JP2682486B2 - Method for purifying carbon nanotubes - Google Patents

Method for purifying carbon nanotubes

Info

Publication number
JP2682486B2
JP2682486B2 JP7005873A JP587395A JP2682486B2 JP 2682486 B2 JP2682486 B2 JP 2682486B2 JP 7005873 A JP7005873 A JP 7005873A JP 587395 A JP587395 A JP 587395A JP 2682486 B2 JP2682486 B2 JP 2682486B2
Authority
JP
Japan
Prior art keywords
carbon
metal
carbon nanotubes
metal catalyst
impurities
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
JP7005873A
Other languages
Japanese (ja)
Other versions
JPH08198611A (en
Inventor
鋭也 市橋
澄男 飯島
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NEC Corp
Original Assignee
NEC Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by NEC Corp filed Critical NEC Corp
Priority to JP7005873A priority Critical patent/JP2682486B2/en
Publication of JPH08198611A publication Critical patent/JPH08198611A/en
Application granted granted Critical
Publication of JP2682486B2 publication Critical patent/JP2682486B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【0001】[0001]

【産業上の利用分野】本発明は、カーボンナノチューブ
の精製方法、とりわけ金属触媒を用いて製造されたカー
ボンナノチューブの精製方法に関する。
TECHNICAL FIELD The present invention relates to a method for purifying carbon nanotubes, and more particularly to a method for purifying carbon nanotubes produced using a metal catalyst.

【0002】[0002]

【従来の技術】数個以上の円筒状黒鉛層が同心円状に形
成された通常のカーボンナノチューブは、円筒の大きさ
が一定でなく、従ってカーボンナノチューブの電気特性
や化学特性には大きなばらつきがあった。そこで、チュ
ーブの形状が単層に制御された単原子層カーボンナノチ
ューブの製造方法を、本発明者等は特願平5−3379
37号出願明細書にて提案した。この単原子層カーボン
ナノチューブは、放電電極の一方に炭素を、他方の電極
に金属(鉄、コバルト、ニッケルなどの遷移金属)と炭
素の混合物を用い、原料ガスに炭化水素を用いてアーク
放電により製造される。
2. Description of the Related Art In a conventional carbon nanotube in which several or more cylindrical graphite layers are concentrically formed, the size of the cylinder is not constant, and therefore the electrical and chemical properties of the carbon nanotube vary widely. It was Therefore, the inventors of the present invention have disclosed a method for producing a single-atom-wall carbon nanotube in which the shape of the tube is controlled to be a single layer, by the inventors of the present invention.
No. 37 application specification. This single-atom-wall carbon nanotube uses carbon for one of the discharge electrodes, a mixture of metal (transition metal such as iron, cobalt, and nickel) and carbon for the other electrode, and a hydrocarbon as a source gas for arc discharge. Manufactured.

【0003】[0003]

【発明が解決しようとする課題】しかし、上記の方法に
より得られる単原子層カーボンナノチューブは、金属触
媒を用いて製造されるため、金属触媒とその炭化物及び
非晶質炭素、グラファイト等のカーボンナノチューブ以
外の炭素物質を不純物として含んでいた。従って、この
カーボンナノチューブを産業上利用するためには上記不
純物を取り除く必要があり、カーボンナノチューブの有
する電気特性や化学特性の点を考えると、特に上記不純
物の中でも金属触媒とその金属の炭化物を取り除く必要
がある。しかし、従来技術に、カーボンナノチューブ以
外の炭素物質を、浮選や遠心分離により除去する方法は
特開平6−228824号公報に示されているが、未精
製カーボンナノチューブから金属触媒とその金属の炭化
物などの金属不純物を取り除く方法はこれまで存在しな
かった。
However, since the monoatomic layer carbon nanotube obtained by the above method is produced using a metal catalyst, the metal catalyst and its carbide and carbon nanotubes such as amorphous carbon and graphite are used. Other carbon substances were included as impurities. Therefore, in order to industrially utilize the carbon nanotubes, it is necessary to remove the above impurities. Considering the electric characteristics and chemical characteristics of the carbon nanotubes, in particular, among the above impurities, the metal catalyst and the carbide of the metal are removed. There is a need. However, in the prior art, a method of removing carbon substances other than carbon nanotubes by flotation or centrifugation is disclosed in Japanese Patent Laid-Open No. 6-228824. Until now, there has been no method for removing metal impurities such as.

【0004】本発明の目的は、金属触媒を用いて製造さ
れたカーボンナノチューブから、特に金属触媒とその炭
化物を、さらにはカーボンナノチューブ以外の炭素物質
をも除去することにある。
It is an object of the present invention to remove, in particular, a metal catalyst and its carbide, and also carbon substances other than carbon nanotubes from carbon nanotubes produced using a metal catalyst.

【0005】[0005]

【課題を解決するための手段】上記課題を解決するた
め、本発明の第1の発明は、金属触媒を用いて製造され
た金属触媒とその金属の炭化物を不純物として含む未精
製カーボンナノチューブに、酸を加えることにより、前
記不純物を溶解することを特徴とするカーボンナノチュ
ーブの精製方法である。
In order to solve the above-mentioned problems, the first invention of the present invention provides a metal catalyst produced by using a metal catalyst and an unpurified carbon nanotube containing a carbide of the metal as an impurity, A method for purifying carbon nanotubes, characterized in that the impurities are dissolved by adding an acid.

【0006】第2の発明は、金属触媒を用いて製造され
た金属触媒とその金属の炭化物を不純物として含む未精
製カーボンナノチューブを、液体中に粉砕、分散し、前
記液体を磁場中を通過させることにより前記不純物を除
去することを特徴とするカーボンナノチューブの精製方
法である。
A second aspect of the invention is to pulverize and disperse a metal catalyst produced by using a metal catalyst and an unpurified carbon nanotube containing carbides of the metal as impurities, and pass the liquid through a magnetic field. Thus, the method for purifying carbon nanotubes is characterized in that the impurities are removed.

【0007】第3の発明は、金属触媒を用いて製造され
た金属触媒と金属の炭化物とカーボンナノチューブ以外
の炭素物質を不純物として含む未精製カーボンナノチュ
ーブを、液体中に粉砕、分散し、前記液体中に含まれる
前記炭素物質を遠心分離または浮選により除去し、炭素
物質を除去した後の液体に酸を加えて前記金属不純物を
溶解するか、あるいは炭素物質を除去した後の液体を磁
場中を通過させることにより前記金属不純物を除去する
ことを特徴とするカーボンナノチューブの精製方法であ
る。
A third aspect of the invention is to grind and disperse a metal catalyst produced by using a metal catalyst, a metal carbide, and an unpurified carbon nanotube containing carbon substances other than carbon nanotubes as impurities in a liquid to obtain the liquid. The carbon substance contained therein is removed by centrifugation or flotation, and the metal impurities are dissolved by adding an acid to the liquid after removing the carbon substance, or the liquid after removing the carbon substance is subjected to a magnetic field. The method for purifying carbon nanotubes is characterized in that the metal impurities are removed by passing the carbon nanotubes.

【0008】[0008]

【作用】本発明のカーボンナノチューブの精製方法は、
粗生成物を粉砕、攪拌し、遠心分離、浮選により非晶質
炭素、グラファイト等のカーボンナノチューブ以外の炭
素物質を除去し、さらに酸を加えて金属を溶かす、ある
いは磁場中を通過させることにより金属不純物を除去
し、カーボンナノチューブの純度を向上させるものであ
る。
The function of purifying carbon nanotubes of the present invention is as follows:
By crushing and stirring the crude product, removing carbon substances other than carbon nanotubes such as amorphous carbon and graphite by centrifugal separation and flotation, and further adding acid to dissolve the metal or pass through a magnetic field. It removes metal impurities and improves the purity of carbon nanotubes.

【0009】[0009]

【実施例】本発明の一実施例を以下に示す。An embodiment of the present invention will be described below.

【0010】(実施例1)精製に用いた単原子層カーボ
ンナノチューブの粗生成物は、放電電極の一方の電極
(正電極)に炭素棒を、他方の電極(負電極)に金属
(鉄、コバルト、ニッケル等の遷移金属)を含んだ炭素
棒を用い、メタン、水素、ヘリウムの混合ガス雰囲気中
でアーク放電により製造して得た。この時の負電極に
は、炭素棒に穴を開け金属線(鉄線など)を挿入したも
のを使用し、これにより負電極として金属棒を用いた場
合には電極が溶けてしまうような温度でも使用可能で、
挿入する金属線の本数により、炭素棒表面に露出する炭
素と金属の面積比を制御できるため、金属の蒸発量を制
御できる。本実施例では、鉄線が挿入された炭素棒を負
電極として用い、メタンガス20Torr、ヘリウムガ
ス180Torr、水素ガス10Torrの雰囲気で、
放電電圧30V、放電電流50Aでアーク放電させるこ
とにより、太さが1〜2nmで揃った大量の単層カーボン
ナノチューブを得た。
(Example 1) The crude product of the single-atom-walled carbon nanotubes used for purification was a carbon rod on one electrode (positive electrode) of the discharge electrode, and a metal (iron, on the other electrode (negative electrode)). A carbon rod containing (transition metal such as cobalt and nickel) was used to obtain by arc discharge in a mixed gas atmosphere of methane, hydrogen and helium. The negative electrode used at this time is a carbon rod in which a metal wire (iron wire, etc.) has been inserted and a metal wire (iron wire, etc.) has been inserted, so that even if the metal rod is used as the negative electrode, the temperature will melt Available,
Since the area ratio of carbon and metal exposed on the surface of the carbon rod can be controlled by the number of metal wires to be inserted, the evaporation amount of metal can be controlled. In this embodiment, a carbon rod having an iron wire inserted therein is used as a negative electrode, and the atmosphere is 20 Torr of methane gas, 180 Torr of helium gas, and 10 Torr of hydrogen gas.
By performing arc discharge at a discharge voltage of 30 V and a discharge current of 50 A, a large amount of single-walled carbon nanotubes having a uniform thickness of 1 to 2 nm was obtained.

【0011】上記方法により得られた単層カーボンナノ
チューブ粗生成物は、製造時に使用した金属触媒とその
金属の炭化物、および非晶質炭素やグラファイト等のカ
ーボンナノチューブ以外の炭素物質を不純物として含ん
でいる。そこで、上記方法により得られた粗生成物を、
スチールボールとエタノールを入れた容器に入れ、加振
器(たとえば超音波をかける)で粉砕し、液中に攪拌し
た。この溶液を遠心分離器にかけ、上澄みを取り除くこ
とにより、非晶質炭素、グラファイト等の微小な球状粒
子を取り除いた。さらに、この上澄みを取り除いた試料
に硝酸を加えることにより鉄を溶かし、単原子層カーボ
ンナノチューブの精製を行った。これにより、金属触媒
を用いて製造されたカーボンナノチューブから、金属触
媒とその炭化物を、さらにはカーボンナノチューブ以外
の炭素物質をも除去することができた。酸としては、硝
酸の他に塩酸なども使用でき、酸を加えて加温する方が
好ましい。この際の温度は、酸が沸騰しない温度(約1
00℃)以下であればよい。
The single-walled carbon nanotube crude product obtained by the above method contains, as impurities, the metal catalyst used at the time of production, the carbide of the metal, and carbon substances other than carbon nanotubes such as amorphous carbon and graphite. There is. Therefore, the crude product obtained by the above method,
It was placed in a container containing a steel ball and ethanol, pulverized with a shaker (for example, ultrasonic waves were applied), and stirred in the liquid. The solution was put into a centrifuge and the supernatant was removed to remove fine spherical particles such as amorphous carbon and graphite. Further, nitric acid was added to the sample from which the supernatant had been removed to dissolve iron to purify the single-atom-wall carbon nanotubes. As a result, it was possible to remove the metal catalyst and its carbide, as well as carbon substances other than carbon nanotubes from the carbon nanotubes produced using the metal catalyst. As the acid, hydrochloric acid or the like can be used in addition to nitric acid, and it is preferable to add acid and heat. The temperature at this time is a temperature at which the acid does not boil (about 1
The temperature may be not higher than 00 ° C.

【0012】(実施例2)上澄みを取り除くまでは実施
例1と同じ精製を行った。その後、本実施例では、上澄
みを取り除いた溶液を磁場中を通過させることにより、
鉄を除去し、単原子層カーボンナノチューブの精製を行
った。本実施例の方法によっても、金属触媒を用いて製
造されたカーボンナノチューブから、金属触媒とその炭
化物、およびカーボンナノチューブ以外の炭素物質を除
去することができた。
Example 2 The same purification as in Example 1 was carried out until the supernatant was removed. Then, in this example, by passing the solution with the supernatant removed in a magnetic field,
The iron was removed and the single-atom-wall carbon nanotube was purified. Also by the method of this example, it was possible to remove the metal catalyst, its carbide, and the carbon substance other than the carbon nanotube from the carbon nanotube produced using the metal catalyst.

【0013】[0013]

【発明の効果】本発明によれば、金属触媒を用いて製造
されたカーボンナノチューブ中の、金属触媒やその炭化
物を、さらには非晶質炭素、グラファイト等の炭素物質
をも除去することができる。これにより、チューブの形
状が単層に制御され、かつ純度の高いカーボンナノチュ
ーブが得られる。
EFFECTS OF THE INVENTION According to the present invention, it is possible to remove metal catalysts and their carbides, as well as carbon substances such as amorphous carbon and graphite, from carbon nanotubes produced using metal catalysts. . Thereby, the shape of the tube is controlled to be a single layer, and carbon nanotubes with high purity can be obtained.

Claims (3)

(57)【特許請求の範囲】(57) [Claims] 【請求項1】金属触媒を用いて製造された前記金属触媒
と前記金属の炭化物を不純物として含む未精製カーボン
ナノチューブに、酸を加えることにより、前記不純物を
溶解することを特徴とするカーボンナノチューブの精製
方法。
1. A carbon nanotube characterized in that an impurity is dissolved by adding an acid to an unpurified carbon nanotube containing the metal catalyst and a carbide of the metal produced as an impurity by using a metal catalyst. Purification method.
【請求項2】金属触媒を用いて製造された前記金属触媒
と前記金属の炭化物を不純物として含む未精製カーボン
ナノチューブを、液体中に粉砕、分散し、前記液体を磁
場中を通過させることにより前記不純物を除去すること
を特徴とするカーボンナノチューブの精製方法。
2. The metal catalyst produced using a metal catalyst and the unpurified carbon nanotubes containing the carbide of the metal as impurities are pulverized and dispersed in a liquid, and the liquid is passed through a magnetic field to obtain the A method for purifying carbon nanotubes, which comprises removing impurities.
【請求項3】金属触媒を用いて製造された前記金属触媒
と前記金属の炭化物とカーボンナノチューブ以外の炭素
物質を不純物として含む未精製カーボンナノチューブ
を、液体中に粉砕、分散し、前記液体中に含まれる前記
炭素物質を遠心分離または浮選により除去し、 前記炭素物質を除去した後の液体に酸を加えて前記金属
不純物を溶解するか、あるいは前記炭素物質を除去した
後の液体を磁場中を通過させることにより前記金属不純
物を除去することを特徴とするカーボンナノチューブの
精製方法。
3. An unpurified carbon nanotube containing the metal catalyst produced by using a metal catalyst, a carbide of the metal, and a carbon substance other than the carbon nanotube as impurities, is pulverized and dispersed in a liquid, and is then added to the liquid. The contained carbon material is removed by centrifugation or flotation, and the liquid after removing the carbon material is added with an acid to dissolve the metal impurities, or the liquid after removing the carbon material is subjected to a magnetic field. A method for purifying carbon nanotubes, wherein the metal impurities are removed by passing the carbon nanotubes.
JP7005873A 1995-01-18 1995-01-18 Method for purifying carbon nanotubes Expired - Lifetime JP2682486B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP7005873A JP2682486B2 (en) 1995-01-18 1995-01-18 Method for purifying carbon nanotubes

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP7005873A JP2682486B2 (en) 1995-01-18 1995-01-18 Method for purifying carbon nanotubes

Publications (2)

Publication Number Publication Date
JPH08198611A JPH08198611A (en) 1996-08-06
JP2682486B2 true JP2682486B2 (en) 1997-11-26

Family

ID=11623050

Family Applications (1)

Application Number Title Priority Date Filing Date
JP7005873A Expired - Lifetime JP2682486B2 (en) 1995-01-18 1995-01-18 Method for purifying carbon nanotubes

Country Status (1)

Country Link
JP (1) JP2682486B2 (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010174419A (en) * 2009-01-30 2010-08-12 Showa Denko Kk Apparatus for removing iron-based impurities in vapor grown carbon fibers
JP2010174418A (en) * 2009-01-30 2010-08-12 Showa Denko Kk Method for removing iron-based impurities in vapor grown carbon fibers
US8449858B2 (en) 2009-06-10 2013-05-28 Carbon Solutions, Inc. Continuous extraction technique for the purification of carbon nanomaterials
US8454923B2 (en) 2009-06-10 2013-06-04 Carbon Solutions, Inc. Continuous extraction technique for the purification of carbon nanomaterials
KR20170041738A (en) * 2014-08-01 2017-04-17 광동 어글레이어 압토일렉트라닉 머티어리얼즈 컴퍼니 리미티드 Carbon nanotube-macromolecule composite layered transparent flexible electrode and preparation method therefor

Families Citing this family (31)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6683783B1 (en) 1997-03-07 2004-01-27 William Marsh Rice University Carbon fibers formed from single-wall carbon nanotubes
JP2002515847A (en) * 1997-05-29 2002-05-28 ウィリアム・マーシュ・ライス・ユニバーシティ Carbon fibers formed from single-walled carbon nanotubes
KR100364095B1 (en) * 1999-06-15 2002-12-12 일진나노텍 주식회사 Massive purification method of carbon nanotubes
KR100385867B1 (en) * 1999-06-15 2003-06-02 일진나노텍 주식회사 Method of synthesizing highly purified carbon nanotubes
KR100372331B1 (en) * 1999-06-15 2003-02-17 일진나노텍 주식회사 Method for gas phase purification of carbon nanotubes by thermal treatment in diffusion furnace
KR100382878B1 (en) * 1999-06-15 2003-05-09 일진나노텍 주식회사 Synthesis method of highly purified carbon nanotubes
US6413487B1 (en) 2000-06-02 2002-07-02 The Board Of Regents Of The University Of Oklahoma Method and apparatus for producing carbon nanotubes
US6919064B2 (en) 2000-06-02 2005-07-19 The Board Of Regents Of The University Of Oklahoma Process and apparatus for producing single-walled carbon nanotubes
JP3606232B2 (en) 2001-06-01 2005-01-05 富士ゼロックス株式会社 Carbon structure manufacturing apparatus and manufacturing method
KR20030003890A (en) * 2001-07-04 2003-01-14 한국화학연구원 Purification Method of Carbon Nanotubes for Hydrogen Storage
US6878361B2 (en) 2001-07-10 2005-04-12 Battelle Memorial Institute Production of stable aqueous dispersions of carbon nanotubes
US6896864B2 (en) 2001-07-10 2005-05-24 Battelle Memorial Institute Spatial localization of dispersed single walled carbon nanotubes into useful structures
KR100374042B1 (en) * 2001-07-11 2003-03-03 엘지전자 주식회사 Semiconductor device fabrication method using selective excluding process of carbon nanotube having various characteristics
JP3861747B2 (en) 2002-05-17 2006-12-20 株式会社豊田自動織機 Carbon nanotube purification method
US7364709B2 (en) * 2002-10-30 2008-04-29 Fuji Xerox Co., Ltd. Manufacturing apparatus and method for carbon nanotube
WO2004052782A1 (en) 2002-12-06 2004-06-24 Hokkaido Technology Licensing Office Co., Ltd. Nanocarbon-dissolving aqueous solution, aqueous solution for purification, and method of purification
JP4632285B2 (en) * 2003-05-27 2011-02-16 国立大学法人名古屋大学 Carbon nanotube production method and carbon nanotube-containing composition
TWI297709B (en) 2003-07-08 2008-06-11 Canon Kk Lens barrel
JP4296074B2 (en) * 2003-10-22 2009-07-15 富士通株式会社 Method for purifying carbon nanotube and method for producing carbon nanotube structure
EP1786727A1 (en) * 2004-08-03 2007-05-23 Universita'Degli Studi di Trieste Process of production of carbon nanotube rings
JP4552019B2 (en) * 2005-02-08 2010-09-29 国立大学法人群馬大学 Method for producing silicon carbide nanofiber
EP1967492B1 (en) 2005-11-29 2013-10-23 Meijo University Method for producing purified carbon nanotubes
JP2007230816A (en) * 2006-02-28 2007-09-13 Mitsubishi Heavy Ind Ltd Method for dispersing carbon material and apparatus for manufacturing carbon material
JP2008037695A (en) * 2006-08-04 2008-02-21 Mitsubishi Heavy Ind Ltd Nanocarbon material production apparatus and nanocarbon material purification method
TWI434904B (en) 2006-10-25 2014-04-21 Kuraray Co Transparent conductive film, transparent electrode substrate, and liquid crystal alignment film using the same, and carbon nanotube tube and preparation method thereof
EP2135842A4 (en) 2007-03-13 2012-04-04 Toyo Tanso Co Method for purifying carbon material containing carbon nanotube, carbon material obtained by the purification method, and resin molded body, fiber, heat sink, sliding member, field emission source material, conductive assistant for electrode, catalyst supporting member and conductive film, each using the carbon material
JP4966088B2 (en) * 2007-05-14 2012-07-04 日東電工株式会社 Carbon nanotube purification method
KR101197027B1 (en) 2010-08-18 2012-11-06 한국과학기술연구원 Method for purifying graphene powders
KR101883034B1 (en) * 2015-07-24 2018-07-27 주식회사 엘지화학 Process for preparing carbon nanotube fiber
CN107002306B (en) 2015-07-24 2020-05-12 Lg化学株式会社 Apparatus for manufacturing carbon nanotube fiber
CN114804077B (en) * 2022-05-18 2024-01-09 焦作集越纳米材料技术有限公司 Purification method and device for carbon nano tube

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010174419A (en) * 2009-01-30 2010-08-12 Showa Denko Kk Apparatus for removing iron-based impurities in vapor grown carbon fibers
JP2010174418A (en) * 2009-01-30 2010-08-12 Showa Denko Kk Method for removing iron-based impurities in vapor grown carbon fibers
US8449858B2 (en) 2009-06-10 2013-05-28 Carbon Solutions, Inc. Continuous extraction technique for the purification of carbon nanomaterials
US8454923B2 (en) 2009-06-10 2013-06-04 Carbon Solutions, Inc. Continuous extraction technique for the purification of carbon nanomaterials
KR20170041738A (en) * 2014-08-01 2017-04-17 광동 어글레이어 압토일렉트라닉 머티어리얼즈 컴퍼니 리미티드 Carbon nanotube-macromolecule composite layered transparent flexible electrode and preparation method therefor
KR101956145B1 (en) * 2014-08-01 2019-03-08 광동 어글레이어 압토일렉트라닉 머티어리얼즈 컴퍼니 리미티드 Carbon nanotube-macromolecule composite layered transparent flexible electrode and preparation method therefor

Also Published As

Publication number Publication date
JPH08198611A (en) 1996-08-06

Similar Documents

Publication Publication Date Title
JP2682486B2 (en) Method for purifying carbon nanotubes
Duesberg et al. Chromatographic size separation of single-wall carbon nanotubes.
JP4833546B2 (en) Method for sorting semiconducting carbon nanotubes
JP4754488B2 (en) Methods for the synthesis, separation and purification of powder materials
US7374685B2 (en) Process for separating metallic from semiconducting single-walled carbon nanotubes
Tarasov et al. Synthesis of carbon nanostructures by arc evaporation of graphite rods with Co–Ni and YNi2 catalysts
JP2005325020A (en) Screening method of semiconductor carbon nanotube
US20110011775A1 (en) Methods and apparatuses for purifying carbon filamentary structures
US8256695B2 (en) Method for purification of semiconducting single wall nanotubes
JPH06228824A (en) Method for purifying carbon-nanotube
JP3518586B2 (en) Method and apparatus for purifying carbon nanotube
US20040258604A1 (en) Apparatus and method for nanoparticle and nanotube production and use therefor for gas storage
JPH10120409A (en) Separation and purification of monolayered nanotube and separation ad purification of metal-including nanocapsule
Yu et al. Synthesis and electrochemical activities of TiC/C core-shell nanocrystals
JP2004168570A (en) Method for manufacturing soluble carbon nanotube
JP2006069850A (en) Method of refining carbon nanotube and carbon nanotube obtained by the refining method
RU2146648C1 (en) Method of preparing carbon nanotubes
JPS63303806A (en) Purification of diamond
JP2004323258A (en) Method of purifying carbon nanotube
CN1036061C (en) Preparation of diamond from graphite or carbonaceous solid matter
JP4463070B2 (en) Carbon nanotube purification method, purification apparatus, and purification kit
JPH0891816A (en) Purifying method of carbon single tube
KR100478144B1 (en) Method for Manufacturing Carbon Nanotube
JP3874269B2 (en) Carbon nanotube purification method
Belyakov Carbon nanotubes for the synthesis of ceramic matrix composites (cleaning, dispersion, surface modification)

Legal Events

Date Code Title Description
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 19970708

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20070808

Year of fee payment: 10

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20080808

Year of fee payment: 11

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20080808

Year of fee payment: 11

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20090808

Year of fee payment: 12

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20090808

Year of fee payment: 12

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20100808

Year of fee payment: 13

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20110808

Year of fee payment: 14

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20110808

Year of fee payment: 14

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20120808

Year of fee payment: 15

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20130808

Year of fee payment: 16

EXPY Cancellation because of completion of term