WO2019039516A1

WO2019039516A1 - Carbyne-containing composite material

Info

Publication number: WO2019039516A1
Application number: PCT/JP2018/031025
Authority: WO
Inventors: 剛橋本; 橋本　悟; 弥八齋藤; 郷史當間
Original assignee: 株式会社名城ナノカーボン
Priority date: 2017-08-25
Filing date: 2018-08-22
Publication date: 2019-02-28
Also published as: JPWO2019039516A1; JP7168570B2

Abstract

Provided is a carbyne-containing composite material which is a carbon nanotube aggregate which contains carbyne therein at a higher filling rate. The provided carbyne-containing composite material contains carbyne and a CNT aggregate obtained by aggregating a plurality of carbon nanotubes. Carbyne is filled to at least 30% of the plurality of carbon nanotubes. The carbyne filling rate F is calculated, for example, on the basis of the subsequent formula from: the relative intensity ILCC/G * of the LCC band relative to the G band in carbon nanotubes filled with carbyne at a filling rate of 100%, and the relative intensity ILCC/G of the LCC band relative to the G band in a carbyne-containing composite material. F(%)=ILCC/G/ILCC/G*×100

Description

Calvin-containing composite material

The present invention relates to carbin-containing composites.
This application claims priority based on Japanese Patent Application No. 2017-162599 filed on Aug. 25, 2017, the entire contents of which are incorporated herein by reference.

Carbin (carbyne) is a carbon allotrope in which carbon atoms (C) are bonded in one dimension. Calvin was identified in 1885, but because it is unstable in the atmosphere, its identification was made in the 1960s. Then, last year, it was reported that by using double-walled carbon nanotubes (DWNT) as a nanoreactor, it is possible to stably generate very long calvin in the internal space of DWNT (see Non-Patent Document 1) ).

Non-Patent Document 1 discloses that Calvin can be suitably formed inside DWNT by heating DWNT at a high vacuum of 8 × 10 ⁻⁵ Pa and a high temperature of 1460 ° C. In addition, it is described that carbine can be grown only with DWNT having an inner tube diameter in the range of 0.62 to 0.85 nm, and 90% or more of DWNT of the inner diameter is filled with carbine. However, according to the author of Non-Patent Document 1, even if the preparation conditions of DWNT are optimized, DWNT having the above-mentioned tube diameter can be obtained to only about 25% of the prepared DWNT set. Absent. Also, it is reported that only 24% of DWNTs in the prepared DWNTs are filled with calvin.

The present invention has been made in view of the above-mentioned point, and its main object is to provide a carbyne-containing composite material which is an aggregate of carbene-containing carbon nanotubes with a higher filling rate.

The carbyne-containing composite material provided by the present invention includes a CNT aggregate in which a plurality of carbon nanotubes (carbon nanotubes: CNT, hereinafter may be simply referred to as “CNT”) are assembled, and carbine. And, the above-mentioned calvin is filled in 30% or more of the above-mentioned plurality of CNTs.

That is, the carbyne-containing composite material disclosed herein contains carbyne in CNT at a higher filling rate than heretofore known. It has been reported that, even when CNT has intrinsically semiconductive properties based on its crystal structure, it is possible to impart metallic properties to CNT by introducing carbin into the CNT. From this, for example, even if the CNT assembly contains a large amount of CNTs exhibiting semiconductive properties, by introducing calvin at a high filling rate, overall high metallic properties (for example, high electrical conductivity) Can be provided. Thus, the carbyne-containing composite material can realize a material in which the characteristics possessed by carbine are more strongly reflected as compared with conventional CNTs and CNTs containing carbine. The characteristics of the carbine provided in the carbyne-containing composite material may be various characteristics without being limited to the electrical conductivity.

In a preferred embodiment of the carbyne-containing composite material disclosed herein, the relative intensity of the peak based on LCC band is 0 when the intensity of the peak based on G band is 1 in the Raman spectrum measured by Raman spectroscopy. .4 or more. Such a configuration also realizes a carbin-containing composite material in which a large amount of carbin is introduced.

In a preferred embodiment of the carbyne-containing composite material disclosed herein, the carbon nanotube encapsulating the carbyne is at least partially represented as single-walled carbon nanotube (SWNT), hereinafter simply referred to as “SWNT”. There is a case. More preferably, the above-mentioned CNT containing the above-mentioned carbine contains 10 or more% of SWNTs. Non-Patent Document 1 discloses that SWNT has relatively low thermal stability as compared to DWNT and the like, and therefore it can not form carbin therein. However, in the carbyne-containing composite material disclosed herein, carbyne can be stably contained in SWNTs. In other words, the calvin-containing composite material disclosed herein can be a novel calvin-containing SWNT (calvin @ SWNT). Such a carbyne-containing composite material is preferable because it can more effectively increase the proportion of carbine in the entire composite material. This is also useful in that it can be a material in which the properties of SWNT and Calvin are strongly reflected.

The proportion of CNTs having a specific structure in the CNT assembly can be grasped, for example, by observation with a transmission electron microscope (TEM). Specifically, for example, the proportion of SWNTs in a CNT assembly can be obtained by calculating the proportion (several%) of the total number of SWNTs in the total number of CNTs observed in the field of view in TEM observation. it can. The number of CNTs may be measured, for example, for CNTs having a length of 500 nm or more, which can be confirmed in an observation image. As the number of CNTs, for example, a value measured based on an observation image at a magnification of about 50,000 to 500,000 can be preferably employed.

In a preferred embodiment of the carbyne-containing composite material disclosed herein, at least a portion of the CNTs encapsulates two or more carbins in a direction orthogonal to the axial direction of the CNTs. That is, CNT can contain two or more calvins arranged in the short direction. It is known that Calvin is formed intermittently along the longitudinal direction (axial direction) inside the CNT. That is, a plurality of calvins can be included in the CNT along the longitudinal direction. However, there has been no report on CNTs encapsulated in a state of bundling two carbins. The calvin-containing composite material disclosed herein can include such novel calvin-containing CNTs (calvin @ CNT).

As described above, the technology disclosed herein provides an unprecedented novel carbin-containing composite material. This carbin containing composite material can have the characteristics of the CNT assembly and the carbin together. For example, Calvin is theoretically reported to have twice the tensile strength with respect to graphene, and the stiffness is reported to be about twice as high as that of graphene and CNT and about three times that of diamond. Thus, for example, a carbyne-containing composite material can be of significantly improved tensile strength and stiffness relative to the CNT assembly.

On the other hand, as described above, Calvin may have the function of converting semiconducting CNTs into metallic properties. Thus, for example, a carbyne-containing composite material can be one that enhances the electrical conductivity of the CNT assembly. Thus, the carbyne-containing composites disclosed herein provide new materials that enhance or modify the properties of the CNT assembly. This novel material can be used in applications similar to conventional CNTs, or in new and unprecedented applications. From this, the technology disclosed herein can provide various articles including a carbine-containing composite material.

In still another aspect, the technology disclosed herein also provides a method of producing a carbine-containing composite material. In this manufacturing method, a plurality of carbon nanotubes are collected, and a carbon nanotube assembly having a G / D ratio of 25 or more is prepared, and a voltage at least at which electric field electron emission occurs is applied to the carbon nanotube assembly. ,including. This allows, for example, the above-mentioned carbyne-containing composite material to be manufactured under the relaxed conditions of temperature and lower degree of vacuum significantly lower than those disclosed in Non-Patent Document 1. Thereby, the said carbin containing composite material can be manufactured simply.

It is the figure which showed typically the crystal structure of the carbine included in SWNT contained in the carbine containing composite material which concerns on one Embodiment. It is a Raman spectrum of CNT which included 100% of calvin disclosed by the nonpatent literature 1. FIG. It is a Raman spectrum about the carbyne content composite material concerning one embodiment. It is an example of the Raman spectrum about the CNT sheet which does not contain calvin. It is a SEM image which shows the Raman-spectrum measurement position (a)-(c) of the carbine containing composite material which concerns on other embodiment. FIG. 5B is a Raman spectrum of the calvin-containing composite material at measurement positions (a) to (c) shown in FIG. 5A. (A) to (C) are TEM images of SWNT in a CNT sheet not containing calvin, (D) is a view showing the result of gradation profile analysis of (A). It is a TEM image of SWNT contained in the carbyne content composite material concerning one embodiment. It is a TEM image of other SWNTs contained in the carbyne content composite material concerning one embodiment. (A) (B) is a figure which shows the result of the gradation profile analysis of the area | region enclosed by the square of FIG. 7A and 7B, respectively. (A) and (B) are TEM images of DWNTs included in a carbin-containing composite material according to one embodiment. (A) (B) is a figure which shows the result of the gradation profile analysis of the area | region enclosed by the square of FIG. 9 (A) (B), respectively. (A) is a TEM image of MWNT contained in the carbyne content composite material concerning one embodiment, (B) is a figure showing the result of the gradation profile analysis of the field surrounded by the square. (A) is a TEM image of DWNT contained in the carbyne content composite material concerning one embodiment, (B) is a figure showing the result of the gradation profile analysis of the field surrounded by the square.

Hereinafter, preferred embodiments of the present invention will be described. In addition, matters other than matters particularly mentioned in the specification (for example, the constitution of a calvin-containing composite material) and matters necessary for the practice of the present invention (for example, a method for producing a CNT aggregate as a starting material) Can be understood as design matter of those skilled in the art based on prior art in the field. The present invention can be implemented based on the contents disclosed in the specification and the drawings and technical common knowledge in the field. In the present specification, the notation “X to Y” indicating a numerical range means “X or more and Y or less” unless otherwise specified.

[Carbin containing composite material]
The carbyne-containing composite material disclosed herein includes a CNT assembly in which a plurality of CNTs are assembled, and carbyne. And, calvin is filled (included) in CNT. Hereinafter, each component of a calvin containing composite material is demonstrated.

[CNT assembly]
The CNT assembly is a main component of the carbyne-containing composite material disclosed herein. And it has a role as a protective case which holds Calvin stably. In addition, the CNT assembly also has a function as a reactor of Calvin in the production of a Calvin-containing composite material described later. The configuration and the like of the CNT assembly are not particularly limited, and various CNT assemblies in which a plurality of CNTs are separately or integrally assembled can be considered. From the viewpoint of ease of handling, a plurality of CNTs may be integrated together. In addition, the CNT assembly may be constituted, for example, by a plurality of CNTs grown oriented in a direction perpendicular to the substrate. Here, the number of CNTs constituting the “CNT assembly” is not strictly limited, and one example is a large number (for example, about 10 or more, preferably about 50 or more, more preferably about 100 or more) of CNTs. It can be considered as one consisting of a set. However, it can be said that it is not realistic to define the CNT assembly by the number of CNTs constituting it. Although not necessarily limited to this, for example, in terms of facilitating industrial handling, for example, “CNT aggregate” may be grasped as a set of 1 μg or more of CNTs. The CNT assembly may be an assembly of 10 μg or more of CNTs, may be 100 μg or more, for example, 1000 μg or more. There is no limitation on the upper limit of the mass of CNTs constituting the CNT assembly.

The CNT assembly may be formed of SWNT in a form in which one graphene sheet is rolled in a cylindrical shape, or may be formed of DWNT in a form in which two different diameter SWNTs are nested. Alternatively, three or more different diameter SWNTs may be constituted by multi-walled carbon nanotubes (MWNT) in a nested form. In addition, the CNT assembly may be formed by mixing two or more of these SWNTs, DWNTs, and MWNTs. In the present specification, three or more layers of CNTs are collectively referred to as MWNT, and unless otherwise specified, the ratio etc. shall mean the value for the entire MWNT. As MWNT, for example, about 3 to 200 layers of CNTs are common, and typically about 3 to 60 layers of CNTs. In addition, CNTs can have different layer structures, such as one layer, two layers, and three layers in one tube. In such a case, the number of layers with the highest proportion in the CNT may be adopted as the number of layers of the CNT.

The CNT aggregate is not necessarily limited to this, but the ratio of SWNT to the total of SWNT, DWNT and MWNT is preferably 10% or more (10% or more based on the number). It is preferable to increase the amount of carbin contained per unit weight of the CNT assembly by increasing the proportion of SWNTs constituting the CNT assembly. The percentage of SWNTs in the CNT aggregate is more preferably 20 numbers% or more, still more preferably 30 numbers% or more, particularly preferably 40 numbers% or more, for example, 50 numbers% or more. The ratio of SWNTs may be 60 lines% or more, 70 lines% or more, 80 lines% or more, 90 lines% or more, and substantially 100 lines%. It may be.

In recent years, the method of synthesizing SWNT has been greatly improved, and a method of synthesizing SWNT of higher quality in terms of purity and degree of graphitization has been proposed. In addition, in a CNT assembly including such SWNTs, the content ratio of SWNTs may be evaluated on a mass basis. Therefore, for example, the CNT aggregate is not necessarily limited to this, but the ratio of SWNT in the total of SWNT, DWNT and MWNT is preferably 30% by mass or more, and 40% by mass or more is more Preferably, it is 50% by mass or more, more preferably 60% by mass or more, and for example, 70% by mass or more. Also by this, for example, the mass ratio of CNTs occupying in the entire of the carbyne-containing composite material can be effectively reduced. The upper limit of the proportion of SWNT is not particularly limited, and may be, for example, substantially 100% by mass (for example, 95% by mass or less).

On the other hand, it is known that DWNT can easily form Calvin therein. From this point of view, in the CNT assembly, the ratio of DWNT in the total of SWNT, DWNT and MWNT may be 10% by mass or more, 15% by mass or more, for example, 20% by mass or more. It is also good. However, in the carbin-containing composite material disclosed herein, it is not necessary to increase the proportion of DWNT in order to convolute the calvin in the CNT at a high proportion. From this point of view, the CNT assembly is not necessarily limited to this, but for example, the proportion of DWNT in the total of SWNT, DWNT and MWNT may be 70% by mass or less, 60% by mass or more For example, 50 mass% or less may be sufficient. In addition, 30 mass% or less is preferable, for example, 20 mass% or less is more preferable, for example, 10 mass% or less may be sufficient as the ratio of MWNT to the sum total of CNT.

Also, the average diameter of the CNTs in the CNT aggregate is not strictly limited, and may be, for example, 0.43 nm or more and 100 nm or less, and typically 0.5 nm or more and 50 nm or less, preferably 0.6 nm. The thickness is 10 nm or less. The diameter of the CNT aggregate means a tube diameter (diameter) for SWNT and a tube system (diameter) for the innermost CNT for two or more CNT layers. In the carbyne-containing composite material disclosed herein, although not necessarily limited thereto, it is confirmed that carbyne can be suitably contained in CNTs having a diameter of 0.6 nm or more, for example, 0.7 nm or more. ing. Therefore, the average inner diameter of the CNTs in the CNT aggregate is preferably 0.6 nm or more, more preferably 0.7 nm or more, and can be, for example, 0.8 nm or more. For CNTs containing carbin, for example, the average inside diameter of the CNTs is preferably 5 nm or less, more preferably 2 nm or less, from the viewpoint that carbin can be present more stably.

It is appropriate that the average length of the CNTs is typically 1 μm or more. From the viewpoint of lowering the resistance and increasing the film strength, the average length of the CNTs is preferably 3 μm or more, more preferably 5 μm or more, still more preferably 8 μm or more, particularly preferably 10 μm or more, for example, 10 μm or more. The upper limit of the average length of the CNTs is not particularly limited, but is preferably about 30 μm or less, and may be, for example, 25 μm or less, typically 20 μm or less, for example 15 μm or less. For example, a CNT having an average length of 5 μm to 30 μm, preferably 10 μm to 25 μm, and typically 12 μm to 20 μm is suitable.

The average value of the aspect ratio of CNT (CNT length / diameter) in the CNT assembly is not particularly limited, but is typically 100 or more. The larger the aspect ratio of the CNTs, the easier it is for the CNTs to be mechanically entangled with each other and to form an integral assembly. Furthermore, it is preferable also in the point which can form the aggregate | assembly of a desired shape, without including a binder. The average aspect ratio of the CNTs is preferably 250 or more, more preferably 500 or more, still more preferably 800 or more, particularly preferably 1000 or more, from the viewpoint of, for example, enhancing the low resistance properties and strength of the CNT assembly. The upper limit of the average aspect ratio of the CNTs is not particularly limited, but from the viewpoint of handleability, easiness of production, etc., approximately 25000 or less is suitable, preferably 20000 or less, more preferably 15000 or less, still more preferably It is 12000 or less, particularly preferably 10000 or less. For example, CNTs having an average aspect ratio of 100 to 10000 are preferable. In addition, the average aspect ratio (CNT length / diameter), average length, and average diameter of CNT can employ | adopt the value typically acquired by the measurement based on an electron microscope observation.

Calvin
In the carbyne-containing composite material disclosed herein, carbyne is contained in CNT, as shown in FIG. 1, for example. Calvin and CNT have the same longitudinal direction (axial direction). As described above, carbin is one of allotropes of carbon, and has a structure in which carbon atoms are linearly and sp-bonded in one dimension. Specifically, as shown in the following formulas (1) and (2), carbyne has a polyyne structure (1) in which adjacent carbon atoms are alternately bonded by a triple bond and a single bond, and a continuous double It can be represented by the resonance structure of the bonded cumulene structure (2). Therefore, Calvin has a thickness (diameter) of one carbon atom, and the length is sufficiently long with respect to this thickness (for example, about 9 nm or more), so Calvin is an ultimate one-dimensional substance. .

-C≡C-C≡C-C≡C-C-C≡C-C≡C- ... (1)

= C = C = C = C = C = C = C = C = C = C = C = C = (2)

In Non-Patent Document 2, precise simulation using a computer is performed on Calvin represented by the formulas (1) and (2) to predict that Calvin is harder than any substance existing in the world. Specifically, the tensile strength is about twice that of graphene, and the stiffness is about twice that of graphene and nanotubes, and about three times that of diamond. In addition, Calvin turns into a magnetic semiconductor when it is twisted by 90 ° with its coupling direction as the axis of rotation, and it is expected that energy will be stored and it will be stable even at room temperature. The phase diagram of Calvin is said to exist in a narrow region surrounded by gas phase, liquid phase, diamond and graphite, but since actual Calvin is a very unstable substance under normal pressure, The details are not disclosed.

However, even such carvin can be stably present at normal temperature and pressure by being contained in CNT. The Calvin-containing composite material disclosed herein contains a Calvin, in the Raman spectrum obtained by Raman spectroscopic analysis, approximately from 1850 cm ^-1 in the range of 1865cm ^-1, a linear carbon chain (linear carbon chains: LCC The presence of calvin can be confirmed by the fact that a band-based peak is observed. In other words, detection of the LCC band makes it possible to confirm that calvin is contained in the CNT.

In the present specification, unless otherwise specified, a Raman spectrum means a spectrum obtained by Raman spectroscopy using a laser with a wavelength of 532 nm as excitation light. In addition, in the Raman spectrum of such a carbyne-containing composite material, a peak based on a G band is observed around 1590 cm ⁻¹ derived from the graphite structure of CNT. In addition, in the Raman spectrum of such a carbyne-containing composite material, a peak based on D band can be observed around 1350 cm ⁻¹ due to the defect of the graphite structure.

In addition, the carbin containing composite material indicated here contains carbin in CNT in many ratios rather than before. As a result, in the Raman spectrum, the relative intensity I _{LCC of the} peak based on the LCC band, ie, the relative intensity I _LCC / I _G , is 0, where the intensity I _G of the peak based on the G band is “1” (reference). .4 or higher. The relative intensity _I LCC / _{I G} is preferably 0.8 or more, more preferably 1.0 or more, more preferably 1.2 or more, particularly preferably 1.5 or more. The relative intensity _I LCC / _{I G} can be 2 or more, more preferably 2.5 or more, 3.0 or more is particularly preferable. The upper limit of the relative intensity I _LCC / I _G is not strictly limited. For example, as described below, since the relative intensity _I LCC / _{I G} for Calvin encapsulated portion of CNT disclosed in Non-Patent Document 1 (local) it is 6.1, the upper limit of the relative intensity _I LCC / _{I G} Can be about 6.1.

In the carbin-containing composite material disclosed herein, the amount of carbin contained in the CNTs can also be evaluated by the filling rate of carbin. In the carbin containing composite material disclosed herein, the filling rate of carbin is preferably 30% or more. CNT assemblies containing carbin at such high filling rates have not been known so far. The filling rate of carbin can be further increased by adjusting the method for producing a carbin-containing composite material described later and the starting material. For example, the filling rate of calvin may be 32% or more, more preferably 33% or more, particularly preferably 35% or more, and still more preferably 37% or more, for example, 40% or more.

In the present specification, the filling rate of carbin to CNTs is defined as follows. That is, first, the filling ratio of the carbin is defined as 100% with respect to the calvin-containing portion of one CNT which contains one long carbin without intermittent in the length direction. Then, in the Raman spectrum of the 100% packing ratio of the calvin, when the peak intensity I _{G *} based on G band is “1”, the peak intensity I _{LCC *} based on LCC band, ie, I _{LCC *} / The relative intensity I _{LCC / G *} (reference) of the LCC band to the G band at 100% filling rate is defined as I _{G *} . Further, in the Raman spectrum of the Calvin-containing composite material, the intensity I _G of the peak based on the G bands when a "1", the intensity I _LCC of peaks based on LCC band, LCC band for G bands of Calvin-containing composite material Relative strength I _{LCC / G.} At this time, the Calvin filling factor F of CNT in the Calvin containing composite material is represented by the following formula.
F (%) = I _{LCC / G} / I _{LCC / G *} x 100

The relative intensity I _{LCC / G *} of the LCC band to the G band when the filling rate is 100% may adopt a value obtained by measurement using a calvin-containing CNT having a filling rate of 100%, for example, non You may use "6.1" which is a value calculated based on the Raman spectrum disclosed by patent document 1. FIG. The Raman spectrum disclosed in Non-Patent Document 1 is shown in FIG.

In addition, the less the surface defects in the CNT aggregate portion, the more the carbin-containing composite material is, because the intermolecular force between the respective CNTs is effectively enhanced. In addition, in the case where the CNTs exhibit metallic properties, the conductivity may increase as the surface defects decrease. Therefore, it is preferable that the CNT assembly has less surface defects. In this respect, the calbin-containing composite material disclosed herein has a ratio ( _IG / _ID : G / D ratio) of peak intensity I _G based on G band to intensity I _D of peak based on D band. High is preferred. The G / D ratio of the carbin-containing composite material is, for example, preferably 6 or more, more preferably 7 or more, still more preferably 8 or more, and particularly preferably 10 or more.

[Use]
In the above-described carbin-containing composite material, carbin is contained at a higher rate than ever in the CNT assembly. Thus, in addition to the intrinsic properties of CNTs, the calvin-containing composite material can also possess properties derived from calvin. For example, an article can be provided that has high strength as compared to conventional CNT sheets and the like. On the other hand, calvin can cause changes in the properties of CNTs containing calvin. For example, although SWNTs differ in whether they exhibit metallic properties or semiconducting properties depending on chirality, they are practical because DWNT and MWNT exhibit metallic properties as a whole by including even more metallic properties of CNTs. It is known that almost all DWNTs and MWNTs can exhibit metallic properties. Since the carbyne-containing composite material disclosed herein can suitably contain SWNT, when the SWNT exhibits semiconductive properties, the carbyne-containing composite material can be modified to exhibit metallic properties by being made into a carbyne-containing composite material. . By this, for example, it is possible to make the properties of the CNT in the CNT aggregate in which the formation of the metal / semiconductor is not complete is uniform to the metallic property. An article comprising such a carbyne-containing composite material can be used in place of almost all conventional CNT-based products. For example, an article comprising a carbyne-containing composite material may be particularly useful as a lightweight material for mechanical or conductive material applications, and the like. As a suitable example of such an article, for example, a transparent electrode, a transparent conductive film and the like can be mentioned.

[Method for producing carbin-containing composite material]
Also, according to the technology disclosed herein, a suitable method for producing the above-mentioned carbine-containing composite material is provided. This manufacturing method includes the following steps (1) to (2). Each step will be described below.
(1) A plurality of CNTs are assembled as a starting material, and a CNT assembly having a G / D ratio of 25 or more is prepared.
(2) A voltage at which at least Field Electron Emission (FE) occurs is applied to the CNT assembly.

[1. Preparation of starting material]
The carbin containing composite material uses CNT aggregates as a starting material. The CNT aggregate may be prepared to have substantially the same configuration as the intended carbin-containing composite material. For example, SWNT, DWNT, and MWNT proportions, shapes, and aggregation forms in the CNT assembly of a carbin-containing composite material may provide a CNT assembly having a desired aspect at the stage of the starting material. From the viewpoint of facilitating the generation of FE in the next step, it is preferable to use a sheet-like CNT aggregate having a substantially flat surface shape. The CNT assembly may be held by any base material, or may be prepared as an independent body of only the CNT assembly.

As the above-mentioned CNT assembly, from the viewpoint of suitably generating FE, one having a G / D ratio of 25 or more measured by Raman spectroscopic analysis can be preferably employed. It can be evaluated that the larger the G / D ratio is, the smaller the number of surface defects of the CNT and the higher the crystallinity. This makes it possible to generate FE in a suitable state in the next step. In addition, since the number of surface defects of the CNTs is small, the intermolecular force between the CNTs is effectively enhanced. Therefore, in formation of a CNT aggregate, it is suitable also in the point which can realize high film intensity, for example, without requiring a binder. The G / D ratio of CNTs is preferably 28 or more, more preferably 30 or more, and particularly preferably 35 or more. For example, the G / D ratio of CNT may be 50 or more, and typically 100 or more. The upper limit of the G / D ratio of the CNT is not particularly limited, but may be, for example, 200 or less, typically 150 or less, for example 120 or less, from the viewpoint of ease of production and the like. The method for producing this CNT assembly is not particularly limited. For example, it may be a CNT aggregate manufactured by an arc discharge method, a CVD method or the like. However, a CNT assembly having a high G / D ratio as described above is preferably produced, for example, by the CVD method.

Also, the purity of the CNT assembly is not particularly limited, but typically 85% or more. The purity as used herein is the ratio of the carbonaceous material (CNT and amorphous carbon) in the CNT aggregate. The purity of the CNT aggregate is preferably 90% or more, more preferably 95% or more, from the viewpoints of suppression of variation in FE, reduction in resistance, improvement in film strength, and the like. The upper limit of the purity of the CNT assembly is not particularly limited, and may be typically 99% or less, for example, 98% or less from the viewpoint of ease of production and the like. The technology disclosed herein can be preferably practiced, for example, in a mode in which the purity of the CNT assembly is 85% or more and 100% or less (typically, 95% or more and 99% or less). In the present specification, as the purity of CNT, a value obtained by measurement with a differential thermal gravimetric analysis (TG-DTA) apparatus can be adopted. For example, as an example, in the TG / DTA chart, the content of CNT, which is the sum of SWNT and amorphous carbon, is calculated from the weight loss ratio due to combustion of SWNT at around 683 ° C and combustion of amorphous carbon at around 322 ° C. Can. When the CNT assembly contains DWNT or MWNT, the weight loss associated with their combustion may be taken into consideration.

Furthermore, the bulk density of the CNT assembly is not particularly limited. For the purpose of obtaining a carbyne-containing composite material containing a higher concentration of carbine, for example, the bulk density of the CNT assembly is preferably 0.1 g / cm ³ or more, and 0.3 g / cm ³ or more. More preferably, 0.5 g / cm ³ or more is particularly preferable. The upper limit of the bulk density of the CNT aggregate is not particularly limited. For example, an excessively dense CNT aggregate may increase the proportion of CNTs composed of MWNTs or increase the proportion of CNTs broken due to consolidation. The bulk density of the CNT aggregate can be typically 1 g / cm ³ or less from the viewpoint of easily avoiding such inconvenience. The bulk density is more preferably a value for CNTs that do not contain a catalyst metal, an amorphous metal, etc. described later.

Furthermore, the CNT assembly can be allowed to contain, for example, a catalyst metal used for synthesis of CNT and the like. The catalyst metal may be, for example, at least one metal selected from the group consisting of Fe, Co and platinum group elements (Ru, Rh, Pd, Os, Ir, Pt) or an alloy containing such a metal. Such catalytic metals can be included in the CNT aggregate typically in the form of fine particles (eg, about 3 nm to 100 nm in average particle size). In a preferred embodiment of the CNT assembly as a starting material, 85 atom% or more (more preferably 90 atom% or more) of the carbonaceous material is a carbon atom (C). 95 atomic% or more of the carbonaceous material may be a carbon atom, 99 atomic% or more may be a carbon atom, or a CNT substantially consisting of only carbon atoms may be used. A product obtained by any post-treatment (for example, purification treatment such as removal of amorphous carbon, removal of catalyst metal, etc.) may be used as the above-mentioned CNT.

In addition, the CNT aggregate may contain materials other than the above-mentioned carbonaceous material and catalyst metal (hereinafter, also referred to as an additive material) within a range not significantly preventing the occurrence of FE in the next step. Examples of such additive materials include resin binders, conductive materials, thickeners and the like. However, the content of these additive materials is, for example, 10% by mass or less, preferably 7% by mass or less, more preferably 5% by mass or less, based on the total mass of the CNT aggregate. Is 3% by mass or less. Among them, a preferred embodiment is that the CNT assembly is substantially free of a resin binder having an insulating function.

[2. FE processing of CNT aggregate]
The carbyne-containing composite material disclosed herein can be obtained by applying a voltage to the above-prepared CNT assembly to generate or equalize FE. The voltage to be applied, the atmosphere conditions, and the like can not be generally mentioned because they differ depending on the properties (crystallinity and shape, and in turn, field emission characteristics) of the CNT assembly. The fact that the CNT assembly emits electrons by the action of the electric field can be confirmed, for example, by the flow of a weak current (FE current) between the applied electrodes by the application of the electric field to the CNT assembly. In general, field emission for metallic materials can not be stably generated unless under an ultra-high vacuum atmosphere (typically, an atmosphere of 10 ^-8 Pa or less). However, by using a CNT assembly having the above-mentioned high crystallinity as a starting material, it is possible to generate FE at a looser reduced pressure environment and / or at a lower voltage than before. And by creating an FE environment in a CNT assembly having such high crystallinity, it is considered that an environment more suitable for the formation of calvin is prepared.

Such a reduced pressure environment can be, for example, a pressure exceeding 10 ^-5 Pa (eg, 10 ^-5 Pa or more and about 10 Pa or less). JIS Z8126-1: According to ^1999, the following vacuum ¹⁰ -5 Pa since it is defined as "ultra high vacuum", according to the art disclosed herein, a reduced pressure environment for the FE, for example 10 ^- The “high vacuum” exceeding ⁵ Pa and 0.1 Pa ⁻¹ or less or the “medium vacuum” exceeding 0.1 Pa ^{−1 and} 10 Pa or less can be used. A more in terms of the generating the FE in an environment close to the atmospheric pressure, reduced pressure environment is preferably at least ¹⁰ -4 ^Pa, more preferably at least ¹⁰ -3 ^Pa, particularly preferably at least ¹⁰ -2 Pa, 10 ^{- 1} Pa or more is more preferable, for example, it is good also as 10 ⁰ Pa or more.

In addition, voltage conditions for generating an electric field largely depend on the crystallinity and surface morphology of the CNT assembly, the distance between electrodes, etc. For example, in the case where the distance between electrodes is 1.6 mm, as a rough guide, it is preferable to exceed 0 V, for example, about 0.5 kV or more, and more preferably about 1 kV or more. The voltage condition for generating the electric field may be, for example, about 3 kV or less, more preferably about 2.8 kV or less, for example, about 2.5 kV or less. There is no strict restriction on the direction of the electric field. However, it is preferable to apply an electric field in the direction intersecting with the tube axis of CNT from the viewpoint of more suitably exposing the CNT to a state in which FE can be generated. Thus, it is considered that energy from a high electric field can be suitably supplied to the CNT assembly, and such energy can be used for formation of carbin without excessive loss by FE. For example, when the CNT assembly is sheet-like, the direction of the electric field is preferably a direction intersecting the surface rather than a direction parallel to the surface, and approaches the direction perpendicular to the surface. Is more preferable. Thereby, an electric field can be effectively applied to the entire CNT assembly.

Although the details are not clear, the action of the electric field allows electrons in the CNT to move smoothly and at low resistance through the tube wall (graphene sheet). And in the part of the CNT assembly where the electric field is concentrated, the electron extracting action is expressed. It is considered that this causes disorder in bonding of carbon atoms constituting the CNT at the site, and carbon atoms are arranged in a one-dimensional manner at the center of the inner space of the CNT to form carbine by sp bonding. Alternatively, volatilization of the amorphous carbon contained in the CNT aggregate is considered to similarly form carbine in the center of the inner space of the CNT. A discharge phenomenon (insulation breakdown) is not necessary at the time of field emission. In other words, an electric field may be applied by a nondestructive voltage. However, for the formation of calvin, it is preferable to apply a relatively high voltage to the CNT assembly. From this point of view, it is acceptable to generate a discharge upon field emission in order to contain more carbine in the carbine-containing composite material. In this case, with discharge, the G / D ratio of CNTs in the carbyne-containing composite material may decrease as described above. Thus, in the vicinity of the field emission of the CNT assembly, carbine may be formed inside the CNT. Carbin is filled in the CNT at a relatively high rate of, for example, a filling rate of 30% or more. This makes it possible to produce the carbyne-containing composite disclosed herein.

EXAMPLES Specific examples of the present invention will be described below, but the present invention is not intended to be limited to those shown in the specific examples.

[Test Example 1]
Three sheet-like CNT aggregates having different G / D ratios (hereinafter, simply referred to as "CNT sheet") were prepared. Specifically, the CNT sheet of Example 1 is a sheet made of SWNT "EC 1.5" manufactured by Meijo Nano Carbon Co., Ltd. The EC 1.5 is mainly composed of SWNTs produced by the CVD method. The CNT sheet of Example 2 is a sheet mainly made of SWNT manufactured by the arc discharge method manufactured by Meijo Nano Carbon Co., Ltd. The CNT sheet of Example 3 is a "high purity CNT tape" manufactured by JFE Engineering Corporation. The CNT sheet of Example 3 is a sheet made of MWNT produced by an arc discharge method. Each of these CNT sheets is a CNT-shaped bucky paper molded into a sheet, and no binder is contained in any of the sheets.

Raman spectroscopic analysis was performed on the prepared CNT sheets of Examples 1 to 3, and the G / D ratio was calculated from the obtained Raman spectrum and is shown in Table 1. For Raman spectroscopy, a laser with a wavelength of 532 nm was used as excitation light, using a microscopic Raman spectrometer (inVia Reflex, manufactured by Renishaw). Further, the bulk density of the CNT sheet of each example, the average diameter of the CNTs constituting the sheet, and the thickness of the sheet were measured and shown together. In addition, the average diameter of CNT is an arithmetic mean value of the diameter of 10 points | pieces of CNT measured by observation using a scanning electron microscope (Scanning Electron Microscope: SEM) and TEM. In the measurement of the diameter, SWNT was a measurement target in the sheets of Examples 1 and 2, and an arbitrary MWNT was a measurement target in the sheet of Example 3. Moreover, sheet | seat thickness is an arithmetic mean value of the thickness of three or more points of each CNT sheet | seat measured by cross-sectional observation using SEM.

[Carbin formation 1]
Next, the CNTs of the CNT sheets of Examples 1 to 3 prepared above were cut into squares of 5 mm square and used as measurement samples. Then, the samples of Examples 1 to 3 were placed in a vacuum chamber, and application of an electric field caused field electron emission (FE). Specifically, first, the samples of Examples 1 to 3 were fixed to an aluminum holder with silver paste to construct a cathode unit, and the cathode unit was mounted on a grounded stainless steel stage in a chamber. Further, the anode was made to face in parallel with the aluminum holder in the chamber, and a voltage was applied between both electrodes. That is, an electric field was applied in the direction perpendicular to the CNT sheet. The applied voltage was varied between 0 and 2.5 kV until discharge occurred. The pressure in the chamber was set to (a) approximately 1 × 10 ⁻⁵ Pa and (b) approximately 1 × 10 ⁻¹ Pa. Further, an insulating ceramic glass was inserted as a spacer between the electrodes, and the distance between the electrodes was adjusted to about 1.6 mm.

[Raman spectroscopy]
The Raman spectroscopy analysis was performed about the sample of each example after FE similarly to the above. In addition, the Raman spectrum was measured about the location which discharge generate | occur | produced among the samples of each case, or its vicinity. The G / D ratio was calculated from the obtained Raman spectrum and is shown in Table 2 below. Table 2 also shows the initial G / D ratio before FE together for reference. In addition, when a peak attributed to the LCC band was observed in the vicinity of 1860 cm ^-1 , the peak relative intensity (LCC / G ratio) of the LCC band to the peak intensity of the G band was calculated and listed in Table 2. Also, based on this LCC / G ratio, the filling rate of Calvin was calculated and listed in Table 2. However, for the sample of Example 3, the Raman spectroscopic analysis was omitted because the FE current itself was not observed when the pressure inside the chamber was set to a pressure close to about 1 × 10 ⁻¹ Pa. As a result of Raman analysis, the Raman spectrum of the obtained sample of Example 1 is shown in FIG. 3, and the Raman spectra of the samples of Example 2 and Example 3 are shown in FIG. Each Raman spectrum is shown by adjusting the peak intensity of the vertical axis so that the peak intensity of the G band is 1.

[Evaluation]
As shown in Table 1, D-band and G-band specific to CNT are observed in the Raman spectrum of the initial CNT sheet, and their G / D ratios are arranged in descending order in Example 1, Example 2, and Example 3 It has been confirmed that there is. From this, it was confirmed that the crystallinity of the CNTs constituting the CNT sheet was higher in the order of Example 1, Example 2, and Example 3.
Further, as shown in Table 2, it was found that the G / D ratio of the CNT sheet of Examples 1 and 2 was greatly reduced by the discharge accompanying FE. Since the D band is caused by a special vibration around defects of the crystal structure of the CNT, it was found that the CNT sheet of Examples 1 and 2 had the defect introduced into the CNT by the discharge. On the other hand, in the CNT sheet of Example 3 in which the crystallinity was originally relatively low, the G / D ratio increased as a result of the discharge, but the G / D ratio itself is a value close to 1 and a remarkable crystal It can be said that no change in sex is seen.

Then, for the CNT sheet of Example 1 having the highest G / D ratio, a peak based on the LCC band appears in the Raman spectrum by discharging with FE, and a peak based on the LCC band does not appear for the other CNT sheets. That was confirmed. This indicates that carbin was formed in the SWNTs of Example 1. For the CNT sheet of Example 1, the LCC band appeared even when the pressure in the chamber was (a) a high vacuum of about 1 × 10 ^-5 Pa and (b) a low vacuum of about 1 × 10 ^-1 Pa. As shown in FIG. 3, the peak height (LCC / G ratio) of the LCC band to the peak of the G band resulted in (b) being higher in the sample subjected to the FE discharge at a low vacuum. So far, it has been said that Calvin can be produced by heating DWNT to a high temperature under high vacuum of 10 ^-5 Pa to 10 ^-6 Pa order. However, in this test example, it was confirmed that calbin was produced even at about normal pressure of about 1 × 10 ⁻¹ Pa. Also, it has been said that, until now, calvin can not be produced without maintaining stability within MWNTs of two or more layers. However, in the present embodiment, it has been confirmed that calbin is also generated in the SWNT.

[Test Example 2]
[Carbin formation 2]
With respect to the CNT sheet of Example 1 prepared above, (a) applying a voltage to generate FE in the same manner as in Test Example 1 under a vacuum condition of about 1 × 10 ⁻⁵ Pa, to generate FE before discharge occurs. By finishing, an FE-CNT sheet without discharge was prepared. Then, among the prepared FE-CNT sheets, a Raman spectrum was obtained by Raman spectroscopy under the same conditions as above for three points at measurement positions a to c shown in FIG. 5A. The measurement positions a to c are all located at the end of the measurement sample at a portion where the CNT sheet is partially turned up. In the measurement sample of this test example, although discharge did not occur, impurities (for example, amorphous carbon) heated by the supply of high electric field energy are melted and vaporized, and part of the surface of the sheet is curled up by the generated vapor and the like. It is thought that The measurement position a is an area which is relatively uniform among them and has a flat surface morphology. Measurement positions b and c are raised up like a mountain ridge or a wall, and c looks brighter than b in the SEM image, so c is considered to be located higher from the sheet surface Be The obtained Raman spectrum is shown in FIG. 5B. The Raman spectrum at each measurement position is shown by adjusting the peak intensity on the vertical axis so that the peak intensity of the G band is 1.

As shown in FIG. 5B, it was found that a peak based on the LCC band was observed in all of the three Raman-analyzed sites, even for the CNT sheet that had been subjected to FE but not discharged. In other words, it was found that the formation of calvin was not necessarily triggered by the discharge. However, the value of the LCC / D ratio was significantly lower than that of Test Example 1 and the variation was also large. In this test example, the LCC / D ratio was in the range of 0.47 to 1.2. That is, it was found that although the formation of calvin does not necessarily require discharge, a situation is created in which calvin is likely to be formed along with the discharge. Since the LCC / D ratio increases in the order of the measurement positions a, b, and c, it is said that the position where the fluctuation of the CNT sheet due to the supply of the high electric field energy is large causes the formation of carbin. The three Raman spectra have no noticeable difference other than the peak height based on the LCC band, for example, the G / D ratio does not change significantly. From this, it is expected that not only the destruction (increase in defects) of the CNTs associated with the discharge does not necessarily affect the formation of calvin. In other words, Calvin is not formed using only carbon atoms of the defect portion (decay portion) of CNT as a carbon source, and it is expected that there is a portion due to the influence of high electric field energy.

[Reference example]
[Starting material]
The CNT sheet of Example 1 used in Test Example 1 was observed by TEM (manufactured by PHILIPS, CM120). The acceleration voltage of TEM was 80 kV. The TEM images obtained as a result are shown in FIGS. 6 (A) to (C). Further, with regard to the CNT shown in FIG. 6A, line scanning is performed in a direction orthogonal to the CNT in the region surrounded by a square in the figure, and the gray scale (contrast) of the TEM image is digitized to obtain a gray scale. We performed line scan analysis to process into a profile. The results are shown in FIG. 6 (D).

As a result, the CNTs shown in FIG. 6A were SWNTs composed of one layer of CNTs. The CNT shown in (B) was DWNT in which two different diameter SWNTs were nested. The CNT shown in (C) was a three-layer MWNT in which three different diameter SWNTs were nested. As shown in FIGS. 6 (A) to 6 (C), the CNT sheet of Example 1 is mainly (A) mainly composed of SWNTs (approximately 70 several% or more), and partially (B) DWNT or (C) It was confirmed to contain 3 layers of MWNT.

In the line scan result of FIG. 6D, the vertical axis corresponds to the contrast of the TEM image. The vertical axis means that the higher the position, the brighter the corresponding position of the TEM image, and the lower the value, the darker the corresponding position of the TEM image. As shown in FIG. 6 (D), this line scan makes the dark position corresponding to the SWNT wall shown by the arrow in FIG. 6 (A) into a deep valley, and other bright areas where nothing is observed. It can be confirmed that it appears in a mountain shape (hill shape). It has been confirmed that the gradation profile is substantially flat between the SWNT walls. In the gradation profile of the contrast of the TEM image of SWNT, for example, the difference ΔC between the gradation of a portion corresponding to the wall of SWNT (tube wall) and the brightest gradation among hollow portions sandwiched by the wall. The ratio (ΔC _H / ΔC) of the maximum variation ΔC _H of the gradation of the hollow portion to that of, in other words, the ratio of the contrast change of the hollow portion to the TEM contrast difference of the whole SWNT was about 0.15. As a tone difference ΔC between the wall portion and the hollow portion, a line connecting a pair of darkest contrast points (a1 and b1 in FIG. 6D) corresponding to the innermost wall is used as a baseline. The maximum contrast ΔC, which is an area between the pair of points (a1, b1) and in which the distance of the gray scale profile from the base line is maximum, is adopted. In addition, as the maximum variation ΔC _H of the gradation of the hollow portion, the maximum contrast at which the distance of the gradation profile from the base line is maximum in the region between the pair of points (a1, b1) The difference between the gray scale and the minimum contrast at which the distance of the gray scale profile is minimized was adopted. In the case of FIG. 6D, a set of points (a1, b1) corresponding to the wall is a point at which the scan point is about 1.1 nm and about 3.8 nm. The gray scale profile with the longest distance from the baseline connecting these points is the point where the scan point is about 1.6 nm and about 3.3 nm (the maximum contrast ΔC is about 8.6 scale each), and the distance is nearest tone profile, scan point is a point of about 2.75 nm (minimum contrast of about 7.3 scale), these differences [Delta] C _H was about 1.3 scale. From these pieces of information, the ratio (ΔC _H / ΔC) is calculated. In the contrast of the TEM image of CNT, the boundary between the relatively dark portion corresponding to the tube wall and the relatively bright portion corresponding to the hollow portion is not necessarily clear. Therefore, the peak of the bright part between the set of points (a1, b1) corresponding to the innermost tube wall and closest to the set of points (see FIG. 6D, the scan point is The region between maximum points of about 1.6 nm and about 3.3 nm) is conveniently determined to be the portion corresponding to the hollow portion of the CNT, and the gradation profile closest to the baseline is one set of these Measured between the maxima of

[Test Example 3]
[Carbin formation 3, Calvin containing composites: SWNT]
Then, after causing a plasma generated by a high frequency voltage to act on the CNT sheet of Example 1, under the vacuum condition of about 1 × 10 ^-5 Pa, a voltage is applied similarly to the above-mentioned Test example 1 to perform FE discharge. It was generated. More specifically, after applying a mask having a predetermined opening to the CNT sheet, plasma was applied to the CNT sheet in the vicinity of the opening of the mask by performing reactive ion etching (RIE). The conditions of the RIE are activating a reactive gas by applying a high frequency electric field of 200 W to a reactive gas consisting of oxygen (O ₂ ) and argon (Ar) in a reduced pressure atmosphere of 100 Pa, and radical ions generated thereby The surface of the CNT sheet was etched using the particles as etching particles. According to the above RIE conditions, all the CNT sheets in the mask opening disappear by etching, and reactive plasma can be applied to the CNT sheet in the vicinity of the opening of the mask. Then, with respect to the CNT sheet after RIE, the same FE discharge as in Test Example 1 was caused.

TEM observation was performed on SWNTs in the CNT sheet after RIE and FE discharge, and the results are shown in FIGS. 7A and 7B. Further, line scan analysis was performed in the direction orthogonal to the SWNT in the regions shown by squares in FIGS. 7A and 7B, and the results are shown in FIGS. 8A and 8B.

When the SWNT in FIG. 7A was observed, a faint contrast was observed at the center of the tube wall indicated by arrows a1 and b1, but extending slightly along the tube axis. Looking at the gray scale profile of FIG. 8A, it can be confirmed that one valley is formed in the middle of the positions a1 and b1 corresponding to the pair of tube walls. From the gray scale profile, it was confirmed that the diameter of the SWNT was about 1.9 nm, and the valley in the middle was located approximately at the center (axis) of the SWNT. Further, in the SWNT in FIG. 7B, a dark contrast was intermittently confirmed along the axis at the center of the pair of tube walls indicated by arrows a2 and b2. And also in the gradation profile of FIG. 8 (B), it has been confirmed that one valley is formed in the middle of the positions a2 and b2 corresponding to the tube wall. From the gray scale profile, it was confirmed that the diameter of the SWNT was about 1.4 nm, and the valley in the middle was located approximately at the center (axis) of the SWNT. From the contrast of TEM, what exists at the center of SWNT is a substance consisting of light elements. Also the contrast is much thinner than the tube wall of SWNT. From the above results, it can be concluded that a linear carbon allotrope, carbin, is formed at the center of SWNT. Calvin has been said to be stably formed only in two or more MWNTs. However, in the carbyne-containing composite material disclosed herein, it was confirmed for the first time that carbyne is formed inside the SWNT.

Note that the ratio (ΔC _H / ΔC) calculated as the contrast change of the hollow portion to the TEM contrast difference of the whole SWNT based on (A) in FIG. 8 is about 0.34, and based on (B) The calculated ratio (ΔC _H / ΔC) was about 0.35. It can be seen that, due to the presence of Calvin, for example, the contrast of the hollow portion of the CNT in the TEM image changes in a distinctly dark manner.

[Carbin Containing Composite Material: DWNT]
TEM observation was similarly performed about two DWNTs seen in the prepared CNT sheet after RIE and FE discharge, The result was shown to FIG. 9 (A) (B). Further, line scan analysis was performed in the direction orthogonal to the DWNT in the regions shown by squares in FIGS. 9A and 9B, and the results are shown in FIGS. 10A and 10B.

In FIG. 9A, the inner tube wall of DWNT is indicated by arrows a1 and b1. When observing FIG. 9 (A), a dark contrast extending streaky near the center of the tube wall was confirmed though it was faint. In the gradation profile of DWNT in FIG. 10 (A), double tube walls corresponding to two layers of CNTs were clearly observed as two pairs of deep valleys. Then, it was confirmed that one valley was formed in the vicinity of the center of the inner pair of tube walls indicated by arrows a1 and b1. From the gray scale profile, it was confirmed that the diameter of the inner tube of DWNT was about 1.2 nm, and the middle valley was located approximately at the center. In the DWNT of FIG. 9B, dark contrast was intermittently confirmed along the axial direction at the center of the inner pair of tube walls indicated by arrows a2 and b2. And also in the gradation profile of FIG. 10 (B), it has been confirmed that one valley is formed in the middle of the positions a2 and b2 corresponding to the inner tube wall. From the tone profile, it was confirmed that the diameter of the inner tube of DWNT was about 1.4 nm, and the valley in the middle appeared at a position slightly offset from the center. From the contrast of the TEM, it is considered that the substance present in the tube of DWNT is composed of light elements. Also, the contrast is sufficiently thinner than the SWNT tube wall observed in the same field of the TEM image. From the above results, it can be concluded that, in the carbyne-containing composite material disclosed herein, carbyne which is a linear carbon allotrope is also formed in the tube of DWNT.

Note that the ratio (ΔC _H / ΔC) calculated as the contrast change of the hollow portion to the TEM contrast difference of the whole DWNT based on (A) of FIG. 10 is about 0.19, and based on (B) The calculated ratio (ΔC _H / ΔC) was about 0.17. Although the ratio (ΔC _H / ΔC) became a rather small value due to the fact that the wall contrast was observed to be high due to the double wall of DWNT, for example, the hollow of the CNT in the TEM image due to the presence of Calvin The contrast ratio (ΔC _H / ΔC) of the portion is, for example, 0.16 or more, typically 0.17 or more.

[Carbin Containing Composite Material: MWNT]
Furthermore, the results of TEM observation of the three-layered MWNT found in the prepared CNT sheet after RIE and FE discharge are shown by squares in FIG. 11 (A) and in FIG. 11 (B). The results of line scan analysis in the direction perpendicular to the CNTs in the region are shown in FIG.
A three-layered CNT is shown in FIG. 11 (A), and the innermost tube wall is shown by arrows a1 and b1. In FIG. 11 (A), the streaky dark contrast was clearly confirmed in the middle of the three pairs of tube walls. In the gradation profile of MWNT in FIG. 11 (B), the triple tube wall corresponding to the three-layered CNT could be confirmed as roughly three pairs of valleys. And it has confirmed that one valley was deeply formed near the center of a pair of innermost tube walls shown by arrow a1 and b1. From the gray scale profile, it was confirmed that the diameter of the inner tube of the three-layer CNT was about 0.8 nm, and the middle valley was located approximately at the center. From the above results, it can be said that, in the carbyne-containing composite material disclosed herein, carbyne which is a linear carbon allotrope is formed also in the tube of the three-layered CNT. Note that the ratio (ΔC _H / ΔC) calculated based on FIG. 11 (B) was about 0.63.

[Carbin containing composites: multiple calvins]
Further, FIG. 12 (A) shows the result of similar TEM observation of DWNT found in the CNT sheet after RIE and FE discharge. Moreover, the result of having performed line scan analysis in the direction orthogonal to CNT in the area | region shown with the square in FIG. 12 (A) was shown in FIG. 12 (B).
The bent DWNT is shown in FIG. 12 (A), and the inner pair of tube walls are shown by arrows a1, b1. In this DWNT, about three streaks of bright contrast could be confirmed between the inner pair of tube walls. Then, when the gradation profile of FIG. 12B was confirmed, it could be confirmed that two valleys were formed between the positions a1 and b1 corresponding to the inner tube wall. That is, it is considered that the bright three contrasts in the TEM image appear due to the formation of two dark contrasts. From the tone profile, it is confirmed that the diameter of the inner tube of DWNT is about 1.5 nm, and the inner two valleys appear at the approximate center position of the inner tube with a distance of about 0.43 nm. It was done. From the contrast of the TEM, it is considered that the substance present in the tube of DWNT is composed of light elements. Also, the contrast is sufficiently thinner than the SWNT tube wall observed in the same field of the TEM image. From these facts, it has been confirmed that, in the carbin-containing composite material disclosed herein, a plurality of carbines which are linear carbon allotropes can be stably formed in the CNT. Further, from this result, it is expected that a plurality of calvins are formed in the CNT, although it is difficult to be observed by the TEM when the arrangement of the calvins is deviated from the center of the innermost CNT.

As mentioned above, although the carbyne content composite material concerning one embodiment of the present invention was explained, the carbyne content composite material concerning the present invention is not limited to the embodiment mentioned above, and various change is possible.

Claims

An aggregate of carbon nanotubes in which a plurality of carbon nanotubes are assembled;
With Calvin,
Including
A carbyne-containing composite material, wherein the carbyne is filled in 30% or more of the plurality of carbon nanotubes.
In the Raman spectrum measured by Raman spectroscopy:
Assuming that the peak intensity based on the G band is 1,
The carbine containing composite material of Claim 1 whose relative intensity of the peak based on LCC band is 0.4 or more.
The carbyne content composite material according to claim 1 or 2 in which said carbon nanotube which includes said carbine contains a single-walled carbon nanotube.
The calvin containing composite material according to claim 3 in which said carbon nanotube which encloses said calvin contains ten single-walled carbon nanotubes several 10% or more.
The carbyne-containing composite material according to any one of claims 1 to 4, wherein at least a part of the carbon nanotubes includes two or more carbines in a direction orthogonal to the axial direction of the carbon nanotubes.
An article comprising the carbyne-containing composite material according to any one of claims 1 to 5.
Preparing a carbon nanotube aggregate in which a plurality of carbon nanotubes are assembled and the G / D ratio is 25 or more,
Applying a voltage at which at least electric field electron emission occurs to the carbon nanotube aggregate;
A method of producing a carbin containing composite material, comprising: