XeO2F4; oxides such as XeO3 and XeO4; xenonic acid Xe(OH)6 and its salt Ba3XeO6; perxenonic acid H4XeO6 and its salt Na4XeO6; complexes with metal carbonyls M(CO)5Xe(M=Cr,Mo,W); and hydrates. Examples of chromium compounds include chromium acetylacetone complexes such as acetylacetone chromium, chromium alkoxides such as chromium(III) isopropoxide, organic acid chromium such as chromium(II) acetate and hydroxychromium(III) diacetate, tris(allyl)chromium, tris(methallyl)chromium, tris(clotyl)chromium, bis(cyclopentadienyl)chromium (i.e., chromosene), bis(pentamethylcyclopentadienyl)chromium (i.e., decamethylchromosene), bis(benzene)chromium, Examples of organochromium compounds include bis(ethylbenzene)chromium, bis(mesitylene)chromium, bis(pentadienyl)chromium, bis(2,4-dimethylpentadienyl)chromium, bis(allyl)tricarbonylchromium, (cyclopentadienyl)(pentadienyl)chromium, tetra(1-norbornyl)chromium, (trimethylenemethane)tetracarbonylchromium, bis(butadiene)dicarbonylchromium, (butadiene)tetracarbonylchromium, and bis(cyclooctatetraene)chromium.

[0044] Examples of tungsten compounds include inorganic tungsten compounds such as tungsten trioxide, ammonium tungstate, and sodium tungstate; boron atom-coordinated tungsten complexes such as those with ethylborylethylidene ligands; carbon atom-coordinated tungsten complexes such as those with carbonyl ligands, cyclopentadienyl ligands, alkyl ligands, and olefin ligands; nitrogen atom-coordinated tungsten complexes such as pyridine ligands and acetonitrile ligands; phosphorus atom-coordinated tungsten complexes coordinated with phosphine ligands, phosphine ligands, and phosphite ligands; and organic tungsten compounds such as sulfur atom-coordinated tungsten complexes coordinated with diethylcarbamodithiolat ligands. Examples of thallium compounds include inorganic thallium compounds such as thallium nitrate, thallium sulfate, thallium fluoride, thallium chloride, thallium bromide, and thallium iodide; trialkylthallium compounds such as trimethylthallium, triethylthallium, and triisobutylthallium; arylthallium compounds such as dialkylthallium halides, alkenyldialkylthallium, alkynyldialkylthallium, triphenylthallium, and tritolylthallium; diarylthallium halides; thallium 2-ethylhexanoate, thallium malonate, thallium formate, thallium ethoxide, and thallium acetylacetonate.

[0045] Examples of zirconium compounds include inorganic zirconium compounds such as zirconium nitrate, zirconium sulfate, zirconium carbonate, zirconium hydroxide, zirconium fluoride, zirconium chloride, zirconium bromide, and zirconium iodide, as well as organic zirconium compounds such as zirconium n-propoxide, zirconium n-butoxide, zirconium t-butoxide, zirconium isopropoxide, zirconium ethoxide, zirconyl acetate, zirconium acetylacetonate, zirconium butoxyacetylacetonate, zirconium bisacetylacetonate, zirconium ethylacetoacetate, zirconium acetylacetonate bisethylacetoacetate, zirconium hexafluoroacetylacetonate, and zirconium trifluoroacetylacetonate. Examples of zinc compounds include diethylzinc, dimethylzinc, zinc acetate, zinc nitrate, zinc stearate, zinc oleate, zinc palmitate, zinc myristate, zinc dodecanoate, zinc acetylacetonate, zinc chloride, zinc bromide, zinc iodide, and zinc carbamate.

[0046] Examples of silver compounds include organosilver compounds such as silver acetate, silver pivalate, silver trifluoromethanesulfonate, and silver benzoate; and inorganic silver compounds such as silver nitrate, silver fluoride, silver chloride, silver bromide, silver iodide, silver sulfate, silver oxide, silver sulfide, silver tetrafluoroborate, silver hexafluorophosphate (AgPF6), and silver hexafluoroantimonate (AgSbF6). Examples of lead compounds include lead monoxide (PbO), lead dioxide (PbO2), red lead (Pb3O4), lead white (2PbCO3·Pb(OH)2), lead nitrate (Pb(NO3)2), lead chloride (PbCl2), lead sulfide (PbS), lead yellow (PbCrO4, Pb(SCr)O4, PbO·PbCrO4), lead carbonate (PbCO3), lead sulfate (PbSO4), and lead fluoride (P Examples include inorganic lead compounds such as lead bF2, lead tetrafluoride (PbF4), lead bromide (PbBr2), and lead iodide (PbI2), and organic lead compounds such as lead acetate (Pb(CH3COO)2), lead tetracarboxylate (Pb(OCOCH3)4), tetraethyl lead (Pb(CH3CH2)4), tetramethyl lead (Pb(CH3)4), and tetrabutyl lead (Pb(C4H9)4).

[0047] Examples of aluminum compounds include inorganic aluminum compounds such as aluminum oxide, alkoxy compounds such as trimethoxyaluminum, triethoxyaluminum, isopropoxyaluminum, isopropoxydiethoxyaluminum, and tributoxyaluminum; acyloxy compounds such as triacetoxyaluminum, tristearatealuminum, and tributyratealuminum; aluminum isopropylate, aluminum sec-butyrate, aluminum tert-butyrate, aluminum tris(ethylacetate), tris(hexafluoroacetylacetonate)aluminum, tris(ethylacetate), and tris(n-propylacetate). Examples include trialkylaluminum compounds such as trimethylaluminum, triethylaluminum, triisobutylaluminum, tris(isopropylacetate)aluminum, tris(n-butylacetate)aluminum, trissalicyaldehydealuminum, tris(2-ethoxycarbonylphenolate)aluminum, tris(acetylacetonate)aluminum, trimethylaluminum, triethylaluminum, triisobutylaluminum, arylaluminum compounds such as dialkylaluminum halides, alkenyldialkylaluminum, alkynyldialkylaluminum, triphenylaluminum, tritolylaluminum, and diarylaluminum halides.

[0048] Examples of vanadium compounds include vanadic acid and metavanadic acid, as well as their alkali metal salts (inorganic vanadium compounds), alkoxides such as triethoxyvanadyl, pentaethoxyvanadium, triamyloxyvanadyl, and triisopropoxyvanadyl; acetonates such as bisacetylacetonate vanadyl, vanadium acetylacetonate, vanadyl acetylacetonate, and vanadium oxyacetylacetonate; and organic vanadium compounds such as vanadium stearate, vanadium pivalate, and vanadium acetate. Examples of niobium compounds include halides such as niobium pentachloride and niobium pentafluoride, inorganic niobium compounds such as niobium sulfate, niobic acid, and niobate salts, and organic niobium compounds such as niobium alkoxides.

[0049] Examples of tantalum compounds include inorganic tantalum compounds such as TaCl5 and TaF5, and organic tantalum compounds such as Ta(OC2H5)5, Ta(OCH3)5, Ta(OC3H7)5, Ta(OC4H9)5, (C5H5)2TaH3, and Ta(N(CH3)2)5. Examples of molybdenum compounds include inorganic molybdenum compounds such as molybdenum trioxide, zinc molybdate, ammonium molybdate, magnesium molybdate, calcium molybdate, barium molybdate, sodium molybdate, potassium molybdate, phosphomolybdate, ammonium phosphomolybdate, sodium phosphomolybdate, silicic acid, molybdenum disulfide, molybdenum diselenium, molybdenum ditelluride, molybdenum boride, molybdenum disilicate, molybdenum nitride, and molybdenum carbide, as well as organic molybdenum compounds such as molybdenum dialkyldithiophosphate and molybdenum dialkyldithiocarbamate. Examples of manganese compounds include inorganic manganese compounds such as manganese hydroxide, nitrate, acetate, sulfate, chloride, and carbonate; manganese oxalate, acetylacetonate compounds; and organic manganese compounds including manganese alkoxides such as methoxide, ethoxide, and butoxide.

[0050] Examples of iron compounds include iron(II) fluoride, iron(III) fluoride, iron(II) chloride, iron(III) chloride, iron(II) bromide, iron(III) bromide, and iron(II) iodide. Inorganic iron compounds such as iron(III) iodide, iron(II) oxide, iron(III) oxide, triiron(II, III) tetroxide, iron(II) sulfate, iron(III) sulfate, iron(II) nitrate, iron(III) nitrate, iron(II) hydroxide, iron(III) hydroxide, iron(II) perchlorate, iron(III) perchlorate, iron(II) ammonium sulfate, iron(III) ammonium sulfate, iron(III) tungstate, iron(III) tetravanadate, iron(II) selenide, iron(II) titanium trioxide, iron(III) titanium pentoxide, iron(II) sulfide, iron(III) sulfide, iron(II) phosphide, triiron(II) phosphide, iron(III) phosphide; iron(II) acetate, iron(III) acetate, iron(II) formate, iron(III) triformate, iron(II) tartrate. Examples of organic iron compounds include sodium ferric tartrate, ferric lactate, ferric oxalate, ferric oxalate, ferric ammonium citrate, ferric laurate, ferric stearate, ferric tripalmitate, potassium hexacyanoferrate(II), potassium hexacyanoferrate(III), bis(2,4-pentanedionato)diaferrate(II), tris(2,4-pentanedionato)ferrate(III), potassium tris(oxalato)ferrate(III), tris(trifluoromethanesulfonic acid)ferrate(III), p-toluenesulfonate ferric dimethyldithiocarbamate, diethyldithiocarbamate ferric

[0051] Examples of copper compounds include organocopper compounds such as copper oxalate, copper stearate, copper formate, copper tartrate, copper oleate, copper acetate, copper gluconate, and copper salicylate, as well as inorganic copper compounds such as copper carbonate, copper chloride, copper bromide, copper iodide, copper phosphate, hydrotalcite, stichtite, and pyrolite. Examples of cadmium compounds include inorganic cadmium compounds such as cadmium fluoride, cadmium chloride, cadmium bromide, cadmium iodide, cadmium oxide, and cadmium carbonate, as well as organic cadmium compounds such as cadmium phthalate and cadmium naphthalate.

[0052] Examples of mercury compounds include inorganic mercury compounds such as mercuric chloride, mercuric sulfate, and mercuric nitrate, and organic mercury compounds such as methylmercury, methylmercury chloride, ethylmercury, ethylmercury chloride, phenylmercury acetate, thimerosal, mercury parachlorobenzoate, and fluorescein mercury acetate. Examples of gallium compounds include organic gallium compounds such as tetraphenylgallium and tetrakis(3,4,5-trifluorophenyl)gallium, and inorganic gallium compounds such as gallium oxoate, gallium halide, gallium hydroxide, and gallium cyanide. Examples of indium compounds include organic indium compounds such as triethoxyindium, indium 2-ethylhexanoate, and indium acetylacetonate, and inorganic indium compounds such as indium cyanide, indium nitrate, indium sulfate, indium carbonate, indium fluoride, indium chloride, indium bromide, and indium iodide.

[0053] Examples of arsenic compounds include inorganic arsenic compounds such as arsenic trioxide, arsenic pentoxide, arsenic trichloride, arsenic pentachloride, arsenous acid, arsenic acid, and their salts, such as sodium arsenous acid, ammonium arsenous acid, potassium arsenous acid, ammonium arsenate, and potassium arsenate; and organic arsenic compounds such as cacodylic acid, phenylarsonic acid, diphenylarsonic acid, p-hydroxyphenylarsonic acid, p-aminophenylarsonic acid, and their salts, such as sodium cacodylate and potassium cacodylate. Examples of antimony compounds include inorganic antimony compounds such as antimony oxide, antimony phosphate, KSb(OH), and NH4SbF6, as well as organic antimony compounds such as antimony esters with organic acids, cyclic alkyl antimonite esters, and triphenylantimony. Examples of bismuth compounds include organic bismuth compounds such as triphenylbismuth, bismuth 2-ethylhexanoate, and bismuth acetylacetonate, and inorganic bismuth compounds such as bismuth nitrate, bismuth sulfate, bismuth acetate, bismuth hydroxide, bismuth fluoride, bismuth chloride, bismuth bromide, and bismuth iodide.

[0054] Examples of selenium compounds include organic selenium compounds such as selenomethionine, selenocysteine, and selenocystin, as well as inorganic selenium compounds including alkali metal selenates such as potassium selenate and alkali metal selenites such as sodium selenite. Examples of tellurium compounds include telluric acid and its salts, tellurium oxide, tellurium chloride, tellurium bromide, tellurium iodide, and tellurium alkoxides. Examples of magnesium compounds include organomagnesium compounds such as ethyl acetacetate magnesium monoisopropylate, magnesium bis(ethyl acetacetate), alkyl acetacetate magnesium monoisopropylate, and magnesium bis(acetylacetonate), as well as inorganic magnesium compounds such as magnesium oxide, magnesium sulfate, magnesium nitrate, and magnesium chloride.

[0055] Examples of calcium compounds include organocalcium compounds such as calcium 2-ethylhexanoate, calcium ethoxide, calcium methoxide, calcium methoxyethoxide, and calcium acetylacetonate, as well as inorganic calcium compounds such as calcium nitrate, calcium sulfate, calcium carbonate, calcium phosphate, calcium hydroxide, calcium cyanide, calcium fluoride, calcium chloride, calcium bromide, and calcium iodide. For heteroatom compounds containing different atoms such as Li, Na, K, Cs, S, Sr, Ba, F, Y, and lanthanides, known organic or inorganic compounds can be used. Heteratomic compounds may be used individually or in combination of two or more.

[0056] The proportion of explosives in a mixture containing explosives and heteroatomic compounds is preferably 80-99.9999% by mass, more preferably 85-99.999% by mass, even more preferably 90-99.99% by mass, and particularly preferably 95-99.9% by mass. The proportion of heteroatomic compounds is preferably 0.0001-20% by mass, more preferably 0.001-15% by mass, even more preferably 0.01-10% by mass, and particularly preferably 0.1-5% by mass. The heteroatomic content in the mixture containing explosives and heteroatomic compounds is preferably 0.000005-10% by mass, more preferably 0.00001-8% by mass, even more preferably 0.0001-5% by mass, particularly preferably 0.001-3% by mass, and most preferably 0.01-1% by mass. The mixing of explosives and heteroatomic compounds can be done by powder mixing, melting, or dissolving or dispersing them in a suitable solvent if both are solids. Mixing can be carried out by stirring, bead milling, ultrasound, etc.

[0057] In one preferred embodiment, the explosive composition comprising the explosive and the heteroatomic compound further comprises a cooling medium. The cooling medium may be a solid, liquid, or gas. One method of using the cooling medium is to detonate the mixture of the explosive and the heteroatomic compound in the cooling medium. Examples of cooling mediums include inert gases (nitrogen, argon, CO), water, ice, liquid nitrogen, aqueous solutions of heteroatom-containing salts, and crystalline hydrates. Examples of heteroatom-containing salts include ammonium hexafluorosilicate, ammonium silicate, and tetramethylammonium silicate. When using water or ice, for example, it is preferable to use about five times the weight of the explosive as the cooling medium.

[0058] In one preferred embodiment of the present invention, a mixture containing an explosive and an heteroatomic compound is converted into diamond by compression due to a shock wave under high pressure and high temperature conditions generated by the explosion of the explosive (detonation method). Heteroatoms are incorporated into the diamond lattice during the explosion of the explosive. The carbon source of the nanodiamonds may be the explosive and the organic heteroatomic compound, but if the mixture containing the explosive and the heteroatomic compound further contains a carbon material that does not contain heteroatoms, this carbon material can also serve as a carbon source for the nanodiamonds. The Si-doped nanodiamond particles of the present invention can be manufactured using a Si compound as the heteroatom compound, according to the manufacturing method of the present invention. [Examples]

[0059] The present invention will be described more specifically below with reference to examples, but the present invention is not limited to these examples. (A) Method for measuring fluorescence ND (I) Sample preparation • Disperse the nanodiamond powder in water to prepare a slurry. The concentration is 1% by mass. Take 1 μL of nanodia slurry, drop it onto a coverslip, and dry at room temperature. After drying, the sample will form a round shape on the surface of the coverslip. Perform fluorescence measurement in this state. (II) Fluorescence measurement • Sample set The sample is placed in the micro-Raman spectrometer, and the measurement is performed using a 100x objective lens. The lens is focused on the sample surface, and then the excitation laser (532 nm) is also focused on the sample surface.

[0060] (B) Setting of measurement conditions The mapping measurement is performed using the "Swift" function attached to the micro-Raman spectrometer. Setting the range of the measured fluorescence spectrum: In the case of SIV, the width is 100nm from 700nm to 800nm. For GeV, the width is 100nm from 580nm to 680nm. Within this 100nm width, the entire spectrum, including ZPLs and sidebands, can be obtained. Sample measurement area setup: 100 μm x 100 μm. Fluorescence is measured in 1 μm increments while moving horizontally. The instrument's software measures a total of 10201 points (101 points x 101 points). Measurements were taken at three points on the round sample: the center, the middle, and the outer edge. Laser wavelength: 532nm After the measurement is complete, 10,201 fluorescence spectra are obtained, and these spectra are then analyzed.

[0061] (C) Method for analyzing the measurement results of fluorescence ND (I) Acquisition of fluorescence images This method uses the fluorescence intensity values ​​within a certain range of the fluorescence spectrum to display an image with corresponding brightness levels. This fluorescence image allows for a rough estimate of the amount of SiV or GeV to be prepared. For SiV, the fluorescence intensity value is used within the range of 738nm ± 0.5nm. For GeV, the fluorescence intensity value is used within the range of 602nm ± 0.5nm. (II) Calculation of the proportion of bright spots with and without ZPL The software for the micro-Raman spectrometer has a spectral shape recognition function, which can be used to distinguish between the presence and absence of a zero-phase line (ZPL). While the ZPL may shift due to the structure of the fluorescence center, this shape recognition function allows for determination of ZPL presence or absence even with slight shifts. The spectral shape needs to be set for ZPL recognition, but wavelength setting is not required. Using software, it's possible to count points with ZPLs as bright spots and calculate their proportion.

[0062] Example 1 Approximately 1 kg of an explosive composition containing 100 parts by mass of an explosive containing trinitrotoluene (TNT) and cyclotrimethylenethrinitolamine (RDX), with 1 part by mass of triphenylsilanol added as a heteroatom compound, was used to produce silicon-doped nanodiamonds according to a conventional method for nanodiamond production. The obtained silicon-doped nanodiamonds were subjected to the following treatments. The amount of triphenylsilanol added to the explosive was 1% by mass. (i) Mixed acid treatment 2800g of a mixed acid in a concentrated sulfuric acid:concentrated nitric acid ratio of 11:1 (by weight) was mixed with 15g of nanodiamonds obtained from a detonation test, and the mixture was treated at 150°C for 10 hours while stirring. (ii) Alkali treatment 1 g of mixed acid-treated nanodiamonds was added to 100 mL of 8N sodium hydroxide aqueous solution and treated at 70°C for 8 hours while stirring. The obtained Si-doped nanodiamond raw material was oxidized in a gas atmosphere furnace at 570°C in a 4% oxygen atmosphere for 2 hours to obtain the Si-doped nanodiamond particles of the present invention. The yield after the 570°C oxidation treatment was 4.6%.

[0063] Example 2 The Si-doped nanodiamond particles obtained in Example 1 were further subjected to hydrogenation treatment at 550°C in a 2% hydrogen atmosphere for 5 hours. The yield after hydrogenation treatment at 550°C was 93.5%, and the yield after oxidation treatment at 570°C was 4.6%, so the total yield from oxidation treatment at 570°C + hydrogenation treatment at 550°C was 4.3%.

[0064] Comparative Examples 1-3 Si-doped nanodiamond particles were obtained in the same manner as in Example 1, except that the oxidation treatment in Example 1 was performed at 470°C for 0 hours (before oxidation treatment, Comparative Example 1), 0.5 hours (Comparative Example 2), or 2 hours (Comparative Example 3).

[0065] Test Example 1 For the Si-doped nanodiamond particles obtained in Examples 1-2 and Comparative Examples 1-3, high-speed mapping and 738nm bright spot imaging were performed using a micro-Raman spectrometer (product name: Micro-Laser Raman Spectrophotometer LabRAM HR Evolution, manufactured by Horiba, Ltd.), and fluorescence intensity and number of bright spots (center, intermediate layer, outer periphery) were measured. Furthermore, the average size of the primary particles was measured based on Scherrer's formula using powder X-ray diffraction (XRD) with a fully automated multi-purpose X-ray diffractometer (manufactured by Rigaku Corporation). In addition, the amount of Si introduced was measured by XRF using a fluorescence X-ray analyzer ZSX Primus IV (manufactured by Rigaku Corporation). Furthermore, sp 2 Carbon and sp 3 The peak area ratio of carbon was measured by micro-Raman spectroscopy using a micro-Raman spectrometer (product name: Micro-Laser Raman Spectrophotometer LabRAM HR Evolution, manufactured by Horiba, Ltd.). A 325 nm laser was used for the measurement, and sp 2 The peak area for carbon is 1250 cm². -1 and 1328cm -1 Refer to the area of ​​the peaks appearing nearby, sp 3 The peak area for carbon is 1500 cm². -1 and 1590cm -1 The area of ​​the peaks appearing in the vicinity was referenced. The results are shown in Figures 1-2 and Tables 1-2.

[0066] [Table 1]

[0067] [Table 2]

[0068] Example 3 Ge-doped nanodiamond particles were obtained in the same manner as in Example 1, except that 1 part by mass of tetraphenylgermane was used instead of 1 part by mass of triphenylsilanol, and the oxidation treatment was carried out at 520°C for 2 hours.

[0069] Comparative Example 4 Ge-doped nanodiamond particles were obtained in the same manner as in Example 3, except that the oxidation treatment in Example 3 was carried out at 470°C for 2 hours.

[0070] Test Example 2 For the Ge-doped nanodiamond particles obtained in Example 3 and Comparative Example 4, high-speed mapping and 602nm bright spot imaging were performed using a micro-Raman spectrometer (product name: Micro-Laser Raman Spectrophotometer LabRAM HR Evolution, manufactured by Horiba, Ltd.), and fluorescence intensity and the number of bright spots (center) were measured. The results are shown in Figures 3-4 and Table 3. The percentage of bright spots emitting fluorescence at approximately 602nm in the ZPL of the Ge-V center was 100 × 6283 ÷ 10201 = approximately 61.6%.

[0071] [Table 3]

Claims

1. Heteratom-doped nanodiamond particles having fluorescence emission peaks originating from heteroatom-Vacancy (heteratom-V) centers that satisfy the following conditions (i) to (ii): (i) When 1 μL of a 1% by mass aqueous suspension of the particles is dropped onto a glass substrate and a fluorescence spectrum is acquired using a micro-Raman spectrometer for 10¹ × 10¹ points in a sample area of ​​100 μm × 100 μm with a spatial resolution of 1 μm, the proportion of bright spots emitting fluorescence at the ZPL peak in ZPL ± X nm (0 ≤ X ≤ 5) of heteroatom-V centers is 50% or more. (ii) The average size of the primary particles is 2 to 70 nm.

2. The heteroatom-doped nanodiamond particle according to claim 1, wherein the heteroatom is a Group 14 element selected from the group consisting of Si, Ge, Sn, and Pb.

3. The heteroatom-doped nanodiamond particles according to claim 1 or 2, wherein (i) when 1 μL of a 1 mass% aqueous suspension of the particles is dropped onto a glass substrate and a fluorescence spectrum is acquired using a micro-Raman spectrometer with a spatial resolution of 1 μm and excitation light of 532 nm for 10¹ × 10¹ points in a sample area of ​​100 μm × 100 μm, the proportion of bright spots emitting fluorescence at the ZPL peak of the Si-V center at 738 nm ± X nm (0 ≤ X ≤ 5) is 50% or more.

4. The heteroatom-doped nanodiamond particles according to claim 1 or 2, wherein (i) when 1 μL of a 1 mass% aqueous suspension of the particles is dropped onto a glass substrate and a fluorescence spectrum is acquired using a micro-Raman spectrometer with a spatial resolution of 1 μm and excitation light of 532 nm for 10¹ × 10¹ points in a sample area of ​​100 μm × 100 μm, the proportion of bright spots emitting fluorescence at the ZPL peak of the Ge-V center at 602 nm ± X nm (0 ≤ X ≤ 5) is 50% or more.

5. sp obtained from the aforementioned particles by Raman spectroscopy 2 Carbon and sp 3 Carbon peak area ratio (sp 2 carbon / sp 3 Heteratomic doped nanodiamond particles according to any one of claims 1 to 4, wherein the carbon content is 0.01 to 7.

0.

6. Heteratomic doped nanodiamond particles according to any one of claims 1 to 5, satisfying the following conditions (a) and / or (b): (a) The zeta potential of the particle is between -70mV and 70mV. (b) The pH of the particles when dispersed in water at a concentration of 3 wt% is between 1 and 12.

7. The heteroatom-doped nanodiamond particle according to any one of claims 1 to 6, wherein the shape of the particle is spherical, ellipsoidal, or polyhedral.

8. The BET specific surface area of ​​the aforementioned particles is 20 to 900 m². 2 Heteratomic doped nanodiamond particles according to any one of claims 1 to 7, wherein the particle size is / g.

9. The heteroatom-doped nanodiamond particles according to any one of claims 1 to 8, wherein the proportion of the number of bright spots is 90% or more.

10. A method for producing heteroatom-doped nanodiamond particles, comprising treating a heteroatom-doped nanodiamond raw material produced by detonation with the following (I) and / or (II): (I) Oxidation treatment at 500-650°C, (II) Hydrogenation treatment at 300-1200°C.

11. The manufacturing method according to claim 10, wherein the oxidation treatment is carried out in an atmosphere with an oxygen concentration of 1 to 100%.

12. The manufacturing method according to claim 10, wherein the hydrogenation treatment is carried out in an atmosphere with a hydrogen concentration of 1 to 100%.

Images