JP2011051880A - Method and device for producing carbon nanostructure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique for carbon nanostructure production based on a new principle with which it is possible to produce carbon nanostructures in an ordinary-temperature inert-gas atmosphere in atmospheric pressure. <P>SOLUTION: The method for producing carbon nanostructure comprises setting a target material in a chamber, irradiating the target material in an ordinary-temperature inert-gas atmosphere in atmospheric pressure with continuous electron beams emitted from an electron accelerator, thereby melting and gasifying the target material, subsequently cooling the gasified target raw material to form a high-temperature gas in which graphite and a catalyst metal coexist, maintaining the high-temperature coexistence gas for a certain period, and then cooling the coexistence gas to thereby yield carbon nanostructures. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a carbon nanostructure manufacturing method and a manufacturing apparatus based on a new principle.

  A carbon nanotube has a nanoscale and is a material that has been very researched and developed in recent years because of its excellent mechanical properties, electrical properties, optical properties, and the like. Carbon nanotubes are generally made by a CVD method, an arc discharge method, a laser ablation method, or the like.

  Among such production methods, for example, Patent Document 1 discloses that a graphite target containing a metal catalyst is under an accelerating voltage of 10 kV in a jet atmosphere of an inert gas or hydrogen gas preheated to 700 to 1200 ° C. A technique for producing a carbon nanotube by irradiating a pulsed electron beam is disclosed. The pressure in the chamber is reduced to 1 to 10 mbar (10 to 100 Pa).

However, in such a conventional method for producing carbon nanotubes, it is necessary to produce in an atmosphere in which an inert gas such as He, Ar, or H ₂ is heated to a high temperature, or in a reduced pressure state.

  On the other hand, depending on the production method, carbon nanotubes express different and unique properties, and therefore, a method for creating carbon nanotubes that express new physical properties is expected.

  Carbon nanohorns are the same carbon nanostructure as carbon nanotubes, and are manufactured by an arc discharge method or the like. In this case, it is known that a large number of carbon nanohorns can be obtained as a chestnut-shaped aggregate in which the apexes are gathered outward. This carbon nanohorn has a horn shape at the tip, and metal nanoparticles are easily attached to the outer wall, and gas and chemicals are easily taken into the interior. ing.

WO2005 / 069700

  SUMMARY OF THE INVENTION In view of the actual situation of the prior art, the present invention produces carbon nanotubes or carbon nanostructures composed of carbon nanotubes and carbon nanohorns at room temperature and atmospheric pressure, not in an atmosphere heated with an inert gas. An object of the present invention is to provide a carbon nanostructure manufacturing method and manufacturing apparatus based on a new principle.

  In order to solve the above problems, the present invention firstly comprises a step of setting a target raw material containing graphite as a base material and containing a catalytic metal in a chamber, and an inert gas at atmospheric pressure and at room temperature. In the atmosphere, the target raw material is irradiated with a continuous electron beam emitted from the electron accelerator to melt and gasify the target raw material, and the gasified target raw material is cooled to a predetermined temperature to thereby convert the graphite and catalyst. A carbon nanostructure comprising: a step of forming a coexisting high-temperature gas state with a metal; and a step of generating the carbon nanostructure by further cooling after maintaining the coexisting high-temperature gas state for a certain period of time A manufacturing method is provided.

  Secondly, a step of setting a target raw material containing graphite as a base material in a chamber, and a continuous discharge from an electron accelerator in an atmosphere composed of an inert gas at normal pressure and at room temperature. By irradiating the target raw material with an electron beam, the target raw material is melted and gasified, and the gasified target raw material is heated in a first cooling chamber heated to a predetermined temperature lower than the temperature in the chamber. The step of forming a coexisting hot gas state of graphite and catalytic metal by transferring and cooling to a predetermined temperature while being refluxed, and maintaining the coexisting hot gas state for a certain period of time in the first cooling chamber, and further cooling A step of generating a carbon nanostructure by the method, and transferring the generated carbon nanostructure to the second cooling chamber. Provides a step of cooling to room temperature, the method of producing a carbon nanostructure which is characterized by the step of recovering the second carbon nanostructure was allowed to cool to room temperature in the cooling chamber.

  Third, setting a container-like target holder containing a target material formed by stacking a catalyst metal-containing tablet containing graphite as a base material and a graphite tablet made of graphite in the chamber; and The target raw material is melted and gasified by irradiating the target raw material with a continuous electron beam emitted from an electron accelerator in an atmosphere of an inert gas at normal temperature and at normal temperature. The target material is sent to the coexistence gas recirculation chamber through the gas transfer pipe to form a coexistence gas state and maintain the coexistence gas state for a certain period of time while refluxing the coexistence gas recirculation chamber; And a step of recovering the generated carbon nanostructure To provide a manufacturing method of a carbon nanostructure.

  Fourth, in any one of the first to third inventions, a carbon nanostructure characterized by using an alloy made of Ni, Fe, Co, Cr, or any combination thereof as a catalyst metal. A manufacturing method is provided.

Fifth, in any one of the first to fourth inventions, there is provided a carbon nanostructure manufacturing method characterized by using Ar, He, N ₂ or a mixed gas thereof as an inert gas. To do.

  Sixth, in any one of the first to fifth inventions, a method for producing a carbon nanostructure in which the carbon nanostructure is a carbon nanotube or a carbon nanotube and a carbon nanohorn is provided.

  Seventh, a chamber in which a target raw material containing graphite as a base material containing graphite is set, an inert gas supply means for supplying an inert gas at room temperature into the chamber, and an electron in the target raw material under atmospheric pressure By irradiating the beam, an electron accelerator that emits an electron beam in order to melt and gasify the target material, and the gasified target material is cooled to a predetermined temperature, so that a coexisting high-temperature gas state of graphite and catalyst metal can be obtained. An apparatus for producing a carbon nanostructure is provided, characterized by having means for forming and maintaining the coexisting high-temperature gas state for a certain period of time, and further cooling to generate a carbon nanostructure.

  Eighth, a chamber in which a target raw material containing graphite as a base material containing graphite is set, an inert gas supply means for supplying an inert gas at room temperature into the chamber, and an electron in the target raw material under atmospheric pressure. A gasified target material comprising an electron accelerator that emits an electron beam to melt and gasify the target material by irradiating the beam, and a heating means for heating the interior to a predetermined temperature lower than the temperature in the chamber By cooling while refluxing, a coexisting high temperature gas state of graphite and the catalytic metal is formed, and after maintaining the coexisting high temperature gas state for a certain period of time, it is further cooled to generate a carbon nanostructure. A first cooling chamber, a second cooling chamber for further cooling the carbon nanostructure formed in the first cooling chamber to room temperature, Providing an apparatus for manufacturing a carbon nanostructure which is characterized by having a carbon nanostructure recovery means for recovering the cooling chamber carbon nanostructure was allowed to cool to room temperature in the.

  Ninth, a chamber in which a container-like target holder containing a target material formed by laminating a graphite tablet made of graphite as a base material and containing a catalyst metal-containing graphite tablet and a graphite tablet made of graphite is set; An inert gas supply means for supplying an inert gas at room temperature, and an electron accelerator that emits an electron beam to melt and gasify the target material by irradiating the target material with an electron beam under atmospheric pressure Then, the gasified target material is sent to the high temperature gas reaction chamber via the gas transfer pipe to form a coexisting high temperature gas state and maintain the coexisting high temperature gas state for a certain period of time while refluxing the coexisting high temperature gas in the high temperature gas reaction chamber. And means for further cooling to produce carbon nanostructures, Providing an apparatus for manufacturing a carbon nanostructure which is characterized in that it comprises means for recovering the carbon nanostructure.

  Tenth, in any one of the seventh to ninth inventions, a carbon nanostructure manufacturing apparatus is provided in which the carbon nanostructure is a carbon nanotube, or a carbon nanotube and a carbon nanohorn.

  According to the present invention, since the method or means as described above is adopted, carbon nanotubes, or carbon nanostructures composed of carbon nanotubes and carbon nanohorns at room temperature and atmospheric pressure, not in an atmosphere in which an inert gas is heated. It is possible to produce carbon nanostructures based on a new principle.

It is a conceptual diagram which shows typically an example of the manufacturing apparatus of the carbon nanostructure by this invention. It is a figure which shows the example of the output of an electron accelerator. It is a figure which shows the electron micrograph (TEM) image of the single wall carbon nanotube manufactured with the apparatus of FIG. It is a figure which shows the electron micrograph (TEM) image of the multi-walled carbon nanotube manufactured with the apparatus of FIG. It is a conceptual diagram which shows typically another example of the manufacturing apparatus of the carbon nanostructure by this invention. It is a figure which shows the example of the output of an electron accelerator. It is a figure which shows the example of the output of an electron accelerator. It is a conceptual diagram which shows typically another example of the manufacturing apparatus of the carbon nanostructure by this invention. It is a conceptual diagram which shows typically another example of the manufacturing apparatus of the carbon nanostructure by this invention. It is a conceptual diagram which shows the motion of the coexisting hot gas in a hot gas reaction chamber. It is a figure which shows the example of the output of an electron accelerator. It is a figure which shows the measurement result of the Raman spectrum of the soot collected from the filter. It is a figure which shows the transmission electron microscope (TEM) photograph of the extract | collected soot. It is a figure which shows another transmission electron microscope (TEM) photograph of the extract | collected soot. It is a figure which shows another transmission electron microscope (TEM) photograph of the extract | collected soot. It is a figure which shows another transmission electron microscope (TEM) photograph of the extract | collected soot. It is a figure which shows the enlarged photograph of FIG.

The method for producing a carbon nanostructure according to the present invention basically includes the following steps.
(A) A step of setting a target raw material containing a catalytic metal using graphite as a base material in a chamber;
(B) A step of melting and gasifying the target raw material by irradiating the target raw material with a continuous electron beam emitted from an electron beam accelerator in an atmosphere consisting of an inert gas at room temperature under atmospheric pressure,
(C) forming a coexisting high-temperature gas state of graphite and catalytic metal by cooling the gasified target raw material to a predetermined temperature;
(D) A step of generating the carbon nanostructure by further cooling after maintaining the coexisting high-temperature gas state for a certain period of time.
Here, the carbon nanostructure may be a single-walled or multi-walled carbon nanotube, a mixture thereof, or a carbon nanohorn.

  In the present invention, as the target material, a material containing graphite as a base material and containing a catalyst metal is used. For example, graphite and catalyst metal can be used in powder form, and a mixture of these can be formed into pellets to form a target material, but is not limited thereto. As the catalyst metal, Ni, Fe, Co, Cr, or a mixture thereof can be used. The amount of the catalytic metal is desirably an amount suitable for promoting the growth of the carbon nanostructure, and is, for example, about 1 to 5% by weight.

As the inert gas, Ar, He, N ₂ or a mixed gas thereof can be used at room temperature. The inert gas may be supplied into the chamber in advance before manufacturing the carbon nanostructure, or may be supplied at a constant flow rate, for example, up to 300,000 sccm when the carbon nanostructure is manufactured. Further, depending on the case, the flow rate may be changed.

  The chamber is made of a heat-resistant material such as stainless steel (Russian model 12H18N10T) and has a sealed structure.

  A continuous beam is used as the electron beam applied to the target material. In the present invention, an electron beam is generated using an accelerator. As the electron accelerator, for example, an acceleration voltage of 1.4 MeV and an output that can be adjusted between 0 to 40 kW can be used, and the output is adjusted by a current. In this case, the irradiation time is preferably about 1 to 60 minutes for good growth of the carbon nanostructure.

  When the target material is irradiated with an electron beam, it is presumed that the target material is melted and gasified to form a mixed plasma gas of the inert material and the gasified target material. The temperature at this time is about 5000 to 6000 ° C.

  The gasified target raw material is cooled and becomes a coexisting high-temperature gas state of graphite and catalytic metal, and the temperature at this time is 1000 to 1400 ° C. This coexisting high-temperature gas state is maintained for about 30 to 60 minutes, and carbon nanotubes, or carbon nanotubes and carbon nanohorns are generated by gas phase synthesis. Depending on the type of catalytic metal, the carbon nanotube may be a single layer, a multilayer of two or more layers, or a mixture thereof. A carbon nanohorn may be generated together with the carbon nanotube.

  Next, an example of a carbon nanostructure manufacturing apparatus according to the present invention will be described. FIG. 1 is a conceptual diagram schematically showing the carbon nanostructure manufacturing apparatus of this example. In the figure, reference numeral 11 denotes a chamber, which is made of a heat-resistant material such as stainless steel (Russian model 12H18N10T) and can be made into a sealed structure. In the chamber 11, the target raw material 12 is supported by a support base 13. The chamber 11 has a water-cooled wall surface 14. The wall surface 14 is made of stainless steel (Russian model 12H18N10T). The cooling water enters the wall surface from the pipe 15, and the heated water after cooling is discharged from the pipe 16. An electron accelerator 17 is disposed above the chamber 11 so that the target material 12 can be irradiated with an electron beam 18. A pipe 19 for supplying helium as an inert gas into the chamber 11 is provided below the chamber 11. In addition, a pipe 20 and a vacuum pump 21 for once replacing air and helium are provided. 22 and 23 are valves, 26 is a flow meter, 24 is a thermocouple, and 25 is a pipe for supplying nitrogen to the outlet portion of the electron accelerator 17.

  The chamber 11 of the prototype carbon nanostructure manufacturing apparatus has a cylindrical shape, a diameter of 170 mm, a height of 150 mm, and a capacity of 3.4 L. As target raw materials, Co (purity 99.8%) 2.4% by weight, Ni (purity 99.8%) 2.4% by weight, remaining graphite (model MPG-6: manufactured by Novocherkasskiy electrod plant, Russia: purity 99. 96%) mixed powder was used as a circular tablet having a diameter of 12 mm and a thickness of 4 mm with a molding pressure of 20 MPa. As the electron accelerator 17, an ELV type electron accelerator (energy 1.4 MeV) was used. Helium was supplied at a flow rate of 0.5 L / sec. The output of the electron accelerator 17 was as shown in FIG. The coexisting high temperature gas state was maintained for 3 minutes. The electron microscope (TEM) image of the carbon nanotube obtained as a result is shown in FIG. It can be seen that single-walled carbon nanotubes are formed. Moreover, it was confirmed by the Raman analysis that the carbon nanotube was obtained.

  Next, another example of the carbon nanostructure according to the present invention will be described. FIG. 5 is a conceptual diagram schematically showing another carbon nanostructure manufacturing apparatus. In the figure, reference numeral 31 denotes a chamber, which is made of a heat-resistant material such as stainless steel (Russian model 12H18N10T) and can be made into a sealed structure. In the chamber 31, the target raw material 32 is supported by a support base 33. In this example, a cylindrical screen 34 is provided so as to surround the target material 32, a plurality of ring-shaped members 35 are attached to the inside of the screen 34, and a cover 36 is attached to the upper part. This configuration is for making a space in which helium does not circulate in order to manufacture the carbon nanostructure more efficiently and for facilitating the recovery of the manufactured carbon nanostructure. An electron accelerator 37 is disposed above the chamber 31 so that the target material 32 can be irradiated with an electron beam 38. In this example, two pipes 39 and 40 for supplying helium into the chamber 31 are provided on the side and the upper side of the chamber 31.

  The capacity of the chamber 31 of the prototype carbon nanostructure manufacturing apparatus is 3.4L. As target raw materials, Co (purity 99.8%) 2.0% by weight, Ni (purity 99.8%) 3.0% by weight, remaining graphite (model MPG-6: manufactured by Novocherkasskiy electrod plant, Russia: purity 99. 96%) of the mixed powder was used as a 12 mm diameter circular tablet with a molding pressure of 20 MPa. The total thickness of the sample is 21 mm. As a target material, a mixed powder of Ni (purity 99.8%) 5.0% by weight and the remaining graphite (model MPG-6: manufactured by Russia Novocherkasskiy electrod plant: purity 99.96%) is 12 mm at a molding pressure of 20 MPa. Six round tablets having a diameter were used in piles. The total thickness of the sample is 24 mm. The above two samples were irradiated with an electron beam. As the electron accelerator 37, an ELV type electron accelerator (energy 1.4 MeV) was used. Helium was supplied from two locations at a flow rate of 0.3 L / sec. The outputs of the two electron accelerators 37 are as shown in FIGS. The coexisting high temperature gas state was maintained for 3 minutes. In both cases, it was confirmed that carbon nanotubes were obtained, but with a target material using Ni (purity 99.8%) 5.0% as a catalyst, an electron microscope (TEM) image of the carbon nanotubes is shown in FIG. As can be seen, multi-walled carbon nanotubes are formed.

  Next, still another example of the carbon nanostructure manufacturing apparatus according to the present invention will be described. FIG. 8 is a conceptual diagram schematically showing another example of the carbon nanostructure manufacturing apparatus. This example is an example suitable for mass production. In the figure, reference numeral 41 denotes a chamber, which is made of stainless steel (Russian model 12H18N10T) and can have a sealed structure. A crucible 43 in which the target raw material 42 is accommodated is set in the chamber 41. The inside of the chamber 41 is set to atmospheric pressure, and an inert gas storage tank 45 is connected to a part of the side wall via a pipe 44. An inert gas 46 such as helium is stored in the inert gas storage tank 45 and is supplied to the chamber 41 when the carbon nanostructure is manufactured. An electron accelerator 47 is disposed above the chamber 41 so as to irradiate the target material 42 with an electron beam 48. As the electron accelerator 47, the same one as described above can be used. The output is adjusted by current.

  On the other hand, the first cooling chamber 50 is connected to another portion of the side wall of the chamber 41 through a pipe 49. The first cooling chamber 50 is made of stainless steel (Russian model 12H18N10T) and has a sealed structure, and is air-cooled from the outside when the carbon nanostructure is manufactured. A quartz tube 51 is disposed in the first cooling chamber 50. Around the quartz tube 51, a heater 54 for cooling the high-temperature evaporating gas, which is a gasified target material from the chamber 41, to an appropriate temperature is installed. The cooled gas is a coexisting high-temperature gas of graphite and catalytic metal, and the temperature thereof is about 1000 to 1400 ° C. The heater 54 cools the high-temperature evaporating gas inside the quartz tube 51, so that the temperature inside the quartz tube 51 is, for example, The temperature is kept at about 1000 ° C. In the 1st cooling chamber 50, a coexistence high temperature gas state is maintained for 30 to 60 minutes, and a carbon nanostructure is produced | generated.

A pipe 55 is provided in the lower part of the wall surface of the first cooling chamber 50 as shown in the figure, and is connected to the second cooling chamber 56. The second cooling chamber 56 is provided to cool the carbon nanostructure to room temperature. A pipe 57 is further connected to the wall surface of the second cooling chamber 56 and is connected to the filter chamber 58. In the filter chamber 58, the inert gas is exhausted to the outside through the pipe 60 by the filter 59 installed inside. Carbon nanostructures are collected. A fan 61 is installed for exhausting the inert gas.
In the figure, 62 to 64 are valves.

  When the carbon nanostructure is manufactured using the apparatus of FIG. 8, first, the target raw material 42 is accommodated in the crucible 43 and set in the chamber 41. An inert gas 46 is supplied into the chamber 41 from the inert gas storage tank 45 at a constant flow rate, for example. At this time, the valve 62 is closed. An electron beam 48 is irradiated onto the target material 42 continuously from the electron accelerator 47 at a predetermined acceleration voltage for a predetermined time. By irradiation with the electron beam 48, the inert gas 46 is turned into plasma, the target material 42 is melted and evaporated, and a high-temperature evaporation gas is formed by the plasma of the inert gas 46 and the evaporation gas of the target material 42. This high-temperature evaporating gas is about 5000 to 6000 ° C. When the irradiation of the electron beam 48 for a predetermined time is completed and the high-temperature mixed evaporating gas is formed, the valve 62 is opened and the high-temperature evaporating gas is sent to the first cooling chamber 50. At that time, the valve 63 is closed.

  The high-temperature evaporative gas sent to the first cooling chamber 50 is refluxed inside. The entire first cooling chamber 50 is air-cooled, and the quartz tube 51 provided in the first cooling chamber 50 is maintained at a temperature lower than that of the high-temperature evaporating gas by the heater 54, for example, 1000 ° C. The refluxing high-temperature evaporating gas is air-cooled and cooled in the quartz tube 51 to become a coexisting high-temperature gas of graphite and catalyst metal, and the temperature is 1000 to 1400 ° C. By maintaining this coexisting high-temperature gas state for about 30 to 60 minutes, the carbon nanostructure grows.

  When the generation of the carbon nanostructure is finished in the first cooling chamber 50, the valve 63 is opened, and the inert gas 46 containing the carbon nanostructure is sent to the second cooling chamber 56. At this time, the valve 64 is closed. The high temperature inert gas 46 containing the carbon nanostructure is cooled to room temperature in the second cooling chamber 56.

  Thereafter, the valve 64 is opened, and a room temperature inert gas 46 containing carbon nanostructures is sent to the filter chamber 58. In the filter chamber 58, the carbon nanostructure and the inert gas 46 are separated by the filter 59, and the inert gas 46 is discharged to the outside through the pipe 60 to obtain a desired carbon nanostructure.

  In the above description, the carbon nanostructures are collected in the filter chamber 58. However, a cyclone apparatus (dry type) or a floating sorting apparatus (wet type) may be used. In addition, known methods for separating and recovering carbon nanostructures can also be used. When using a dry cyclone apparatus, it is preferable to use Ar, He, or a mixed gas thereof instead of air. Furthermore, a specific product (carbon nanotube, carbon nanohorn, etc.) in the carbon nanostructure may be performed in a step different from the generation and recovery.

  Further, the crucible 43 into which the target raw material 42 is placed may be configured to be set so as to be rotatable in the chamber 41. In this way, further mass production can be expected.

  Next, still another example of the carbon nanostructure manufacturing apparatus according to the present invention will be described. FIG. 9 is a conceptual diagram schematically showing another example of the carbon nanostructure manufacturing apparatus. This example is an example suitable for a composite of carbon nanotube production and carbon nanohorn production. In the figure, reference numeral 71 denotes a chamber, which is made of stainless steel (Russian model 12H18N10T) and can be made into a sealed structure. A container-type target holder 73 in which a target raw material 72 is accommodated is set in the chamber 71. The target raw material 72 is configured by laminating a catalyst metal-containing graphite tablet 74 made of graphite as a base material and containing the aforementioned catalyst metal, and a graphite tablet 75. In this example, three tablets are alternately stacked. The inside of the chamber 71 is set to atmospheric pressure, and a pipe 76 and a pipe 79 for supplying helium, which is an inert gas, are disposed on the side wall and the bottom, and a pressure gauge 77 and a pressure gauge 80, a valve 78 and a valve 81 are provided. Each is provided. A pipe 82 for supplying nitrogen gas for helium shielding is disposed above the chamber 71, and a pressure gauge 83 and a valve 84 are provided in the pipe 82. An electron accelerator 85 is disposed above the chamber 71 so as to irradiate the target material 72 with an electron beam 86. As the electron accelerator 85, the same one as described above can be used. The output is adjusted by current. In addition, 87 is a U-shaped pressure gauge, 88 is a centering ring, and 89 is a target enclosure box.

  On the other hand, reference numeral 90 in the figure denotes a cylindrical high-temperature gas reaction chamber that communicates with the chamber 71 through a connecting metal pipe 91. A gas transport pipe 92 made of heat-resistant graphite is inserted into the connecting metal pipe 91, and the target enclosure box 89 in the chamber 71 and the high-temperature gas reaction chamber 90 communicate with each other. Further, a product outlet pipe 94 is connected to the lower part of the hot gas reaction chamber 90 and connected to the product recovery chamber 93. A filter 95 for collecting and collecting the product is attached to the tip of the outlet pipe 94. It is attached. In the figure, 96 is an exhaust pump.

  When the carbon nanostructure is manufactured using the apparatus of FIG. 9, first, the graphite tablet 75 and the catalyst metal-containing graphite tablet 74 are laminated, accommodated in the container-type target holder 73, and set in the chamber 71. Next, helium gas is introduced into the chamber 71 from the side wall and the lower portion of the chamber 71 through the pipe 76 and the pipe 79, and the air in the chamber is removed. Then, nitrogen gas is sent through a pipe 82 and sealed so that helium gas in the chamber is not released from the upper part of the chamber. Next, the target raw material 72 is continuously irradiated with the electron beam 86 at a predetermined acceleration voltage from the electron accelerator 85 for a predetermined time. At that time, the inside of the chamber 71 is warmed for a predetermined time with a low output in advance. Thereafter, while the exhaust pump 96 is operated, the output of the electron accelerator 85 is increased, and the target material 72 is continuously irradiated with the electron beam 86. By continuous irradiation of the electron beam 86, the helium gas is turned into plasma, the target material 72 is melted and evaporated, and a high-temperature mixed plasma of the helium gas plasma and the evaporated gas of the target material 72 is formed. The high temperature mixed plasma is about 5000 to 6000 ° C. When the electron beam 86 is irradiated for a predetermined time to form a high-temperature evaporating gas, it is sent from the gas transfer pipe 92 to the high-temperature gas reaction chamber 90. The high-temperature evaporative gas sent to the high-temperature gas reaction chamber 90 is a coexisting high-temperature gas of graphite and catalyst metal. In the high-temperature gas reaction chamber 90, the wall surface of the high-temperature gas reaction chamber 90 is cylindrical. The gas swirls and flows along the cylindrical wall. After the coexisting high temperature gas state is maintained for a certain period of time, the gas moves downward. FIG. 10A is a perspective view schematically and FIG. 10B is a schematic cross-sectional view. The zone indicated by the arrow in FIG. 10A is a zone in which the coexisting high-temperature gas swirls and is maintained at a predetermined temperature for a certain time. After the coexisting high-temperature gas is maintained for a certain time in this zone, the carbon nanostructure is generated by cooling. The generated carbon nanostructure is discharged from the outlet pipe 94, attached to the filter 95 in the product recovery chamber 93, and recovered.

Next, specific experimental examples will be described.
The apparatus configuration and the like will be described. The chamber 71 has a cylindrical shape, is made of heat resistant stainless steel (Russian model 12H18N10T), and can have a sealed structure. The dimensions of the chamber 71 were a diameter of 150 mm, a height of 200 mm, and a capacity of about 3L.
The raw material target 72 was formed by alternately stacking three catalytic metal-containing graphite tablets 74 and three cut and purified graphite tablets 75, and the total height was 30 mm. The catalyst metal-containing graphite tablet 74 is 2.5% by weight of Co (purity 99.8%), 2.5% by weight of Ni (purity 99.8%), remaining graphite (model MPG-6: manufactured by Novocherkasskiy electrod plant, Russia) : 99.96% purity) of the mixed powder was produced as a circular tablet having a diameter of 20 mm, a thickness of 5 mm, a density of 2.0 g / cm ³ and a weight of 4 g at a molding pressure of 200 atm (about 20 MPa). The graphite tablet 75 was made of graphite (German reactor graphite Henschke CGD: purity 99.99% or more), and ^three circular tablets having a diameter of 20 mm, a thickness of 5 mm, and a density of 1.8 g / cm 3 were produced.
The container-type target holder 73 was made of graphite (reactor graphite Henschke CGD made in Germany: purity 99.99% or more), and was manufactured with an outer diameter of 35 mm, an inner diameter of 21 mm, and a height of 50 mm.
The target enclosure box 89 was made of heat-resistant graphite (model MDG-6: Russian Novocherkasskiy electrod plant, purity 99.75% or more), an outer diameter of 120 mm, an inner diameter of 100 mm, and a height of 150 mm.
As the electron accelerator 85, an ELV type electron accelerator (energy: 1.4 MeV) was used. The output of the electron accelerator 85 was as shown in FIG.
The connecting metal pipe 91 was made of stainless steel (Russian model 12X18H10T) having an outer diameter of 45 mm, an inner diameter of 40 mm, and a length of 260 mm.
The gas carrying pipe 92 was made of heat-resistant graphite (model MDG-6: Russian Novocherkasskiy electrod plant, purity 99.75% or more), an outer diameter of 39 mm, an inner diameter of 23 mm, and a length of 300 mm.

Using the apparatus configured as described above, the carbon nanostructure was manufactured as follows.
First, three graphite tablets 75 and three catalytic metal-containing graphite tablets 74 produced above are alternately stacked, and a total of six tablets are accommodated in the container-type target holder 73 as target raw materials 72, and are stored in the chamber 71. I set it. Next, helium gas was introduced into the chamber 71 to exclude the air in the chamber. Thereafter, nitrogen gas was supplied and sealed so that helium gas in the chamber did not flow out from the upper part of the chamber. The flow rates of helium gas and nitrogen gas were 0.3-0.5 L / sec. The exhaust pump 96 was activated. The helium gas that has entered the chamber 71 from the bottom of the chamber 71 rises outside the target enclosure gas 89, merges with the helium gas from the side surface of the chamber 71, and enters the inside of the target enclosure box 89 from the upper hole of the target enclosure box 89. to go into.

  In this state, the electron accelerator 85 was operated, and the inside of the chamber 71 was warmed at an output of 4.2 KW for 5 minutes. The surplus pressure in the chamber before the electron beam irradiation by the exhaust pump 96 (pressure of the supply gas + exhaust pressure by the exhaust pump), that is, the difference between the atmospheric pressure of 1 atm and the pressure in the chamber is 40 Pa according to the U-shaped pressure gauge 87. The pressure inside the chamber was 1.000394 atmospheres.

  Next, the output of the electron accelerator 85 was increased to 11.2 kW, and the target material 72 was irradiated with the electron beam 86 for 20 minutes. By irradiation with the electron beam 86, the helium gas is turned into plasma, and the target 72 is also melted and evaporated by the electron beam 86 to be turned into plasma, and the mixed high-temperature plasma is a gas transport pipe extending from the target enclosure box 89 to the hot gas reaction chamber 90. It enters into the high temperature reaction chamber 90 as a coexisting high temperature gas through 92. Thereafter, the operation of the electron accelerator 85 was stopped. The coexisting hot gas is naturally cooled in the hot gas reaction chamber 90, but carbon, Ni, and Co coexist in a predetermined zone (indicated by an arrow in FIG. 10A) of 1000 to 1400 ° C. in the cooling process. The carbon nanostructure grows.

  Thereafter, the soot in the filter 95, the hot gas reaction chamber 90, the gas transfer pipe 92, and the chamber 71 was collected. As a result, soot has adhered to the entire surface of the filter 95, and there are also soot on the inner wall and lid of the high-temperature gas reaction chamber 90. Although there is a considerable amount of soot on the gas transport pipe 92, the surface of the filter 95 and the high temperature Less than in the gas reaction chamber 90. There were almost no wrinkles in the target enclosure box 89. Thereby, the production | generation of the carbon nanostructure (carbon nanotube and carbon nanohorn) in the hot gas reaction chamber 90 was confirmed.

  FIG. 12 shows the measurement results of the Raman spectrum of soot collected from the filter 95. From this figure, it was confirmed that carbon nanohorns were obtained together with carbon nanotubes.

  Moreover, the transmission electron microscope (TEM) photograph of the cocoon extract | collected to FIGS. 13-17 is shown. In FIG. 13, relatively long multi-walled carbon nanotubes are observed. In FIG. 14, single-walled carbon nanotubes and multi-walled carbon nanotubes are observed. In FIG. 15, carbon nanotubes containing another substance inside are observed. In FIG. 16, single-walled carbon nanohorns are observed. FIG. 17 is an enlarged view of FIG.

DESCRIPTION OF SYMBOLS 11 Chamber 12 Target sample 13 Support stand 17 Electron accelerator 18 Electron beam 31 Chamber 32 Target raw material 34 Screen 35 Ring-shaped member 36 Cover 37 Electron accelerator 38 Electron beam 41 Chamber 42 Target raw material 43 Crucible 46 Inert gas 47 Electron accelerator 48 Electron beam 50 First cooling chamber 51 Quartz tube 54 Heater 56 Second cooling chamber 58 Filter chamber 59 Filter 61 Fan 71 Chamber 72 Target raw material 73 Container type target holder 74 Catalytic metal-containing graphite tablet 75 Graphite tablet 85 Electron accelerator 86 Electron beam 89 Target enclosure Box 90 Hot gas reaction chamber 92 Gas transfer pipe 95 Filter 96 Exhaust pump

Claims (10)

A step of setting a target raw material containing catalytic metal using graphite as a base material in a chamber;
Irradiating the target material with a continuous electron beam emitted from the electron accelerator in an atmosphere consisting of an inert gas at room temperature under atmospheric pressure, and melting and gasifying the target material;
Forming a coexisting hot gas state of graphite and catalytic metal by cooling the gasified target raw material to a predetermined temperature;
A method for producing a carbon nanostructure, comprising: maintaining the coexisting high-temperature gas state for a predetermined time, and further generating a carbon nanostructure by further cooling. A step of setting a target raw material containing catalytic metal using graphite as a base material in a chamber;
Irradiating the target material with a continuous electron beam emitted from the electron accelerator in an atmosphere consisting of an inert gas at room temperature under atmospheric pressure, and melting and gasifying the target material;
The gasified target raw material is transferred to a first cooling chamber whose interior is heated to a predetermined temperature lower than the temperature in the chamber, and is cooled to a predetermined temperature while being refluxed, whereby a coexisting high-temperature gas of graphite and catalyst metal Forming a state; and
A step of generating a carbon nanostructure by further cooling after maintaining the coexisting hot gas state for a certain time in the first cooling chamber;
Transferring the generated carbon nanostructure to the second cooling chamber and further cooling to room temperature;
A method for producing a carbon nanostructure, comprising a step of recovering a carbon nanostructure cooled to room temperature in a second cooling chamber. Setting a container-like target holder containing a target material formed by stacking a catalyst metal-containing tablet containing graphite as a base material and a graphite tablet made of graphite in the chamber; and
Irradiating the target material with a continuous electron beam emitted from the electron accelerator in an atmosphere consisting of an inert gas at room temperature under atmospheric pressure, and melting and gasifying the target material;
The carbon nanostructure is made by sending the gasified target material to the coexistence gas recirculation chamber through the gas transport pipe to form a coexistence gas state and refluxing the coexistence gas recirculation chamber for a certain period of time. Generating
A method for producing a carbon nanostructure, comprising a step of recovering the generated carbon nanostructure.   The method for producing a carbon nanostructure according to any one of claims 1 to 3, wherein the catalyst metal is Ni, Fe, Co, Cr, or an alloy made of any combination thereof. The method for producing a carbon nanostructure according to any one of claims 1 to 4, wherein Ar, He, N ₂ or a mixed gas thereof is used as the inert gas.   The method for producing a carbon nanostructure according to any one of claims 1 to 5, wherein the carbon nanostructure is a carbon nanotube, or a carbon nanotube and a carbon nanohorn. A chamber in which a target raw material containing a catalyst metal is set using graphite as a base material;
An inert gas supply means for supplying an inert gas at room temperature into the chamber;
An electron accelerator that emits an electron beam to melt and gasify the target material by irradiating the target material with an electron beam under atmospheric pressure;
The gasified target material is cooled to a predetermined temperature, and a coexisting hot gas state of graphite and catalytic metal is formed. After the coexisting hot gas state is maintained for a certain period of time, it is further cooled to generate a carbon nanostructure. An apparatus for producing a carbon nanostructure characterized by comprising means for causing A chamber in which a target raw material containing a catalyst metal is set using graphite as a base material;
An inert gas supply means for supplying an inert gas at room temperature into the chamber;
An electron accelerator that emits an electron beam to melt and gasify the target material by irradiating the target material with an electron beam under atmospheric pressure;
Equipped with a heating means to heat the interior to a predetermined temperature lower than the temperature in the chamber, and by cooling the gasified target material while refluxing, a coexisting high temperature gas state of graphite and catalytic metal is formed, and the coexisting high temperature A first cooling chamber for maintaining the gas state for a certain period of time and further cooling to generate a carbon nanostructure;
A second cooling chamber for further cooling the carbon nanostructure produced in the first cooling chamber to room temperature;
An apparatus for producing a carbon nanostructure comprising carbon nanostructure recovery means for recovering a carbon nanostructure cooled to room temperature in a second cooling chamber. A chamber in which a container-like target holder containing a target raw material formed by laminating a graphite tablet containing a catalytic metal containing a catalytic metal containing graphite and a graphite tablet made of graphite is set;
An inert gas supply means for supplying an inert gas at room temperature into the chamber;
An electron accelerator that emits an electron beam to melt and gasify the target material by irradiating the target material with an electron beam under atmospheric pressure;
The gasified target raw material was sent to the high temperature gas reaction chamber through the gas transfer pipe to form a coexisting high temperature gas state, and the coexisting high temperature gas was refluxed in the high temperature gas reaction chamber and maintained for a certain period of time. After that, means for further cooling to generate carbon nanostructures,
An apparatus for producing a carbon nanostructure, comprising means for recovering the generated carbon nanostructure.   The carbon nanostructure manufacturing apparatus according to any one of claims 7 to 9, wherein the carbon nanostructure is a carbon nanotube, or a carbon nanotube and a carbon nanohorn.