JP2009502702A - Method and apparatus for producing nanostructures - Google Patents

Abstract

A method and apparatus for producing a nanostructure is provided.
A method for producing a nanostructure includes passing a gas containing nanostructure components through one or more hollow cathode reactors to produce a nanostructure, collecting the nanostructure, and Removing by-products from the exhaust gas together with oxidizing gas through one or more hollow cathode reactors.
[Selection] Figure 1

Description

  The present invention relates to the production of nanostructures, and in a preferred embodiment thereof, finds the use of carbon nanotube production in a continuous batch process.

  In general, the term nanotechnology is used to denote an object with a size of 1.0 to 100.0 nm. Since nanotechnology theory was proposed over 40 years ago, nanotechnology has become one of the fastest developing scientific fields.

  Batch production of nanostructures is essential for the incorporation of nanostructures into everyday goods. Recently, numerous nanostructure batch production methods and devices have been reported. Most of these methods use plasma or a very hot furnace to generate atomic carbon vapor, which is then condensed onto a suitable substrate. This forms an array of carbon nanostructures, including nanotubes. When the atomic metal is supplied during production, single-walled nanotubes are mainly produced, and when the atomic metal is not supplied, multi-walled carbon nanotubes are usually produced.

  Particles of various sizes are generated along with the nanotubes. Some of these particles are always atomic carbon and their clusters, which are the focus of controversy due to their unknown impact on the environment or human health, and thus I'm impressed with the release into the atmosphere. It is currently believed that such particles can easily be absorbed or inhaled through the skin, form cancer, and / or harm major organs such as the heart and lungs.

  In a first aspect, the present invention provides a method for producing a nanostructure, the method comprising transporting a gas containing components of the nanostructure to a housing to form a gas stream within the housing; Conveying the contained gas into the housing; generating nanostructures from the components contained in the gas stream within the housing; separating the generated nanostructures from the gas stream for subsequent collection Removing the by-product from the gas stream by reacting the by-product of nanostructure formation with an oxygen-containing gas; and evacuating the gas stream from the housing.

  Thus, the above method provides a new realization technology for mass production of nanostructures such as carbon nanotubes in a simple and environmentally safe manner, and can utilize a low cost power source and vacuum components. The aspects of the production process can be performed in a single and small housing, thereby limiting the user's exposure to potentially dangerous by-products such as carbon nanoparticles.

  Nanostructures are preferably produced in each hollow cathode reactor and by-products are preferably removed from the gas stream in each hollow cathode reactor. Accordingly, in a second aspect, the present invention provides a method for producing a nanostructure, the method comprising passing a gas comprising a nanostructure component through a first hollow cathode reactor to pass the nanostructure. Generating, separating the nanostructures from the gas exhaust from the first hollow cathode reactor for collection, followed by a second hollow cathode reactor with the exhaust gas together with the oxygen-containing gas. Removing the byproduct of nanostructure formation from the exhaust gas by passing through.

  The hollow cathode reactor should be powered by a low cost power source. Hollow cathode reactors are typically small in size and operate safely at low frequencies. The gas temperature obtained in the hollow cathode reactor is suitable for the gas reaction generated during the production of the nanostructure and the removal of carbon nanoparticles from the exhaust gas.

  Various choices of both the hollow cathode material and process gas in this method give the user of the apparatus the advantage of generating an array of different types and qualities of carbon nanostructures.

  The first hollow cathode reactor preferably consists of holes arranged in parallel to the solid conductive body formed from one of aluminum, copper, stainless steel, tungsten, graphite, and passes through the holes. A plasma is formed in the hole by the generated gas.

  The metal-containing gas is passed through the first hollow cathode reactor to produce metal nanostructures, and the metals contained in the gas are preferably Fe, Ni, Mo, Co, Pt, Pd. Metal nanostructures provide a surface on which carbon nanostructures can be grown. The metal-containing gas is passed through a first hollow cathode reactor with an electronically excitable gas such as argon, helium, nitrogen, the electronically excitable gas initiates the formation of metal nanostructures and Can be increased.

  As a modified example or an additional example, for example, a carbon-containing gas containing at least one of acetylene, methane, ethane, carbon monoxide, carbon dioxide, methanol, ethanol, tetrafluoromethane, and hexafluoroethane is used as a carbon nanostructure. It may be passed through a first hollow cathode reactor to produce. The carbon-containing gas is advantageously passed through a first hollow cathode reactor together with at least one of electronically excitable gases such as argon, helium, nitrogen.

  Nanostructures are preferably produced using a plurality of first hollow cathode reactors.

  The nanostructures may be separated from the gas using a single electrostatic precipitator or array of electrostatic precipitators, either at the same voltage or different voltages, and advantageously all or various Allows collection of nanostructures of size. Preferably, the voltage between the array of electrostatic precipitators increases in the direction of gas flow through the array.

  The nanostructures may also be separated from the gas by collection on the substrate. The substrate may be cooled to a temperature below room temperature, for example using liquid nitrogen, or in the presence of at least one oxygen-containing gas, for example oxygen, air, ethanol, methanol, hydrogen peroxide, ozone. It may be heated above room temperature. This advantageously removes unwanted reaction byproducts, which are also separated from the gas from the production of the nanostructures.

  The use of the substrate advantageously allows the removal of the nanostructures collected thereby, for example by isolating the substrate using a load lock.

  The second hollow cathode reactor is preferably a parallel array of holes provided in the solid conductive body, preferably made of the same material as the first hollow cathode reactor, and the gas passed through the holes. A plasma is formed in the hole. An oxygen-containing gas, such as oxygen, air, ethanol, methanol, hydrogen peroxide, ozone, is preferably an electronically excitable gas such as one of argon, nitrogen, helium, preferably the second hollow cathode reaction. Supplied to the device.

  In a third aspect, the present invention provides an apparatus for generating a nanostructure, the apparatus comprising means for forming a gas flow within a housing for receiving a gas comprising a component of the nanostructure. , And means for receiving the oxygen-containing gas, the housing comprising means for forming the nanostructures from components contained within the gas stream and subsequent collection of the formed nanostructures. Means for separating from the gas stream for the purpose and means for removing the by-product of nanostructure formation from the gas stream by reacting the by-product with the oxygen-containing gas, the housing exhausting the gas stream Means for further comprising:

  In a fourth aspect, the present invention provides an apparatus for producing a nanostructure, the apparatus comprising a first hollow cathode reactor and a component of the nanostructure to form the nanostructure. Means for supplying gas to the first hollow cathode reactor, means for separating the nanostructures from the exhaust gas from the first hollow cathode reactor for collection, and subsequently receiving the exhaust gas And a means for supplying an oxygen-containing gas to the second hollow cathode reactor for removal of by-products of nanostructure formation from the exhaust gas.

  Features described above with respect to the method form of the present invention are equally applicable to the apparatus form, and vice versa.

  Preferred features of the present invention will now be described by way of example with reference to the accompanying drawings.

  FIG. 1 schematically illustrates a nanostructure generator. The device comprises a housing or body 2 which comprises a first device 8 for the formation of nanostructures and a second for the collection of nanostructures formed by the first device 8. An apparatus 10 and a third apparatus 12 for removing reaction byproducts from the production of nanostructures from the gas stream before the gas stream is evacuated from the body 2 are arranged. The body 2 includes inlets 4, 14 for receiving gas for use in producing nanostructures and an inlet 16 for receiving gas for use in removing byproducts from the gas stream. Inlets 4 and 14 may also be used to receive gas for use in removing by-products from the gas stream. The main body 2 also includes an exhaust port 6 for exhausting the exhaust gas from the main body toward the mechanical vacuum pump.

  Various embodiments of the first apparatus 8a, 8b, 8c for the production of nanostructures are shown in detail in FIGS. 2, 3 and 4, respectively.

  In the first embodiment shown in FIG. 2, the main body 2 comprises a substantially cylindrical main body, which is arranged substantially coaxially with the main body for receiving a gas forming a gas flow in the main body 2. And a first generator gas inlet 4. The first device 8 a includes a non-conductive inner shell 20 disposed in the main body 2. The inner shell 20 supports a substantially cylindrical conductive block 22. A plurality of axially oriented holes are formed in the block 22. The inner shell 20 also supports a substantially ring-shaped anode 24. A number of perforated anode tips 26 extend from the anode 24 toward the outer periphery of the substantially flat surface of the block 22. Such an anode tip 26 can help maintain a plasma and hollow cathode effect in each of the holes in the block 22.

  A power supply 28 is provided to charge the block 22 to a cathode (negative) potential and to charge the anode 24 to an anode (positive) potential. The gas outlet from the first device 8a is shown at 40 in FIG. 2, and the gas flow exhaust from the first device 8a is carried from the gas outlet 40 to the second device 10.

  During use of the first apparatus 8a shown in FIG. 2, the vapor of the metal-containing compound, for example, at least one vapor of metallocene, metal sponge, organometallic compound and metal halide, is generated by the first generator gas inlet 4 and the anode. 24, the metal-containing compound is dissociated into atomic metal in the plasma (ionized state) in the block 22 continuously or periodically. The metal-containing vapor may be carried to the first generator gas inlet 4 together with or separately from at least one of electronically excitable gases such as nitrogen, argon and helium.

  At least one of a carbon-containing gas, such as acetylene, methane, ethane, carbon monoxide, carbon dioxide, methanol, ethanol, tetrafluoromethane, and hexafluoroethane, simultaneously or separately with the metal-containing vapor and the electronically excitable gas. The gas is dissociated into atomic carbon and its clusters in the plasma in the block 22 by being conveyed continuously or periodically through the first generator inlet 4 and the anode 24 to the block 22. Atomic metal and atomic carbon combine to align other carbon nanostructures in the gas stream downstream from block 22 within the holes of block 22 and on the surface of second device 10 for collection of nanostructures 12. Along with promoting the production of single-walled nanotubes.

  An oxygen-containing gas, such as oxygen, air, ethanol, methanol, hydrogen peroxide, water and ozone, may optionally be carried to block 22 via first device inlet 4 and anode 24, The gas is dissociated into oxygen radicals. The oxygen radicals generated in the block 22 react with the carbon nanoparticles generated in the first device 8a and any carbon nanoparticles generated in the second device 10 to react with the carbon nanoparticles from the device 2. Can be removed.

  A first device 8b of the second embodiment is shown in FIG. In this second embodiment, the main body 2 has a first generator gas inlet 4 arranged substantially coaxially with the main body 2 and a second generation for carrying the gas substantially radially into the main body. It consists of a substantially cylindrical body with a device gas inlet 14. Inner shell 20 supports two spaced, generally cylindrical conductive blocks 22 and 34. As in the block 22 of the first embodiment, the blocks 22 and 34 are formed with a plurality of axially oriented holes. An annular insulating element 32 is disposed between the blocks 22, 34 to provide further insulation between the blocks 22, 34. As shown in FIG. 3, the blocks 22, 34 are disposed on both sides of the second generator gas inlet 14.

  As in the first embodiment, the inner shell 20 supports a substantially ring-shaped anode 24. The plurality of perforated anode tips 26 extend from the anode 24 toward the outer periphery of the substantially flat surface of the block 22. Such an anode tip 26 can help maintain the plasma and hollow cathode effects of each of the holes in the blocks 22, 34. The gas outlet from the first device 8b is shown at 40 in FIG. 3, and the gas flow exhaust from the first device 8b is carried from the gas outlet 40 to the second device 10.

  A power supply 28 is provided to charge the block 22 to a cathode (negative) potential and to charge the anode 24 to an anode (positive) potential. A similar power supply 29 is provided to charge the block 34 to the cathode (negative) potential and the anode 24 to the anode (positive) potential.

  During use of the first apparatus 8b shown in FIG. 3, the vapor of the metal-containing compound continues to the blocks 22 and 34 via the first generator gas inlet 4 and the anode 24 as in the first embodiment or Carried periodically, in blocks 22 and 34, metal-containing compounds are dissociated into atomic metals in the plasma. The vapor may be carried to the first generator gas inlet 4 together with or separately from the electronically excitable gas.

  Concurrently or separately with the metal-containing vapor and the electronically excitable gas, the carbon-containing gas is carried continuously or periodically through the second generator gas inlet 14 to the block 34, where it is within the block 34. The gas is dissociated into atomic carbon and its clusters in the plasma. The atomic metal and atomic carbon then combine to promote the production of single-walled nanotubes along with other carbon nanostructure arrays in the gas stream downstream from the metal block and within the holes in blocks 22,34. can do.

  An oxygen-containing gas may optionally be conveyed to the blocks 22, 34 via the first generator inlet 4 and the anode 24 and to the block 34 via the second generator gas inlet 14, in the blocks 22, 34. The gas is dissociated into oxygen radicals. The oxygen radicals generated therein are combined with the carbon nanoparticles produced by the first device 8b and any carbon nanoparticles produced by the second device 10 in order to remove the carbon nanoparticles from the device 2. Can react.

  A first device 8c of the third embodiment is shown in FIG. In this third embodiment, the body 2 of the first device 8c includes two generally orthogonal, connected cylindrical arms 3,5. The first generator gas inlet 4 is arranged substantially coaxially with the first arm 3. The first arm 3 includes a non-conductive inner shell 20 and supports a substantially cylindrical conductive block 22. A plurality of axially oriented holes are formed in the block 22. The inner shell 20 also supports a substantially ring-shaped anode 24. A plurality of perforated anode tips 26 extend from the anode 24 toward the outer periphery of the substantially flat surface of the block 22.

  The second arm 5 includes a second generator gas inlet 14 disposed substantially coaxially with the second arm 5. The second arm 5 also includes a part of the non-conductive inner shell 20 and supports a substantially cylindrical conductive block 35. A plurality of axially oriented holes are formed in the block 35. The inner shell 20 also supports a substantially ring-shaped anode 25 in the second arm 5. The plurality of perforated anode tips 27 extend from the anode 25 toward the outer periphery of the substantially flat surface of the block 35. The gas outlet from the first device 8c is shown at 40 in FIG.

  A power supply 28 is provided to charge the block 22 to a cathode (negative) potential and to charge the anode 24 to an anode (positive) potential. A similar power supply 29 is provided to charge the block 35 to a cathode (negative) potential and to charge the anode 25 to an anode (positive) potential.

  In use, the vapor of the metal-containing compound is carried continuously or periodically to the block 22 via the first generator gas inlet 4 and the anode 24, in which the metal-containing compound is an atomic metal in the plasma. Is dissociated. The metal-containing vapor may be delivered to the first generator gas inlet 4 together with or separately from the electronically excitable gas. Simultaneously or separately from the metal-containing vapor and the electronically excitable gas, the carbon-containing gas is carried to block 35 continuously or periodically via the second generator gas inlet 14 and the anode 25, In block 35, the gas is dissociated into electronic carbon and its clusters in the plasma. The atomic metal and atomic carbon are then combined together with an array of other carbon nanostructures in the gas stream, downstream from the metal block, so that single-walled nanotubes are in the holes of blocks 22, 35, And facilitates the generation of carbon on the surface of the second device 10 for the collection of nanostructures so formed.

  As described above with respect to the first device 8a of the first embodiment and the first device 8b of the second embodiment, the oxygen-containing gas also passes through the first generator inlet 4 and the anode 24 to block 22. , 34 and via the second generator gas inlet 14 and the anode 25 may be carried to block 35 and in blocks 22, 34, 35 the oxygen radicals for reaction with the carbon nanoparticles. Is dissociated.

  In each of the embodiments described above, the gas stream output from the first device 8 is conveyed to the second device 10 within the body 2 for collection of the nanostructures contained therein. Two embodiments 10a, 10b of the second device 10 will now be described in more detail with reference to FIGS. 5 and 6, respectively.

  In the first embodiment shown in FIG. 5, the second device 10a receives a gas flow from the first device 8 that includes nanostructures and by-products from the production of nanostructures such as smaller nanoparticles. Including a first nanostructure collector gas inlet 60. The second device 10 a includes a non-conductive inner shell 50 disposed in the main body 2. The inner shell 50 supports the first electric dust collector 52. As is known, the electrostatic precipitator 52 is comprised of a plurality of parallel spaced, high voltage charged, generally rectangular collector plates 54 and ground plates 56 supported in an alternating sequence by suitable transverse support rods. And the insulator and the spacer, each plate in order has a polarity opposite to that of the immediately adjacent plate, and forms the collecting portion of the electrostatic precipitator 52. Also, as is known, the ionization wire 58 and the extended ground plate 56a are positioned proximate to the first collector gas inlet 60 to produce a corona current that extends toward the extended ground plate 56a. Thereby forming the ionized portion of the high concentration ion curtain. The gas outlet from the inner shell 50 is shown at 65 in FIG.

  In use, as the gas stream enters the device 10a through the first nanostructure collector gas inlet 60, the nanostructures incorporated therein are charged as they pass into the high concentration ion curtain, And separated from the gas flow by the attractive force to the surface of the collector plate 54, the collector plate forms a substrate that can be removed from the device 2 for the collection of nanostructures disposed on the substrate. Smaller nanoparticles contained in the gas stream are not collected on the collector plate 54 and thus pass through the device 10a.

  In the second embodiment shown in FIG. 6, the second device 10b is a first nanostructure collector gas inlet for receiving a gas stream comprising nanostructures and nanoparticle byproducts from the first device 8. 60. As in the first embodiment, the second device 10 b includes a non-conductive inner shell 50 disposed within the body 2. In this second embodiment, the inner shell 50 supports an array of substantially equal electrostatic precipitators 52 ', each similar to the electrostatic precipitator 52 of the first embodiment. In the second embodiment, each collector plate 54 of the electrostatic precipitator 52 'is preferably set to an increased voltage relative to the previous electrostatic precipitator in the direction of gas flow. By generating a voltage that increases in the direction of gas flow through the second device 10b, it is possible to separate different sized nanostructures in the corresponding collector plate 54, with smaller nanostructures downstream. It is drawn to the collector plate 54. In the illustrated embodiment, three electrostatic precipitators 52 'are shown, but it is possible to use more or less than three electrostatic precipitators. The gas outlet from the inner shell 50 is shown at 65 in FIG.

  In any of the above embodiments of the second device 10, the collector plate 54 is cooled using, for example, liquid nitrogen carried around the device 10 to facilitate separation of the nanostructures from the gas stream. It is good. Depending on the composition of the nanostructures, as an alternative, separation of the nanostructures from the gas stream may be facilitated, for example, by heating the collector plate 54 with a heater that extends around the device 10. A load lock device (not shown) may also be provided to isolate the collector plate 54 and the nanostructures collected on the collector plate from the gas flow. This allows the user to remove the collected nanostructures and reduce the risk of exposure to potentially harmful nanoparticles without having to open the vacuum seal.

  In each of the above-described embodiments, the gas stream output from the second device 10 is transferred to the third device 12 within the body 2 to remove any nanoparticle by-products contained therein from the gas stream. Carried. Two embodiments 12a, 12b of the third device 12 will now be described in detail with reference to FIGS.

  In the first embodiment shown in FIG. 7, the third device 12a includes a first removal device gas inlet 90 for receiving a gas flow from the second device 10, a second removal device gas inlet 16, and , And the oxygen-containing gas enters substantially radially from the gas inlet 16 into the body 2. Examples of suitable oxygen-containing gases include one or more of oxygen, air, ethanol, methanol, hydrogen peroxide, water and ozone.

  Similar to the embodiment of the first device 8 described above, in this embodiment, the third device 12 a includes a non-conductive inner shell 70 disposed within the body 2. The inner shell 70 supports a substantially cylindrical conductive block 76. The block 76 has a plurality of axially oriented holes. The inner shell 70 also supports a substantially ring-shaped anode 80. The plurality of porous anode tips 82 extend from the anode 80 toward the outer periphery of the substantially flat surface of the block 76. Such an anode tip 82 can help maintain a plasma and hollow cathode effect within each of the holes in the block 76. A power supply 78 is provided to charge the block 76 to a cathode (negative) potential and the anode 80 to an anode (positive) potential.

  In use, a gas stream containing by-products is conveyed through inlet 90 to metal block 76 of third device 12a. The oxygen-containing gas that enters the device 12a through the inlet 16 mixes with a gas stream containing by-products from nanostructure formation. The mixed gas stream is dissociated in the plasma formed in block 76 so that by-products react with oxygen radicals to produce an array of oxidized forms of carbon, such as carbon dioxide and carbon monoxide. Then, the gas is discharged from the main body 2 through the gas outlet 6 to the mechanical vacuum pump together with the gas flow.

  The second embodiment shown in FIG. 8 is similar to the first embodiment. In this second embodiment, the inner shell 70 supports two spaced apart, generally cylindrical conductive blocks 74 and 76. As in the first embodiment, the metal blocks 74 and 76 are formed with a plurality of axially oriented holes. An annular insulating element 72 is disposed between the metal blocks 74, 76 to provide further insulation between the metal blocks 74, 76. As shown in FIG. 8, the metal blocks 74, 76 are disposed on both sides of the second removal device gas inlet 16. A power supply 78 is provided to charge the block 74 to a cathode (negative) potential and the anode 80 to an anode (positive) potential. A similar power supply 78a is provided to charge the block 76 to a cathode (negative) potential and the anode 80 to an anode (positive) potential.

  The embodiments of the first device 8, the second device 10 and the third device 12 described above may be used in any combination of the devices 2. For example, in one preferred embodiment of the device 2, the first device 8 is as shown in FIG. 3, the second device 10 is as shown in FIG. The third device 12 is as shown in FIG.

  In any combination of the first device 8, the second device 10 and the third device 12 described above, the non-conductive inner shell 20, 50, 70 can be either a separate shell or a continuous shell throughout the device 2. It may be.

It is a figure which shows the general outline of the production | generation apparatus of a nanostructure. 1 shows a first embodiment of an apparatus for generating nanostructures. FIG. FIG. 3 shows a second embodiment of an apparatus for generating nanostructures. FIG. 4 shows a third embodiment of an apparatus for generating nanostructures. FIG. 1 shows a first embodiment of an apparatus for collecting nanostructures. FIG. 3 shows a second embodiment of an apparatus for collecting nanostructures. FIG. 3 shows a first embodiment of an apparatus for removing by-products from nanostructure production from a gas. FIG. 3 shows a second embodiment of an apparatus for removing by-products from nanostructure production from a gas.

Explanation of symbols

2 Main body 4, 14, 16 Inlet 6 Exhaust port 8 First device 10 Second device 12 Third device

Claims (37)

A method for producing a nanostructure comprising:
Conveying a gas comprising nanostructure components to the housing to form a gas flow within the housing;
Carrying an oxygen-containing gas into the housing;
In the housing,
Generating nanostructures from components contained in the gas stream;
Separating the produced nanostructures from the gas stream for subsequent collection;
Removing the by-product of nanostructure formation from the gas stream by reacting the by-product with an oxygen-containing gas;
And the stage of
Exhausting the gas stream from the housing;
Including the above method.   The method of claim 1, wherein the nanostructure is produced in a first hollow cathode reactor.   The method of claim 2, wherein the by-product is removed from the gas stream using a second hollow cathode reactor. A method for producing a nanostructure comprising:
Passing a gas containing the components of the nanostructure through a first hollow cathode reactor to produce the nanostructure;
Separating the nanostructures from the gas exhaust from the first hollow cathode reactor for collection;
Subsequently removing the by-product of nanostructure formation from the exhaust gas by passing the exhaust gas along with an oxygen-containing gas through a second hollow cathode reactor;
Including the above method.   5. The first hollow cathode reaction device comprises parallel-arranged holes provided in a solid conductive body, and a plasma is formed in the holes by a gas passed through the holes. The method described in 1.   6. The method of claim 5, wherein the body is formed from one of aluminum, copper, stainless steel, tungsten, graphite.   7. A method according to any of claims 2 to 6, wherein a metal-containing gas is passed through the first hollow cathode reactor to produce metal nanostructures.   The method according to claim 7, wherein the metal comprises at least one of Fe, Ni, Mo, Co, Pt, and Pd.   9. A process according to claim 7 or 8, wherein the metal-containing gas is passed through a first hollow cathode reactor together with an electronically excitable gas.   The method of claim 9, wherein the electronically excitable gas comprises at least one of argon, helium, and nitrogen.   11. A method according to any one of claims 2 to 10, wherein a carbon-containing gas is passed through the first hollow cathode reactor to produce carbon nanostructures.   The method according to claim 11, wherein the carbon-containing gas comprises at least one of acetylene, methane, ethane, carbon monoxide, carbon dioxide, methanol, ethanol, tetrafluoromethane, and hexafluoroethane.   13. A process according to claim 11 or 12, wherein the carbon-containing gas is passed through a first hollow cathode reactor together with an electronically excitable gas.   The method of claim 13, wherein the electronically excitable gas comprises at least one of argon, helium, and nitrogen.   15. A method according to any one of claims 2 to 14, wherein the nanostructure is generated using a plurality of first hollow cathode devices.   The method according to claim 1, wherein the nanostructure is separated from the gas using an electrostatic precipitator.   The method of claim 16, wherein the nanostructures are separated from the gas using an array of electrostatic precipitators.   The method of claim 17, wherein the electrostatic precipitator is at the same voltage.   The method of claim 17, wherein the electrostatic precipitator is at a different voltage.   20. The method of claim 19, wherein the voltage across the array of electrostatic precipitators increases in the direction of gas flow through the array.   21. A method according to any preceding claim, wherein the nanostructures are separated from the gas by collection on a substrate.   The method of claim 21, wherein the substrate is cooled to a temperature below room temperature.   23. The method of claim 22, wherein the substrate is cooled using liquid nitrogen.   The method of claim 21, wherein the substrate is heated to a temperature above room temperature.   The method of claim 24, wherein the substrate is heated in the presence of an oxygen-containing gas.   26. A method according to claim 24 or claim 25, wherein the substrate is heated in the presence of at least one of oxygen, air, ethanol, methanol, hydrogen peroxide, ozone.   27. A method according to any of claims 21 to 26, wherein the substrate is isolated from the gas for removal of the collected nanostructures.   28. The method of claim 27, wherein the substrate is isolated using a load lock.   29. The second hollow cathode reactor is a parallel array of holes provided in a solid conductive body, and a plasma is formed in the holes with the gas passed through the holes. The method described in 1.   30. The method of claim 29, wherein the solid conductive body is formed from one of aluminum, copper, graphite, stainless steel, tungsten.   The method according to any one of claims 1 to 30, wherein the oxygen-containing gas comprises at least one of oxygen, air, ethanol, methanol, hydrogen peroxide, and ozone.   32. A method according to any preceding claim, wherein the oxygen-containing gas is supplied with an electronically excitable gas.   The method of claim 32, wherein the electronically excitable gas comprises one of argon, nitrogen, and helium. An apparatus for manufacturing a nanostructure,
A housing comprising means for receiving a gas comprising a component of the nanostructure to form a gas flow within the housing, and means for receiving an oxygen-containing gas;
The housing includes means for generating nanostructures from components contained within the gas stream, means for separating the nanostructures generated for subsequent collection from the gas stream, and oxygen containing byproducts. Means for removing by-products of nanostructure formation from the gas stream by reacting with the gas, and
The apparatus as described above, wherein the housing further comprises means for exhausting the gas stream.   35. The apparatus of claim 34, wherein the nanostructure generating means comprises a hollow cathode reaction apparatus.   36. The apparatus according to claim 34 or claim 35, wherein the by-product removing means comprises a hollow cathode reaction apparatus. An apparatus for manufacturing a nanostructure,
A first hollow cathode reactor;
Means for supplying a gas comprising a component of the nanostructure to the first hollow cathode reactor to produce the nanostructure;
Means for separating the nanostructures from the gas exhaust from the first hollow cathode reactor for collection;
A second hollow cathode reactor for subsequently receiving exhaust gas;
Means for supplying an oxygen-containing gas to the second hollow cathode reactor for removal of nanostructured by-products from the exhaust gas;
Including the above device.

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