JP2002097009A - Hybrid single-walled carbon nanotube - Google Patents

Abstract

(57) [Abstract] (Modified) [Problem] A new hybrid single-walled carbon that has the potential to be used in a wide range of fields such as information and communication and the chemical industry, because various substances can be included in the space inside the cylinder. Provide nanotubes. SOLUTION: A metal, an organic molecule, an organometallic compound, a magnetic material, a semiconductor,
A hybrid single-walled carbon nanotube in which one or more kinds of different substances among a complex, a gas, an inorganic solid compound and the like are included. Lead, tin,
Copper and the like, naphthalene and anthracene as organic substances, samarium and iron as magnetic substances, and carbon oxide and the like as gas.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a hybrid single-walled carbon nanotube. More specifically, the invention of this application relates to a new hybrid single-walled carbon nanotube capable of encapsulating various substances in the space inside the cylinder and having potential for use in a wide range of fields such as information communication and the chemical industry. It is.

[0002]

2. Description of the Related Art Carbon nanotubes are attracting attention as next-generation high-performance materials in a wide range of fields such as the energy field, information communication, aviation / space, biological / medical fields, and the like. This carbon nanotube has
The graphite sheet forming the tube is a single layer,
There are so-called single-walled carbon nanotubes (SWNTs) and multi-walled carbon nanotubes (MWNTs) in which many graphite sheet cylinders are nested. In research and development to efficiently apply the electron emission function, hydrogen storage function, magnetic function, etc. of carbon nanotubes, SWNTs are mainly used due to the simplification of the structure of carbon nanotubes and their unique properties. . In recent years, there has been a discussion of creating a new chemically or physically modified nanocomposite material by variously processing SWNT.

[0003] Specifically, the possibility that the electrical and mechanical characteristics of SWNT itself can be changed to something completely different,
The introduction of various atoms, molecules, and the like into the voids in the cylinder of NT has been discussed, and research has been advanced. And SW
C ₆₀ ＠SWN in which C ₆₀ molecules are encapsulated in the cavity in the cylinder of NT
T (the symbol ＠ generally means inclusion) has already been discovered. In addition, the inventors of the present application have proposed a multi-walled carbon nanotube containing a foreign substance and a method for producing the same (Japanese Patent Application No. 4-341747).

[0004] However, at present, a new material based on SWNT, in which various substances are included in the cavity in the cylinder, and a manufacturing technique thereof have not yet been known.

Accordingly, the invention of this application has been made in view of the circumstances described above, and it is possible to include various substances in the space inside the cylinder and use it in a wide field such as information communication and chemical industry. It is an object of the present invention to provide a new hybrid single-walled carbon nanotube that has the potential to be used.

[0006]

Accordingly, the invention of this application provides the following invention to solve the above problems.

That is, first of all, the invention of the present application provides a hybrid single-walled carbon nanotube characterized in that a foreign substance is included in a cylindrical space of the single-walled carbon nanotube.

Secondly, the invention of this application is based on the first invention, wherein the foreign substances included are metals, organic molecules, organometallic compounds, magnetic substances, semiconductors, superconductors, complexes, and gases. Third, the hybrid single-walled carbon nanotube is characterized by being one or more of inorganic solid compounds. Thirdly, the foreign substance included is a metal-encapsulated fullerene. Fourthly, the present invention also provides a hybrid single-walled carbon nanotube in which the foreign substance contained therein is a toxic gas.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The invention of this application has the features as described above, and embodiments thereof will be described below.

[0010] First, the hybrid single-walled carbon nanotube provided by the invention of this application is characterized in that a foreign substance is included in the cavity in the cylinder of SWNT.

As the substance to be included, any one or more of metals, organic molecules, organometallic compounds, magnetic substances, semiconductors, superconductors, complexes, gases, inorganic solid compounds and the like are selected. Can do things.

For example, the metals include various metals such as lead, tin, copper, indium, mercury, alkali metals and transition metals and their compounds, and the organic molecules include aromatics such as naphthalene, anthracene, phenanthrene, pyrene and perylene. Compounds, organic molecular semiconductors, and organic dye molecules such as cyanine dyes and beta carotene; carbon clusters such as fullerene and superfullerene; metal-encapsulated fullerenes in which these include metal atoms; and ferrocene. An organometallic compound or the like can be used.
Elements such as samarium, gadolinium, lanthanum, iron, cobalt, nickel, and mixtures thereof are used as magnetic materials, silicon, germanium, gallium arsenide, zinc selenide, zinc sulfide, etc. as semiconductors, and superconductors. Elements such as lead, tin, and gallium, and organometallic and inorganic metal complexes, hydrogen, boron, nitrogen, and oxygen can be used. Gases such as carbon oxide, nitric oxide, inert gas or toxic gas, silane,
Disilane, germane, dichlorosilane, arsine, phosphine, hydrogen selenide, hydrogen sulfide, triethylgallium, dimethyl zinc, hexafluorotungsten, etc.
It is also possible to use hydrides, chlorides, fluorides, alkoxy compounds, alkyl compounds and gaseous substances comprising a combination thereof of the desired element.

Among the above substances, the metal-encapsulated fullerene is a semiconductor having a narrow band gap different from the C ₆₀ molecule, and it is known that the band gap takes various values depending on the number of metal atoms included therein. ing. If such a metal-encapsulated fullerene can be included in SWNT, a more interesting composite material will be provided.

The hybrid single-walled carbon nanotube of the invention of this application has a structure in which the above-mentioned foreign substances are arranged in a cavity in the SWNT cylinder in a state like beans in a pod. Since this foreign substance is relatively stably disposed in the SWNT, there is a high possibility that even a substance which has been unstable in the air conventionally can be stably stored or used. May be available.

Hereinafter, embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

[0016]

EXAMPLES (Example 1) Starting materials Gd @ C ₈₂ and S
WNT is sealed in a glass ampoule at 500 ° C for 2 hours.
4 hours, and the reaction product (G
d ＠ C ₈₂ ) _n ＠SWNT was obtained.

Using the obtained (Gd @ C ₈₂ ) _n @SWNT as a sample, observation was performed with a high-resolution transmission electron microscope (HRTEM) equipped with an electron energy loss spectrometer. The sample was dispersed in hexane by ultrasonication, and the suspension was dropped on a microgrid of an electron microscope to obtain a sample.
Image observation was performed at a setting of kV, and spectral measurement was performed at a setting of 117 kV. <A> FIGS. 1A and 1B show that (Gd ＠ C ₈₂ ) _n ＠SW
The HRTEM image of NT was illustrated. FIG. 1C illustrates a structural model of (Gd @ C ₈₂ ) _n @SWNT.

FIG. 1A shows that Gd is contained in SWANTs.
@C ₈₂ was found to be aligned in a row in a chain. The diameter of SWNT in a state in which the metal-encapsulated fullerene connected in a chain was further included was 1.4 to 1.5 nm.

As shown in FIG. 1 (a), a dark portion was found inside most of the _C82 molecular shell. Since this dark part is not observed in the case of _C60 molecules that do not include anything in the fullerene cage, it can be said that they correspond to Gd atoms included in _C82 molecules. From this, Gd
Without @C ₈₂ molecule decomposition or reaction, was found to be intact encapsulated in SWNT.

The Gd atom in the fullerene cage included in SWNT was located at a position shifted from the center of the fullerene cage _C82 molecule. Then, since the metal atoms included in the fullerene cage appear at certain positions, it was also confirmed that the fullerene cage included in SWNT did not rotate at room temperature.

As shown in FIG. 1B, a bundle of SWNs
T is also large, and the center-to-center distance between the tubes (Fig. 1
The average of (corresponding to d in (c)) was 1.64 nm or less. <B> FIG. 2A shows an HRTEM image of a bundle (Gd @ C ₈₂ ) _n @SWNT composed of several hundred SWNTs.
Although there was a bundle of SWNTs with empty cylinders, almost all bundles of SWNTs filled Gd ＠ C
It was confirmed that it contained ₈₂ . These were also proved by the electron diffraction pattern of a bundle of SWNTs as exemplified in FIG. 2B, for example.

Further, from the electron diffraction image of FIG. 2 (b), can be observed a sharp line to make stripes perpendicular to the axis of the nanotube bundles, which intermolecular Gd @ C ₈₂ molecules adjacent to each other It was confirmed that the intermolecular distance between the Gd @ C ₈₂ molecules was uniform in each SWNT bundle. This means that, as shown in FIG.
It was also confirmed by analyzing the M image by Fourier transform. The rings seen in both patterns correspond to reflections (〜0.214 nm) from the graphite (100) plane. The points arranged perpendicular to the axis of the bundle of SWNTs are the center-to-center distances of the hexagonal closest packed SWNTs (d).
It corresponds to.

Since the Gd @ C ₈₂ molecules in the SWNT are arranged at a certain intermolecular distance, the chain Gd @ C ₈₂ contained in the SWNT can be regarded as a one-dimensional crystal. When the interatomic distance (a) is measured, 1.1
0 ± 0.03 nm. Three-dimensional molecular interatomic distance of the crystal to be the results of synchrotron X-ray diffraction analysis to have a C _2V type molecular symmetry (e.g., Sc endohedral S
(c ＠ C ₈₂ , 1.124 nm), or slightly smaller. Note that the C ₆₀ and C ₇₀ in the SWNT which can be regarded as similarly one-dimensional crystal, and ~0.97nm respectively, were ～1.02Nm. <C> It was confirmed that Gd @ _C82 was introduced into the SWNT located at the center of the SWNT bundle, similarly to the SWNTs located at the periphery. This was confirmed for all other inclusions. Since it is unlikely that the encapsulated material will diffuse from the SWNTs outside the bundle to the central SWNTs, the inclusion of the encapsulated material is likely to occur at the capped SWNT end. <D> The results of analyzing several bundles of (Gd @ C ₈₂ ) _n @SWNT by electron energy loss spectroscopy are shown in FIG. FIG. 3A shows the N (4d) absorption edge of Gd (ｄ1).
45 eV) and the K (1s) absorption edge of carbon (up to 285 e)
V) was confirmed. Since the K (1s) absorption edge of carbon is due to both fullerene and SWNT carbon,
A sharp peak of π ^* bond and a broad peak of σ ^* bond were shown around 299 eV.

By averaging the two absorption edges of N (4d) and K (1s) using an appropriate scattering cross section, Gd
And the atomic ratio (Gd / C) of C and C is approximately 0.0025 (±
0.00047). This value is, as can be seen from the above observations, the value of S of 1.4 nm in diameter.
This is a value very close to the calculated value 0.0037 obtained for ₍ GdＧC ₈₂ ) _n ＠SWNT in which Gd ＠ C ₈₂ is arranged at an interatomic distance of 1.1 nm in WNT. Then, from this, the (Gd @ C ₈₂ ) _n @SWNT used in this observation was used.
The loading of Gd @ C _{82 in} the bundle was estimated to be approximately 68%.

FIG. 3B shows the M (3d) absorption edge of Gd obtained from the same sample as described above. In general, the M (3d) peak position of a lanthanoid metal can be used to identify the valence state, and the transfer amount can be known from the result. From FIG. 4B, (Gd _{ C ₈₂ ) _n}
The highest peak position in the M ₅ and M ₄ absorption edge of the SWNT were respectively 1184eV and 1214EV. Since these peak positions completely match the peak positions of Gd ₂ O ₃ which is a reference spectrum, (Gd ＠ C ₈₂ )
It was proved that the Gd atom included in _n @ SWNT was in a trivalent state. On the other hand, it has already been confirmed that the Gd atom contained in the Gd ³⁺ ＠C ₈₂ ^3- bulk crystal has the same spin state ( ⁸ S _7/2 ) as the Gd atom of Gd ₂ O ₃ . From these facts, the valence state of the Gd atom included in Gd @ C ₈₂ does not change before and after being included in SWNT, and is, for example, a state of (Gd ³⁺ @C ₈₂ ^3- ) _n @SWNT. You can see that. <E> Although the valence state of the C ₈₂ fullerene gauge in (Gd ＠ C ₈₂ ) _n ＠SWNT has not been clarified even now, from the above results, the Gd atom is converted to the fullerene cage or SWNT. The possibility of charge transfer was suggested. In TEM observation, for example, (C ₆₀ )
than _n AttoSWNT and (C ₇₀₎ SWNT containing therein the fullerenes have not containing a metal as such _{n @SWNT,}
It was found that (Gd @ C ₈₂ ) _n @SWNT was more easily broken by electron beam irradiation. These are important findings about the chemical properties of nanotubes containing metal-encapsulated fullerenes. (Example 2) As foreign substances included, Sm ＠ C ₈₂ , S
_{c 2 @C 84, La 2 @C} 80, Sc 3 N @ or metal-encapsulated fullerene such as _{C 68, C 70, C 76} , C 80, C 82, hollow fullerene such as C _84, various materials such as ferrocene It was also confirmed that hybrid carbon nanotubes containing these foreign substances could be obtained in the case of using.

Of course, the present invention is not limited to the above-described example, and it goes without saying that various aspects of the details are possible.

[0027]

As described in detail above, according to the present invention, various substances can be included in the cavity inside the cylinder,
A new hybrid single-walled carbon nanotube with potential for use in a wide range of fields such as information and communication and the chemical industry is provided.

[Brief description of the drawings]

FIG. 1. (a) shows isolated (Gd @ C ₈₂ ) _n @SWN
(B) shows a bundle of (Gd ＠ C ₈₂ ) _n ＠SWNT H
It is the figure which illustrated the RTEM image. (C) is a SWNT containing a metal-encapsulated fullerene (Gd _{ C ₈₂ ) _n}
It is the schematic which illustrated the structural formula of SWNT.

FIG. 2 (a) shows a bundle SWN composed of several hundred SWNTs.
FIG. 3 is a diagram illustrating an HRTEM image of T. (B) is a diagram illustrating an electron diffraction pattern of a bundle of SWNTs.
(C) illustrates a diagram obtained by performing a Fourier transform on the HRTEM image (a).

FIG. 3 (a) shows several bundles of (Gd ＠ C ₈₂ ) _n ＠SWNT
Of the spectrum obtained by electron energy loss spectroscopy
N (4d) absorption edge of d (up to 145 eV) and K of carbon
(1s) Absorption edge (up to 285 eV) is exemplified. (B)
Indicates the M (3d) absorption edge of Gd obtained from the same sample as (a).

Continued on the front page (72) Inventor Shunji Bando 5-1305 Akaike Nisshin, Aichi Prefecture Actopia Akaike II-201 (72) Inventor Kazuchi Suenaga 601 Amur Nakadaira 1-603 Nakadaira, Tenpaku-ku Nagoya City Aichi Prefecture (72) Inventor Kaori Hirahara 1-45 Umemoridai, Nisshin City, Aichi Prefecture Corp. Umego 203 (72) Inventor Toshiya Okazaki 1-31-1, Kamimuracho, Showa-ku, Nagoya-shi, Aichi U-House Dome Yotsuya 1004 (72) Inventor Shinohara Hisanori 3-917 Uedahonmachi, Tenpaku-ku, Nagoya-shi, Aichi F term (reference) 4G046 BC00 CB01 5G301 CD10

Claims (4)

[Claims] 1. A hybrid single-walled carbon nanotube comprising a single-walled carbon nanotube and a foreign substance encapsulated in a cavity in the cylinder. 2. The method according to claim 1, wherein the foreign substances included are carbon clusters,
The hybrid single-layer carbon according to claim 1, wherein the carbon is one or more of a metal, an organic molecule, an organometallic compound, a magnetic substance, a semiconductor, a superconductor, a complex, a gas, and an inorganic solid compound. Nanotubes. 3. The hybrid single-walled carbon nanotube according to claim 1, wherein the foreign substance included is a metal-encapsulated fullerene. 4. The hybrid single-walled carbon nanotube according to claim 1, wherein the contained foreign substance is a toxic gas.