TWI247047B

TWI247047B - A microwave digestion method for elimination metal catalyst of carbon nanotubes

Info

Publication number: TWI247047B
Application number: TW93132899A
Authority: TW
Inventors: Mi Chen; Chieng-Ming Chen
Original assignee: Ming Hsin University Of Scienc
Priority date: 2004-10-29
Filing date: 2004-10-29
Publication date: 2006-01-11
Also published as: TW200613578A

Abstract

This invention is to provide a microwave digestion method for elimination metal catalyst of carbon nanotubes by placing carbon nanotubes in a Pyrex digestion tube with an acid mixture solution. Then a microwave digestion system is used to carry out microwave digestion. The acid solution can rapidly absorb microwave heat and energy, and therefore the heated acid solution can rapidly and completely dissolve metal which reside in the carbon nanotubes.

Description

1247047 九、發明說明：【發明所屬之技術領域】本發明係關於一種以微波消化法去除奈米碳管中金屬觸媒之方法，尤指一種可以快速去除奈米碳管中金屬粒子，且可有效保持完整奈米碳管管壁之方法，俾具有可以快速純化以及獲得向品質奈米碳管之優點及功效者。【先前技術】按，碳為週期表上IV族中最輕的元素，相較於其他同週期的元素具有其特殊㈣質。依照其鍵結與構造之不同，目前已發現了四種不同樣的型態，分別為： 1、石墨（Graphite) ··碳以Sp2的共價鍵鍵結成六重對稱的層狀結構，具有高的非等向性，可視為二維介間的半金屬（Two-dimensional semixnetal)。如第圖（a)所示。鑽石（Diamond) ·•碳的同素異構體，以乓俨鍵結而成，為具有接近等向性的三維空間材料。第一圖（b)所示。如 3、碳六十（Fullerene):碳以sp2鍵結，與相鄰的碳原子鍵結成五圓環形或六圓環形，為二古 po ^冬維空間形式的碳。如第一圖（C)所示。 1247047 奈米碳官（Carbon nanotubes):奈米碳管是在以電弧放％法‘作兔六十（Cm )時，被發現的一種直徑小於1 〇nm而長度可達〗μηι的空心管結構。如第一圖 (d )所示。其中，奈米碳管是由一層或多層不飽和石墨層 (Graphite layer)捲曲構成内部中空籠狀管，内徑大約 0.4〜l〇nm之間’外徑大約在lnm到數w 左右長度從數微米至數十微米不等。每—個碳都為sp2執域鍵結，碳管石墨層中央都是六圓環，而末端或轉折部分為五圓環^ 七圓環’如第二圖所示。單層奈米碳f依其捲曲的方式可分為扶手椅型（amehai〇、鑛齒型（A,)與螺旋型一(chiral)二種’依捲曲方式的不同有著不同的電性。如第 :圖所不，二維的石墨平面上可用兩個向量〜與％來表示，ch為chiral vector (見參考文獻j ): ch=na1+ma2 (n，m 為整數， 1、扶手椅型（麻㈣：碳管沿著（n，n)方向捲此型態的奈米碳管呈現金屬的電性，如第四圖⑴所示： 2、銀齒型（Zig-Zag ):碳營签 "" 棬此者U，0)或（0，n)方向捲曲’如第四圖（b)所示。〇四、螺旋型碳管沿著其它方向捲曲，如第 1247047 圖（c )所示。1247047 IX. Description of the Invention: [Technical Field] The present invention relates to a method for removing a metal catalyst in a carbon nanotube by microwave digestion, in particular, a method for rapidly removing metal particles in a carbon nanotube, and A method for effectively maintaining the integrity of the carbon nanotube wall, which has the advantages and functions of being able to be quickly purified and obtained to a quality carbon nanotube. [Prior Art] According to carbon, carbon is the lightest element of Group IV on the periodic table, and it has its special (four) quality compared to other elements of the same period. According to the different bonding and construction, four different types have been found, namely: 1. Graphite · Carbon is bonded to a six-fold symmetrical layered structure by the covalent bond of Sp2. The high anisotropy can be regarded as a two-dimensional semixnetal. As shown in Figure (a). Diamond • The allotrope of carbon, which is bonded by pong ,, is a three-dimensional space material with near isotropic properties. Figure (b) is shown in the first figure. Such as 3, carbon sixty (Fullerene): carbon is sp2 bonded, and adjacent carbon atoms are bonded into a five-circle or six-circle ring, which is the carbon in the form of two ancient po ^ winter space. As shown in the first figure (C). 1247047 Carbon nanotubes: The carbon nanotubes are a hollow tube structure with a diameter of less than 1 〇nm and a length of μμηι when the arc is used as the sixty (Cm) of the rabbit. . As shown in the first figure (d). Wherein, the carbon nanotube is composed of one or more layers of unsaturated graphite layer (Graphite layer) to form an inner hollow cage tube, and the inner diameter is between about 0.4 and 1 〇 nm. The outer diameter is about 1 nm to several w. Micron to tens of microns. Each carbon is sp2 domain bond, the carbon nanotube layer is six rings in the center, and the end or turning part is five rings ^ seven rings' as shown in the second figure. The single-layer nanocarbon f can be divided into an armchair type (amehai〇, mineral tooth type (A), and spiral type one (chiral) according to the way of crimping, which has different electrical properties depending on the crimping method. No.: The two-dimensional graphite plane can be represented by two vectors ~ and %, and ch is a chiral vector (see reference j): ch=na1+ma2 (n, m is an integer, 1. armchair type (Hemp (4): The carbon nanotubes roll the carbon nanotubes of this type along the (n, n) direction to exhibit the electrical properties of the metal, as shown in Figure 4 (1): 2. Silver-toothed (Zig-Zag): Carbon Camp Sign "" 棬者 U, 0) or (0, n) direction curl ' as shown in Figure 4 (b). 〇 Fourth, the spiral carbon tube curls in other directions, as shown in Figure 1247047 (c ) shown.

1992年後單層奈米碳管的電性開始被預測出來， Hamada (見參考文獻2)與如〇 (見參考文獻3)等人理料算出奈米石炭管的導電性。對以（m，n)型態為_之奈米碳管（zig-zag與chiral)，當（m，n)不為3的倍數時，Z 時奈米碳管呈現半導體的特性；若(m，n )為3的倍數時，則奈米碳管為半金屬的特性。由於奈米碳管擁有許多特質，例如質量輕、高強声、高韋刃性、可撓曲性、高表面積、高熱傳導性、導電度特異等（如表一所示），因此很多科學家開始對於奈米碳管的應用著手研究。表一奈米碳管的性質（見參考文獻4) j生質_ 尺寸 !層奈米碳管〇.6〜1.8 11111(管徑） |募他材比較電子束微影姓刻線寬 50nm到數nrn戽賓度 1.33〜1.40 g/cm3 鋁的密度：2.7g/cm3 彈性可彎曲極大角度且回覆後無損傷金屬與碳纖維於晶界處斷裂抗拉強度 45GPa 高強度合金鋼斷裂強度·· 2Pa 電流負載容量〜lxlO9 A/cm2 銅線於約lxl06A/cm2大小時溶斷場發射電極間距1 μιη時在錮金屬尖僅能在高電場 1247047The electrical conductivity of single-layer carbon nanotubes began to be predicted after 1992, and the conductivity of nano-carboniferous tubes was calculated by Hamada (see Reference 2) and Rugao (see Reference 3). For a carbon nanotube (zig-zag and chiral) in which the (m, n) type is _, when (m, n) is not a multiple of 3, the Z-phase carbon nanotube exhibits semiconductor characteristics; When m, n ) is a multiple of 3, the carbon nanotubes are semi-metallic in nature. Because carbon nanotubes have many qualities, such as light weight, high sound, high edge, flexibility, high surface area, high thermal conductivity, conductivity specificity (as shown in Table 1), many scientists have begun to The application of carbon nanotubes began to study. Table 1 properties of carbon nanotubes (see Reference 4) j Biomass _ Dimensions! Layer carbon nanotubes 〇.6~1.8 11111 (tube diameter) | Raise other materials compared to electron beam lithography surname line width 50nm to Number of nrn戽bin degrees 1.33~1.40 g/cm3 Density of aluminum: 2.7g/cm3 Elastic bendable maximum angle and no damage after repelling Metal and carbon fiber break at grain boundary Tensile strength 45GPa High strength alloy steel breaking strength·· 2Pa Current load capacity ~lxlO9 A/cm2 When the copper wire is about lxl06A/cm2, the field emission electrode spacing is 1 μιη when the metal tip is only at the high electric field 1247047.

________ 1〜3V能活化發光染料下50〜lOOV/μπι場發射且壽命有限熱穩吏性真空下能穩定至 2,80〇C，空氣中耐熱 me 微晶片上金屬線於 600〜1000°C熔融熱傳導室溫預剛值： 6000W/m.K ----— 鑽石：3320W/m.K 秦米碳管因具有特殊電子、機械、化學等特性，因此各種魔用元件及材料也應運而生，譬如·· 秦米碳管具有電性特質，故可應用於平面顯示器之場 ^ 射 _ 示器（Field Emission Display ; FED );奈米碳管具回強度、高韌性的特性且可組成新複合材料，故可運用於飛:機、太空梭材料；奈米碳管具有高強度、撓曲度、高韋刃性及導電性，因此比矽更適合作為電子顯微鏡（如掃描牙陵式顯微鏡（Scanning Tunnel Microscopy，STM)及原子力顯微鏡(Atomic Force Microscopy，AFM))的探針頭；奈米碳管的體積極為細小，再加上絕佳導電性與導熱性質’ 因此可以置於兩個金電極間’製做出極小的場效電晶體’ 此外，奈米碳管亦因為比面積大而成為一良好吸附材料之緣故（奈米碳管管道結構及多壁碳管之間的類石墨層空隙，使其可以有很高的儲存氫能力），因此更可應用作為能量儲存元件。 1247047 而目前較普遍的奈米碳管之製備方法，主要有以下幾________ 1~3V can activate the luminescent dye under 50~lOOV/μπι field emission and the life is limited. The thermal stability can be stabilized to 2,80〇C under vacuum. The heat in the air is on the microchip. The metal wire is melted at 600~1000°C. Heat conduction room temperature pre-rigid value: 6000W/mK ----- Diamond: 3320W/mK Since the Qinmi carbon tube has special electronic, mechanical and chemical properties, various magic components and materials have also emerged, such as ·· Qinmi carbon tube has electrical characteristics, so it can be applied to the Field Emission Display (FED) of the flat panel display; the carbon nanotube has the characteristics of return strength and high toughness and can form a new composite material. It can be used in fly: machine and space shuttle materials; carbon nanotubes have high strength, flexibility, high edge and conductivity, so it is more suitable as an electron microscope than Scanning Tunnel Microscopy (Scanning Tunnel Microscopy) , STM) and Atomic Force Microscopy (AFM) probe heads; the carbon nanotubes are extremely small in size, coupled with excellent electrical and thermal conductivity properties - so they can be placed between two gold electrodes do Very small field effect transistor' In addition, the carbon nanotubes are also a good adsorbent material because of the large specific area (the carbon nanotube tube structure and the graphite-like layer gap between the multi-wall carbon tubes make it possible to have It has a high storage capacity for hydrogen) and is therefore more suitable as an energy storage component. 1247047 The current preparation methods of the most common carbon nanotubes are as follows.

電弓瓜放電法（Arc discharge method) 1991年，以電弧放電法合成Qo時無意中發現奈米碳管（見參考文獻5)，此為電弧放電法首次被應用於成長奈米碳管。此方法的原理是在陽極碳棒上添加金屬觸媒（如··鐵、鈷、鎳），反應系統抽真空後通入惰性氣體，系統壓力維持在1〇到500 Torr。將約 30V的電壓，4〇到1〇〇安培的直流電接於兩個石墨電極上，當陽極慢慢靠近陰極，兩極會開始放電形成電孤’裝置如第五圖所示。碳與金屬觸媒高溫氣化並沉積於陰極上，這些碳質成分有奈米碳管、碳粒、c60 與大量的非晶質碳。電弧放電法可大量的產生奈米碳管’但是混有大量其它的雜相，純化的過程較不易。 2、雷身十蒸發法（Laser vaporization method) 雷射蒸發法是在1985年，由Rice大學R. E. Smalley實驗室所提出（見參考文獻6)，將金屬與碳合成的靶材置於高溫（約1，20(TC)反應爐中的石英管内’在氬氣環境下，利用高功率的雷射光聚焦後打在靶材上，使靶材表面上的碳高溫氣化，再藉由惰性 9 1247047 氣體將其帶到高溫爐外水冷銅收集器上。此方法可以得到較電弧放電法高的奈米碳管產率，所得到的奈米碳管為單層奈米碳管，管徑約lnm，並且碳管聚集排列成一束。儀器裝置如第六圖所示。 3 ' 化學氣相沉積（Chemical vapor deposition，CVD ) 此法最早是被用來製作碳纖維，利用一些含碳的氣體（見參考文獻7)，如CH4、C2H2、C2H4、C6H6…等碳氫化合物的氣體，通入高溫的石英管爐，碳氫化合物的氣體會因高溫分解成碳吸附在基板表面，而進行沉積成長。此方法可能得到奈米碳管、非晶質碳、實心碳纖維等。生長產物的品質與成長時間、溫度、氣源的種類、流量有密切關係。由於奈米碳管具有多種獨特的特性，故可運用於平面顯示器之電場發射器、顯微鏡的探針、氫燃料電池…等。近期内更有IBM公司成功的用奈米碳管取代傳統的矽製成積體電路。如此廣泛的運用，顯見產業界對於奈米碳管有很大的需求量，惟，由於奈米碳管在製備過程中容易殘留金屬觸媒在奈米碳管管壁上，且殘留之金屬觸媒會影響奈米碳管之品質導致無法完全發揮其特性，因此，如何消除殘留金屬觸媒以獲取高純度、高品質奈米碳管之技術及 10 1247047 方法有越來越被重視之趨勢。 1993年，Tsang (見參考文獻8)等人在空氣中75(Γ(：的條件下，以氧化法純化多層管壁奈米碳管，利用多層管壁奈米碳管與奈米微粒熱穩定性的差異，燃燒去除唉微粒子，後來又有許多的研究者（見參考文獻9-11 )利用熱退火或類似熱氧化的方法純化奈米碳管，但得到的碳管產率相當低。1998年’ Shelimov (見參考文獻12 )等人使用超音波補助微過濾方法去除微碳粒與金屬觸媒，得到純度大於90%，產率30-70%之純化奈米碳管。2001年Moon (見參考文獻13)等人使用熱退火去除微碳粒子，以HC1強酸溶解金屬觸媒，再用PTFF薄膜過濾，純化後的奈米碳管金屬觸媒含量少於1。2002年，Chattopadhyay (見參考文獻14)等人使用HNO3完全去除奈米碳管中的金屬觸媒。Chen (見參考文獻15 )等人利用三階段的純化程序，在沒有破壞碳管的情況下’完全去除金屬觸媒。大部分的研究者都使用HF、H2S04、HNO;、HC1等強酸溶解奈米碳管中的金屬觸媒，有時使用超音波輔助，再以薄膜過濾，就這樣反覆的重複這些程序，需花費較長的時間，才可得到較高的純化產率。而且在長時間的強酸溶劑處理下，奈米碳管可能被切斷’或者碳管璧遭到破壞。由此可 1247047 見，截至目前為止尚未有一種可在不破壞奈米碳管管壁之情況下，快速去除多層管壁奈米碳管中金屬觸媒之較佳方法問世。有鑑於此，吾等發明人遂構思針對去除奈米碳管中金屬觸媒之方法進行研發，期提供一種不破壞奈米碳管管壁且可快速去除金屬觸媒之方法，並在經過不斷實驗及測試後而有本發明之問世。【發明内容】緣是，本發明之目的係為了提供一種以微波消化法去除奈米碳管中金屬觸媒之方法，尤指一種可以快速去除奈米碳管中金屬粒子，且可有效保持完整奈米碳管壁之微波消去法，俾具有可以快速純化以及獲得高品質奈米碳管之優點及功效者。為達致以上目的，本發明人特別研發一種以微波消化法去除奈米碳管中金屬觸媒之方法，係將利用化學氣相沉積法製備取得之奈米碳管基材，置入1 : 1混合的硝酸 (HN〇3)與鹽酸（HC1)溶液中，然後置入微波消化系統中，分二階段進行微波消化，微波消化完成後冷卻形成懸浮液體，然後將懸浮液體以去離子水清洗，再用Ο.ίμηι聚四氟乙烯（Polytetrafluoroethylene，PTFE)膜過濾，重複 1247047 以去離子水清洗過;慮至滤液澄清不含酸液’再將奈米碳管基材以乙醇清洗、乾燥後，即可得純化之奈米碳管基材，俾達致快速純化以及獲得高品質奈米碳管之優點及功效者。在上述方法中，該微波消化過程之第一階段微波消化處理係設定加熱20分鐘，使溫度上升至210°C。在上述方法中’該微波消化過程之第二階段微波消化處理係將溫度維持在210°C並加熱30分鐘。在上述方法中，該微波消化之微波功率設定為1⑻W。【實施方式】關於本發明人藉以達致上述目的而採用之技術手段，茲舉一種較佳實施例配合圖式於下文進行詳細說明，俾供鈞上深入了解並認同本發明。首先請參閱第七圖之流程圖所示，本發明主要包含下列步驟：一、製備奈米碳管：本發明係以微波電漿化學氣相沉積法（Microwave Plasma Chemical Vapor Deposition，MPCVD)或電子迴旋共振化學氣相沈積法（Electron cyclotron resonance Chemical Vapor Deposition，ECRCVD)製備 1247047 奈米碳管基材，分別詳述如下： 1、微波電漿化學氣相沉積法，其設備裝置圖係如第八圖所示，主要分成三部分：（A)反應氣體輸送系統：氣體的流量可由氣體控制器及質流電子控制器組合來精確地控制其流量，在管路末端混合後，再導入反應室中。（B)微波輸出系統：氣體進入反應室後，受到導波管傳來的微波而激發形成電漿。微波發生器是由曰本東京電子株式會社所製造，頻率2.54GHz，最太輸出功率1.3KW連接内層鍍鋁之導波管可將微波傳送至反應區，調整導波管上的調合器及plunger，使反射波減低至最小，最後可得所需要的圓球形電漿。（C) 反應室及真空排氣系統··反應室由石英管製成，反應氣體混合後由反應室上端進入。頂端為一個操作視窗，利用鏡子以利觀察電漿。排氣系統的迴轉式幫浦，可將真空抽至l〇_2torr以下。壓力的控制是由抽氣閥控制器之控制閥門開口的程度調整抽氣量而成，壓力的量測是以torr為單位讀出。續將以微波電漿化學氣相沉積法製造奈米碳管之製備過程及沉積條件等參數詳述如下： (1 )基板前處理：先將石夕晶圓n-type (10)用滅鍍法 1247047 (sputtering)將鐵（Fe)鍍在石夕晶片上（10nm/4 忖），鐵做為觸媒以利成長多層管壁奈米碳管。基板表面經上述方法處理過後，將基板切割成統一的尺寸（1 cm X1 cm )，將其放入沈積用的反應室中。 (2) 參數設定：Arc discharge method In 1991, the carbon nanotubes were inadvertently discovered when synthesizing Qo by arc discharge method (see Reference 5). This is the first time that the arc discharge method has been applied to the growth of carbon nanotubes. The principle of this method is to add a metal catalyst (such as iron, cobalt, nickel) to the anode carbon rod, and the reaction system is evacuated to pass an inert gas, and the system pressure is maintained at 1 Torr to 500 Torr. A voltage of about 30 V, a DC current of 4 Torr to 1 ampere is connected to the two graphite electrodes. When the anode is slowly approaching the cathode, the two electrodes start to discharge to form an electric orphan device as shown in the fifth figure. Carbon and metal catalysts are vaporized at high temperature and deposited on the cathode. These carbonaceous components are carbon nanotubes, carbon particles, c60 and a large amount of amorphous carbon. The arc discharge method can produce a large amount of carbon nanotubes' but mixed with a large amount of other heterophases, and the purification process is relatively difficult. 2, Laser vaporization method (Laser vaporization method) Laser evaporation method was proposed in 1985 by Rice University RE Smalley laboratory (see Reference 6), the metal and carbon synthesis target placed at high temperature (about 1,20 (TC) in the quartz tube inside the furnace 'under argon atmosphere, using high-power laser light to focus on the target, so that the carbon on the surface of the target gasification at high temperature, and then by inertia 9 1247047 The gas is taken to the water-cooled copper collector outside the high-temperature furnace. This method can obtain the carbon nanotube yield higher than the arc discharge method, and the obtained carbon nanotube is a single-layer carbon nanotube with a diameter of about 1 nm. And the carbon tubes are gathered into a bundle. The instrument is shown in Figure 6. 3 'Chemical vapor deposition (CVD) This method was first used to make carbon fibers, using some carbon-containing gases (see reference). In the literature 7), hydrocarbon gases such as CH4, C2H2, C2H4, C6H6, etc. are introduced into a high-temperature quartz tube furnace, and the hydrocarbon gas is decomposed into carbon on the surface of the substrate due to high temperature decomposition, and deposition is carried out. Method may get Carbon nanotubes, amorphous carbon, solid carbon fiber, etc. The quality of the growth product is closely related to the growth time, temperature, type of gas source, and flow rate. Because of its unique characteristics, the carbon nanotubes can be used in flat panel displays. The electric field emitter, the probe of the microscope, the hydrogen fuel cell, etc. In the near future, IBM has successfully replaced the traditional tantalum with a carbon nanotube to make an integrated circuit. Such a wide application, it is obvious that the industry for the nano There is a large demand for carbon tubes. However, since the carbon nanotubes tend to remain on the surface of the carbon nanotube tubes during the preparation process, the residual metal catalyst may affect the quality of the carbon nanotubes. Fully exploiting its characteristics, therefore, how to eliminate residual metal catalysts to obtain high-purity, high-quality carbon nanotubes and the 10 1247047 method is gaining more and more attention. In 1993, Tsang (see Reference 8), etc. Purification of multi-layer tube-walled carbon nanotubes by oxidation in the air under conditions of 75 (Γ(:), using the difference in thermal stability between the multi-layered tube-nano carbon nanotubes and the nanoparticles, burning to remove 唉 micro Particles, and later many researchers (see references 9-11) used thermal annealing or a similar thermal oxidation method to purify carbon nanotubes, but the carbon tube yield was quite low. 1998 Shelimov (see references) 12) et al. used ultrasonic-assisted microfiltration to remove micro-carbon particles and metal catalysts to obtain purified carbon nanotubes with a purity greater than 90% and a yield of 30-70%. 2001 Moon (see Reference 13) et al. The micro-carbon particles were removed by thermal annealing, and the metal catalyst was dissolved in HC1 strong acid, and then filtered with PTFF film. The purified carbon nanotube metal catalyst content was less than 1. In 2002, Chattopadhyay (see Reference 14) and others used HNO3 completely removes the metal catalyst in the carbon nanotubes. Chen (see Reference 15) and others used a three-stage purification procedure to completely remove the metal catalyst without destroying the carbon nanotubes. Most researchers use HF, H2S04, HNO; strong acid such as HC1 to dissolve the metal catalyst in the carbon nanotubes, sometimes using ultrasonic assist, and then filtering with the membrane, so repeating these procedures repeatedly, it takes Higher purification yields are obtained over a longer period of time. Moreover, under the treatment of a long acid solvent, the carbon nanotubes may be cut off or the carbon nanotubes may be destroyed. Thus, as seen from 12,470,47, there has not been a preferred method for rapidly removing metal catalysts in multi-walled nanotube carbon nanotubes without destroying the carbon nanotube wall. In view of this, our inventors have conceived a method for the removal of metal catalysts in carbon nanotubes, providing a method for rapidly removing the metal catalyst without destroying the carbon nanotube wall and continuing The invention has been made after the experiment and the test. SUMMARY OF THE INVENTION The purpose of the present invention is to provide a method for removing metal catalyst in a carbon nanotube by microwave digestion, especially to quickly remove metal particles in a carbon nanotube, and to effectively maintain integrity. The microwave elimination method of the carbon nanotube wall has the advantages and functions of rapid purification and high quality carbon nanotubes. In order to achieve the above object, the present inventors have specially developed a method for removing a metal catalyst in a carbon nanotube by microwave digestion, which is a method for preparing a carbon nanotube substrate by chemical vapor deposition, and placing 1: 1 mixed nitric acid (HN〇3) and hydrochloric acid (HC1) solution, then placed in the microwave digestion system, microwave digestion in two stages, microwave digestion is completed, cooling to form a suspension liquid, and then the suspension liquid is washed with deionized water Then, use Ο.ίμηι polytetrafluoroethylene (PTFE) membrane filtration, repeat 1247047 to wash with deionized water; take into account that the filtrate is clear without acid solution' and then clean the nano carbon nanotube substrate with ethanol and dry The purified carbon nanotube substrate can be obtained, and the advantages and functions of the high-quality carbon nanotubes can be obtained by rapid purification and purification. In the above method, the microwave digestion treatment in the first stage of the microwave digestion process is set to be heated for 20 minutes to raise the temperature to 210 °C. In the above method, the second stage of the microwave digestion process of the microwave digestion process maintains the temperature at 210 ° C and heats for 30 minutes. In the above method, the microwave power of the microwave digestion is set to 1 (8) W. [Embodiment] The present invention has been described in detail with reference to the preferred embodiments of the present invention. First, please refer to the flow chart of the seventh figure. The present invention mainly comprises the following steps: 1. Preparation of carbon nanotubes: The invention is based on Microwave Plasma Chemical Vapor Deposition (MPCVD) or electrons. The 1247047 carbon nanotube substrate was prepared by Electron cyclotron resonance chemical vapor deposition (ECRCVD), which are described in detail as follows: 1. Microwave plasma chemical vapor deposition method, the equipment device diagram is as the eighth As shown in the figure, it is mainly divided into three parts: (A) Reactive gas delivery system: the flow of gas can be precisely controlled by a combination of gas controller and mass flow electronic controller, mixed at the end of the pipeline, and then introduced into the reaction chamber. . (B) Microwave output system: After the gas enters the reaction chamber, it is excited by the microwave from the waveguide to form a plasma. The microwave generator is manufactured by Sakamoto Tokyo Electronics Co., Ltd., with a frequency of 2.54 GHz and a maximum output power of 1.3 KW. The inner layer of aluminum-plated waveguide can transmit microwaves to the reaction zone, and adjust the blender and plunger on the waveguide. In order to minimize the reflected wave, the desired spherical plasma is finally obtained. (C) Reaction chamber and vacuum exhaust system · The reaction chamber is made of quartz tube, and the reaction gas is mixed and then enters from the upper end of the reaction chamber. The top is an operating window that uses a mirror to facilitate viewing of the plasma. The rotary pump of the exhaust system pumps the vacuum below l〇_2torr. The pressure is controlled by the degree to which the suction valve controller controls the opening of the valve. The measurement of the pressure is read in units of torr. The parameters such as the preparation process and deposition conditions for the preparation of carbon nanotubes by microwave plasma chemical vapor deposition are detailed as follows: (1) Pre-treatment of the substrate: first use the stone-plated wafer n-type (10) Method 1247047 (sputtering) iron (Fe) is plated on a stone wafer (10nm / 4 忖), iron as a catalyst to facilitate the growth of multi-layer tube wall carbon nanotubes. After the surface of the substrate was treated by the above method, the substrate was cut into a uniform size (1 cm X1 cm) and placed in a reaction chamber for deposition. (2) Parameter setting:

基材：n-type(lOO)石夕晶片鍍上100nm的鐵微波功率：300W 壓力：lOtorr 沈積時間：10分鐘進料氣體：co2、ch4 DC BIAS ·· 100mA (3) MPCVD操作步驟： a、將試片放在石墨圓盤上，升至微波導管之高度。（反應室中間的位置） b、將反應室的壓力抽至2xl(T2torr以下。 c、通入已設定好流量之混合氣體，經過一段時間後，即讓壓力上升至設定之值。 d、在功率上升之際，即開啟微波，缓慢升至所需之功率值，輕微調整調和器（tuner)電漿即 1247047 可出現。 e、沈積時間到達時關閉微波，使試片之溫度缓慢下降，稍後才關閉氣體。 f、取出試片進行析出物的分析。 2、電子迴旋共振化學氣相沈積法（Electron cyclotron resonance Chemical Vapor Deposition，ECRCVD)，其設備裝置圖係如第九圖所示，電子迴旋共振是利用微波電源和導波管（waveguide)，使氣體在高真空的電漿氣室（plasma chamber)被游離為電漿（plasma) 。氣室外繞以線圈，通電流造成磁場，以限制電子執道，以增加氣體游離率，提高電漿密度。晶圓置於電位接地的基板（substrate)上，放在沈積氣室 (deposition chamber)，以完成化學氣相沈積。ECR是一種高密度電漿，可將有機化學先導氣體分解使其產生化學重組，而達到高品質的薄膜成長效果（但成長的速率不夠高是其唯一的缺憾）。續將以電子迴旋共振化學氣相沈積法製造奈米碳管之處理方式及沉積條件等參數詳述如下： (1 )基板前處理：先將石夕晶圓p-type (111)用濺鑛法將鈷（Co)鍍在矽晶片上（約厚7·5ηπι/4吋），再利用 16 1247047 ECRC VD成長多層管壁奈米碳管。 (2)參數設定：Substrate: n-type (100) Shixi wafer coated with 100nm iron microwave power: 300W pressure: lOtorr deposition time: 10 minutes feed gas: co2, ch4 DC BIAS · · 100mA (3) MPCVD operation steps: a, The test piece was placed on a graphite disc and raised to the height of the microwave catheter. (Position in the middle of the reaction chamber) b. Pump the pressure in the reaction chamber to 2xl (below T2torr. c. Pass the mixed gas with the set flow rate, and after a period of time, let the pressure rise to the set value. d, When the power rises, the microwave is turned on and slowly rises to the required power value. A slight adjustment of the tuner plasma, 1247047, can occur. e. When the deposition time arrives, the microwave is turned off, and the temperature of the test piece is slowly lowered. After the gas is turned off, f. The test piece is taken out for analysis of the precipitate. 2. Electron cyclotron resonance chemical vapor deposition (ECRCVD), the device device diagram is as shown in the ninth figure, and the electron The cyclotron resonance uses a microwave power source and a waveguide to cause the gas to be liberated into a plasma in a plasma chamber of a high vacuum. The gas is wound around the coil to generate a magnetic field to limit the current. Electronic obstruction to increase the gas liberation rate and increase the plasma density. The wafer is placed on a grounded substrate and placed in a deposition chamber (deposition chamb) Er) to complete chemical vapor deposition. ECR is a high-density plasma that decomposes organic chemical lead gas to produce chemical recombination to achieve high-quality film growth (but the growth rate is not high enough) The defects are as follows: The processing methods and deposition conditions for the production of carbon nanotubes by electron cyclotron resonance chemical vapor deposition are detailed as follows: (1) Substrate pretreatment: firstly, the Shixi wafer p-type (111) Cobalt (Co) is plated on a ruthenium wafer by sputtering method (about 7·5 ηπι/4 厚), and then multi-layer tube-walled carbon nanotubes are grown by using 16 1247047 ECRC VD. (2) Parameter setting:

基材：P-type(lll)矽晶片鍍上7 5nm的銘功率：800WSubstrate: P-type (lll) 矽 wafer plated with 7 5nm Ming Power: 800W

壓力：lOtorr 反應溫度：600°C 進料氣體：H2(2sccm)、CH4(18sccm) 二、奈米碳管之特性分析： 1、以Hitachi S-4700I掃描式電子顯微鏡（Scanning ElectronMicroscope，SEM)，利用掃插式電子顯微鏡觀察表面形態及晶形變化的情形，如第十圖戶斤示。 2、以Philips Techai-20高解析穿遂式電子顯微鏡 (High Resolution Transmission Electron Microscope, HRTEM)是由電子穿過試片，經電磁透鏡系統的透鏡放大效應，而得高倍率的影象。 3、以拉曼光譜儀（Raman Spectroscope，Renishaw system 200 )測定碳管之特性，如第十一圖所示。拉曼光譜分析是利用氬氣產生波長514.5nm的雷射’照射在試片表面，偵測其散射光譜。碳在波數1332 αιΓ1處有 17 1247047 式直接對溶液進行加熱，不需經過容器傳遞熱量，因此可提升加熱的速率，降低熱能在傳導的過程中散失。故使用微波加熱可以明顯縮短樣品消化所需的時間，故本發明選用微波消化的方式來進行基材的純化。 2、微波消化純化奈米碳管之操作程序：利用微波消化系統溶解殘留在奈米碳管中的金屬觸媒，先以工具 (如刀子）刮下晶圓上的基材試樣，置入Pyrex消化瓶内，加入1 : 1混合的5M石肖酸（HN〇3)和5M 鹽酸（HC1)溶液，置入微波消化系統中，微波功率設定為100W，分二階段進行微波消化；第一階段加熱20分鐘使溫度上升至210°C，第二階段溫度維持在210°C加熱30分鐘，微波消化完成後冷卻，將懸浮液體以去離子水清洗後，再用Ο.ΐμπι聚四氟乙稀（Polytetrafluoroethylene，PTFE)膜過濾，重複以去離子水清洗過濾，至濾液澄清不含酸液，再將濾膜上之試樣以乙醇清洗、乾燥後，可得純化之碳物質。四多層管壁奈米碳管之特性分析：純化後可由穿遂式電子顯微鏡觀察多層管壁奈米碳 19 1247047 管之結構及純化的程度，可由熱重分析系統估計金屬觸媒所殘留的量，使用熱重分析系統1020 Series TGA 7 Thermal Analysis System (TGA)，如第十四圖所示。物質會隨著環境溫度的上升或下降而改變其重量之分析謂之為熱重量分析。例如物質在某一溫度下減少重量，表示物質在此溫度產生蒸發或分解，如果物質在某溫度範圍内重量沒有損失即表示該物質在此溫度範圍是呈現安定狀態。量測物質在各不同溫度下之重量可以判斷化合物之成份及混合物中各成份之含量。熱重分析儀器分析的合適樣品重量約為5到10毫克，並於室溫加熱至900°C。本發明設定以升溫速率20°C/min由30°C加熱至900°C在空氣流率lOsccm。酸處理後的基材試樣藉由熱重分析系統測定溫度在空氣中氧化45分鐘。最後分別取純化前後之奈米碳管基材試樣作比較，可獲以下結果： 1、微波消化處理前後之差異：請參閱第十五圖所示之未經微波消化處理之奈米碳管透過低倍率穿遂式電子顯微鏡觀察之影像，在該圖中顯示出在多層奈米碳管壁中有雜質，例如：非結晶質碳、石墨和金屬粒子。金屬粒子明顯的嵌在多層管壁奈米碳管的頂端或在碳管中間。在穿 20 1247047 遂式電子顯微鏡影像中可觀察到，碳管結構為多層管壁奈米碳管且直徑為10〜30nm。而第十六圖所示則為經過微波消化純化後的多層管壁奈米碳管透過低倍率穿遂式電子顯微鏡觀察之影像，由該圖中可觀察金屬粒子大部份已被 · 去除，其多層管壁奈米碳管的結構和管壁並沒有被破壞。. 由此可知硝酸（HN〇3)溶解金屬粒子之效果顯著，且鹽酸 (HC1)在浴解氧化金屬成效頗佳。因為硝酸係為強氧化劑，故可將非結晶質礙去除，再加上在微波系統中，無機· 酸如硝酸（HN〇3)和鹽酸（HC1)溶液會快速的吸收微波月b與熱，因此不須攪拌就可在一小時内快速溶解殘留在奈米碳管管壁上之金屬粒子。而第十七圖則係顯示經由酸處理的多層官壁奈米碳管透過穿遂式電子顯微鏡觀察之影像，該圖面顯示出多層管壁奈米碳管的末端被打開但管壁的石墨結構並未被破壞’碳管直徑約2。鲁由此可以證明減低酸濃度及浸泡在酸液的時間可有效的完全保持奈米碳管壁，且利用微波辅助消化系統去除 · 金屬觸媒，兩階段酸處理的消化時間只需花費不到一小時 · 之時間即可完成，也就是說微波消化是去除碳管中金屬粒子極佳且快速的方法。 2、微波消化處理前後之熱重分析圖差異：本發明主 21 1247047 要係利用熱重分析系統燃燒以去除奈米碳管基材中之非碳管物質，並藉以測量殘留在奈米碳管基材中金屬觸媒之重量百分比（wt%)，同時可以用來檢測奈米碳管在空氣燃燒溫度。請參閱第十八圖所示微波消化處理前之奈米碳管熱重分析圖，圖面顯示處理前之基材試樣大約在410°c時開始減少重量，而在730°C左右時多層管壁奈米碳管完全消失，經測量後發現燃燒後所剩的金屬觸媒約為奈米碳管基材原來重量的30 wt%。第十九圖則係微波消化處理後之奈米碳管熱重分析圖，由圖面中可看到基材試樣在30°C到 450°C這個階段所減少的重量是很慢的，為水份和非結晶碳的損失；在45CTC到650°C的溫度範圍則可發現重量明顯減少（即650°C左右時多層管壁奈米碳管完全消失），經測量後發現燃燒後所剩的金屬觸媒僅存奈米碳管基材原來重量的5.25wt%左右。由此可以證明微波消化方法對多層管壁奈米碳管是有效的純化方法，且利用熱重分析系統來估計純化多層管壁奈米碳管的重量百分比是一種極佳而精確的方法。 3、微波消化處理前後之拉曼光譜分析圖差異：從第十二圖可以看出在未進行微波消化法之多層奈米石炭管中的D波數強度比G波數要大，由此可見純化前之多層奈米碳 22 1247047 管中非晶質碳的結構較多；而在第二十圖則顯示純化後之多層奈米碳管的D波數強度降底比G波數要小，由此遂可證明利用微波消化是可以提高多層奈米碳管的純度。經由以上說明及純化前後之數據比較可以確定，本發明利用微波消化系統做純化處理可得到高產率的多層管壁奈米碳管。在微波系統中，硝酸（HN〇3)和鹽酸（HC1) 很快吸收微波熱能而完全溶解金屬觸媒，純化處理過程不但沒有破壞奈米碳管管璧，還能達到高品質奈米碳管。微波輔助和酸處理系統中溶解多層管壁奈米碳管中的金屬成分，兩階段微波消化的過程在一個小時左右即可完成，縮減純化時間而可提升處理效率。純化後，基材試樣中的金屬觸媒由原來的30 wt%降低到5.15 wt%。結果顯示，多層管壁奈米碳管的管壁未被破壞且所含的金屬大約只有5 wt%。換言之，使用微波消化法可有效去除奈米碳管中殘留之金屬觸媒而得以純化多層管壁奈米碳管。再者，本發明所提供之方法除可適用於多層管壁奈米碳管以外，當然亦可運用於單層管壁奈米碳管上，其微波消化輔助酸處理過程並無不同，且亦可發揮相同功效並獲致高品質奈米碳管，合予敘明。由以上說明可知，本發明之最大特點在於藉助微波加 23 1247047 熱含浸奈米碳管基材之酸溶液，以加速消化去除奈米峻管中殘留的金屬觸媒，至於所採用之酸溶液種類、濃度，以及微波時間、溫度、功率等數值則並非絕對受到侷限，在本說明書中所揭示者僅為實驗過程中所採用之較佳情形之數值，完全不排除在同樣運用微波加熱消化去除奈米碳管中殘留之金屬觸媒時還會有其他可行之數值組合，而其當亦為本發明之專利範圍所含括。綜上所述，本發明之「以微波消化法去除奈米碳管中金屬觸媒之方法」所揭露之技術手段確能有效解決習知處理方式之問題，並達致獲致高純度奈米碳管、保持奈米碳管管壁完整、以及縮短處理時間等目的及功效，洵屬利用自然法則之技術思想之創作而為專利法所稱之發明無誤，爰依法提出申請，懇祈鈞上惠予詳審並賜准專利，至感德馨。唯以上所述者，僅為本發明之較佳實施例而已，當不能以之限定本發明之專利範圍，故舉凡運用本說明書申請專利範圍内容所為之等效結構變化，理皆包含於本發明之專利範圍中。【圖式簡單說明】第一圖所示係碳同素異形結構示意圖。 24 1247047 第二圖所示係奈米碳管結構示意圖。第三圖所示係二維的石墨平面示意圖。第四圖所示係單層管壁奈米碳管模型示意圖。第五圖所不係電弧放電設備不意圖。第六圖所示係雷射蒸發設備示意圖。第七圖所示係本發明之流程圖。第八圖所示係MPCVD設備示意圖。第九圖所示係ECRCVD設備示意圖。第十圖所示係多層管壁奈米碳管之SEM圖。第Η—圖所示係拉曼光譜儀設備示意圖。第十二圖所示係純化處理前多層管壁奈米碳管之拉曼分析圖。第十三圖所示係本發明使用之微波消化系統。第十四圖所示係本發明使用之熱重分析系統。第十五圖所示係微波消化處理前的多層管壁奈米碳管之 ΤΕΜ 圖。第十六圖所示係微波消化純化後的多層管壁奈米碳管之 ΤΕΜ 圖。第十七圖所示係微波消化純化後的多層管壁奈米碳管之 HRTEM Μ ° 25 1247047 第十八圖所示係微波消化處理前之熱重分析圖。第十九圖所示係純化處理後之熱重分析圖。第二十圖所示係純化處理後多層管壁奈米碳管之拉曼分析圖。【參考文獻】 1. R. Saito? G. Dresselhaus, M. S. Dresselhaus, u Physical properties of Carbon Nanotubes’’，Imperial College Press，London，（1998) 2. N. Hamada，S. Sawada，A. Oshiyama，Phys· Rev· Lett·，1992 68 1581 3. R. Saito, M. Fujita，G. Dresselhaus, M. S. Dresselhaus，Appl.Pressure: lOtorr Reaction temperature: 600 °C Feed gas: H2 (2sccm), CH4 (18sccm) Second, the characteristics of the carbon nanotubes: 1, with Hitachi S-4700I scanning electron microscope (SEM), The surface morphology and the change of the crystal shape were observed by a scanning electron microscope, as shown in the tenth figure. 2. The Philips High Resolution Transmission Electron Microscope (HRTEM) is a high-magnification image obtained by passing electrons through the test piece and through the lens amplification effect of the electromagnetic lens system. 3. The characteristics of the carbon tube were measured by Raman Spectroscope (Renishaw system 200) as shown in Fig. 11. The Raman spectroscopy is performed by irradiating a laser beam having a wavelength of 514.5 nm with argon gas on the surface of the test piece to detect the scattering spectrum. Carbon has a wave number of 1332 αιΓ1. 17 1247047 directly heats the solution without transferring heat through the container, thus increasing the rate of heating and reducing the loss of thermal energy during conduction. Therefore, the use of microwave heating can significantly shorten the time required for sample digestion, so the present invention uses microwave digestion to purify the substrate. 2. Microwave digestion and purification of carbon nanotubes: using a microwave digestion system to dissolve the metal catalyst remaining in the carbon nanotubes, first scraping off the substrate sample on the wafer with a tool (such as a knife), placing Pyrex digestive flask, adding 1:1 mixed 5M sulphuric acid (HN〇3) and 5M hydrochloric acid (HC1) solution, placed in the microwave digestion system, microwave power set to 100W, microwave digestion in two stages; The stage is heated for 20 minutes to raise the temperature to 210 ° C, the second stage temperature is maintained at 210 ° C for 30 minutes, microwave digestion is completed and then cooled, the suspension liquid is washed with deionized water, and then Ο.ΐμπι polytetrafluoroethylene The membrane is filtered by a polytetrafluoroethylene (PTFE) membrane, repeatedly filtered with deionized water, and the filtrate is clarified to contain no acid solution. The sample on the membrane is washed with ethanol and dried to obtain a purified carbon material. Characterization of four-layer tube-walled carbon nanotubes: After purification, the structure and purification degree of the multi-layer tube nanocarbon 19 1247047 tube can be observed by a penetrating electron microscope. The residual of the metal catalyst can be estimated by the thermogravimetric analysis system. For the amount, use the Thermogravimetric Analysis System 1020 Series TGA 7 Thermal Analysis System (TGA) as shown in Figure 14. The analysis of matter that changes its weight as the ambient temperature rises or falls is called thermogravimetric analysis. For example, a substance reduces its weight at a certain temperature, indicating that the substance evaporates or decomposes at this temperature. If the substance does not lose weight within a certain temperature range, it means that the substance is in a stable state in this temperature range. The weight of the substance at various temperatures can be used to determine the composition of the compound and the amount of each component in the mixture. A suitable sample for thermogravimetric analysis is about 5 to 10 mg in weight and heated to 900 ° C at room temperature. The present invention is set to be heated from 30 ° C to 900 ° C at a heating rate of 20 ° C / min at an air flow rate of 10 sccm. The acid-treated substrate sample was oxidized in air for 45 minutes as measured by a thermogravimetric analysis system. Finally, the samples of the carbon nanotube substrate before and after purification were separately compared, and the following results were obtained: 1. Differences before and after microwave digestion: Please refer to the microwave-digested carbon nanotubes shown in Figure 15 The image observed through a low magnification penetrating electron microscope shows impurities in the walls of the multilayered carbon nanotubes, such as amorphous carbon, graphite, and metal particles. The metal particles are clearly embedded in the top of the multilayer tube wall carbon nanotube or in the middle of the carbon tube. It can be observed in the image of the 20 1247047 遂-type electron microscope that the carbon tube structure is a multi-layer tube-wall carbon nanotube and has a diameter of 10 to 30 nm. The sixteenth figure shows the image of the multi-layer tube-walled carbon nanotubes purified by microwave digestion through a low-magnification penetrating electron microscope. Most of the metal particles observed in the figure have been removed. The structure and wall of the multi-layer tube-walled carbon nanotubes are not destroyed. From this, it is known that nitric acid (HN〇3) has a remarkable effect of dissolving metal particles, and hydrochloric acid (HC1) has a good effect in deoxidizing metal in a bath. Because nitric acid is a strong oxidant, the non-crystalline barrier can be removed. In addition, in the microwave system, inorganic acid such as nitric acid (HN〇3) and hydrochloric acid (HC1) solution can quickly absorb the microwave b and heat. Therefore, the metal particles remaining on the wall of the carbon nanotube tube can be quickly dissolved in one hour without stirring. The seventeenth figure shows an image of a multi-layered nanotube-nanocarbon tube treated with acid through a penetrating electron microscope, which shows the end of the multi-layer tube-walled carbon nanotube but the graphite of the tube wall The structure has not been destroyed' carbon tube diameter is about 2. Lu can thus prove that reducing the acid concentration and immersing in the acid solution can effectively maintain the carbon nanotube wall completely, and use the microwave-assisted digestion system to remove the metal catalyst. The digestion time of the two-stage acid treatment can be less than It takes one hour to complete, which means that microwave digestion is an excellent and fast way to remove metal particles from carbon tubes. 2. Differences in thermogravimetric analysis before and after microwave digestion: The main 21 1247047 of the present invention is to be burned by a thermogravimetric analysis system to remove non-carbon tubes in the carbon nanotube substrate, thereby measuring residuals in the carbon nanotubes. The weight percentage (wt%) of the metal catalyst in the substrate can also be used to detect the carbon burning temperature of the carbon nanotubes. Please refer to the thermogravimetric analysis of the carbon nanotubes before the microwave digestion treatment shown in Figure 18. The figure shows that the substrate sample before treatment starts to reduce weight at about 410 ° C, and at 730 ° C or so. The tube-nanocarbon tube disappeared completely. After measurement, it was found that the metal catalyst remaining after combustion was about 30 wt% of the original weight of the carbon nanotube substrate. The nineteenth figure is a thermogravimetric analysis of the carbon nanotubes after microwave digestion. It can be seen from the drawing that the weight of the substrate sample reduced at 30 ° C to 450 ° C is very slow. It is the loss of moisture and non-crystalline carbon; the temperature is obviously reduced in the temperature range of 45CTC to 650 °C (that is, the multi-layer tube carbon nanotubes completely disappear at around 650 °C), and it is found after combustion. The remaining metal catalyst is only about 5.25 wt% of the original weight of the carbon nanotube substrate. This proves that the microwave digestion method is an effective purification method for multi-layer tube-walled carbon nanotubes, and it is an excellent and accurate method to estimate the weight percentage of purified multi-walled nanotube carbon nanotubes by using a thermogravimetric analysis system. 3. Differences in Raman spectroscopy before and after microwave digestion: From the twelfth figure, it can be seen that the intensity of D wave in the multi-layered carbon nanotubes without microwave digestion is larger than the number of G waves. The structure of amorphous carbon in the multi-layered nanocarbon 22 1247047 tube before purification is more; in the twentieth figure, the D wave number of the purified multi-layer carbon nanotubes is lower than the G wave number. From this, it can be proved that the purity of the multilayer carbon nanotube can be improved by microwave digestion. Through the above description and data comparison before and after purification, it can be confirmed that the present invention utilizes a microwave digestion system for purification treatment to obtain a high-yield multilayer tube-walled carbon nanotube. In the microwave system, nitric acid (HN〇3) and hydrochloric acid (HC1) quickly absorb microwave heat and completely dissolve the metal catalyst. The purification process not only does not destroy the carbon nanotubes, but also achieves high-quality carbon nanotubes. . In the microwave assisted and acid treatment system, the metal components in the multi-layer tube carbon nanotubes are dissolved, and the two-stage microwave digestion process can be completed in about one hour, and the purification time can be reduced to improve the processing efficiency. After purification, the metal catalyst in the substrate sample was reduced from the original 30 wt% to 5.15 wt%. The results show that the wall of the multi-layer tube-walled carbon nanotubes is not destroyed and contains only about 5 wt% of metal. In other words, the microwave tube digestion method can effectively remove the metal catalyst remaining in the carbon nanotubes to purify the multilayer tube wall carbon nanotubes. Furthermore, the method provided by the present invention can be applied to a single-layer tube-walled carbon nanotube, in addition to being applicable to a multi-layer tube-walled carbon nanotube, and the microwave digestion-assisted acid treatment process is not different, and It can exert the same effect and obtain high-quality carbon nanotubes, which will be combined. It can be seen from the above description that the most important feature of the present invention is to accelerate the digestion and removal of the metal catalyst remaining in the nanotube by means of microwave and 23 1247047 hot-impregnated carbon nanotube substrate acid solution, as the type of acid solution used. The values, concentration, and microwave time, temperature, power, etc. are not absolutely limited. The values disclosed in this specification are only the preferred values used in the experimental process, and it is not excluded to use the same microwave heating digestion to remove the naphthalene. There are other possible combinations of values for the metal catalyst remaining in the carbon nanotubes, which are also included in the scope of the invention. In summary, the technical means disclosed in the "method of removing metal catalyst in carbon nanotubes by microwave digestion" can effectively solve the problem of conventional treatment methods and achieve high purity nanocarbon. In order to maintain the purpose and effectiveness of the tube wall, the integrity of the tube, and the shortening of the processing time, the invention is based on the creation of the technical idea of the natural law, and the invention is called the patent law, and the application is made according to law. Give a detailed examination and grant a patent, to the feeling of Dexin. The above is only the preferred embodiment of the present invention, and the scope of the patents of the present invention is not limited thereto, so the equivalent structural changes of the scope of the patent application of the present specification are included in the present invention. In the scope of patents. [Simple description of the diagram] The first figure shows a schematic diagram of a carbon-like allomorphic structure. 24 1247047 The second figure shows the structure of the carbon nanotubes. The third figure shows a two-dimensional schematic diagram of graphite. The fourth figure shows a schematic diagram of a single-walled tube wall carbon nanotube model. The fifth diagram is not intended to be an arc discharge device. The sixth figure shows a schematic diagram of a laser evaporation device. The seventh diagram shows a flow chart of the present invention. The eighth figure shows a schematic diagram of the MPCVD equipment. The ninth figure shows a schematic diagram of the ECRCVD equipment. The SEM image of the multi-layer tube-walled carbon nanotubes is shown in the tenth figure. Dijon—The figure shows a schematic diagram of the Raman spectrometer equipment. Figure 12 shows the Raman analysis of the multi-walled nanotube carbon nanotubes before purification. Figure 13 shows the microwave digestion system used in the present invention. Figure 14 shows the thermogravimetric analysis system used in the present invention. Figure 15 shows the 多层 diagram of a multi-layer tube-walled carbon nanotube before microwave digestion. Figure 16 shows the enthalpy of the multi-layer tube-walled carbon nanotubes purified by microwave digestion. Figure 17 shows the HRTEM of the multi-layer tube-walled carbon nanotubes purified by microwave digestion. Μ ° 25 1247047 Figure 18 shows the thermogravimetric analysis before microwave digestion. Figure 19 shows the thermogravimetric analysis after purification. Figure 20 shows the Raman analysis of the multi-walled nanotube carbon nanotubes after purification. [References] 1. R. Saito? G. Dresselhaus, MS Dresselhaus, u Physical properties of Carbon Nanotubes'', Imperial College Press, London, (1998) 2. N. Hamada, S. Sawada, A. Oshiyama, Phys · Rev· Lett·, 1992 68 1581 3. R. Saito, M. Fujita, G. Dresselhaus, MS Dresselhaus, Appl.

Phys. Leet., 1992 60 2204 4. P.G.Collins and P.Avouris5Sci. Amer. Dec.,62 ( 2000) 5. S.Iijima，Nature 354 56(1991) 6· H· W. Kroto, J. R. Heath，S. C. O’Brien，R· F. Curl，R. E. Smalley， Nature 318 (1985) 162 7. W. Z. Li, S. S. Xie5 L. X. Qian? B. H. Chang, B. S. Zou? W. Y. Zhou, R. A. Zhao, G. Wang, Science 274 (1996) 1701. 8. S.C. Tsang, P.J.F. Harris, M.L.H. Green, Nature 362(1993) 520. 9. T. Y .Ebbesen, P. M. Ajaya, F .H .Liou, H. Hiura, K. Tangaki, Nature 367(1997)519. 10. K. Tohji，H. Takahashi，Y. Shinoda，N. Shimizu, B. Jeyadevan，I. Matsuoka, Y. Saito, A.Kasuya, S. Ito, Y. Nishina, J. Phys. Chem. B 101(1997) 1974. 11. B. Liu, T. Wagberg, E. Olssen, R. Yang，H. Li, S. Zhang，H. Yang, G. Zou, B.Sundqvist, Chem. Phys. Lett. 321(2000)365. 12. K.B. Shelimov, R. O. Esenaliev, A. G. Rinzler, C. B. Huffman, R. E. Smalley, Chem. Phys. Lett. 282(1998) 429.. 13. J. M. Moon, K. H. An, Y. H. Lee, Y. S. Park, D. J. Bae, G. S. Park, J. Phys. Chem. B 105(2001) 5677. 14. D. Chattopadhyay, I. Galeska, F. Papadimitrakopoulos, Carbon 40 (2002) 985. 15. X. H. Chen, C. S. Chen, Q. Chen, F. Q. Cheng, G. Zhang, Z. Z. Chen, Materials Lett. 57(2002) 734.Phys. Leet., 1992 60 2204 4. PGCollins and P.Avouris5Sci. Amer. Dec., 62 (2000) 5. S.Iijima, Nature 354 56 (1991) 6· H. W. Kroto, JR Heath, SC O'Brien, R. F. Curl, RE Smalley, Nature 318 (1985) 162 7. WZ Li, SS Xie5 LX Qian? BH Chang, BS Zou? WY Zhou, RA Zhao, G. Wang, Science 274 (1996) 1701. 8. SC Tsang, PJF Harris, MLH Green, Nature 362 (1993) 520. 9. T. Y. Ebbesen, PM Ajaya, F.H. Liou, H. Hiura, K. Tangaki, Nature 367 (1997) 519. 10. K. Tohji, H. Takahashi, Y. Shinoda, N. Shimizu, B. Jeyadevan, I. Matsuoka, Y. Saito, A. Kasuya, S. Ito, Y. Nishina, J. Phys. Chem. B 101 (1997) 1974. 11. B. Liu, T. Wagberg, E. Olssen, R. Yang, H. Li, S. Zhang, H. Yang, G. Zou, B. Sundqvist, Chem. Phys. Lett 321 (2000) 365. 12. KB Shelimov, RO Esenaliev, AG Rinzler, CB Huffman, RE Smalley, Chem. Phys. Lett. 282 (1998) 429.. 13. JM Moon, KH An, YH Lee, YS Park , DJ Bae, GS Park, J. Phys. Chem. B 105 (2001) 5677. 14. D. Cha Ttopadhyay, I. Galeska, F. Papadimitrakopoulos, Carbon 40 (2002) 985. 15. X. H. Chen, C. S. Chen, Q. Chen, F. Q. Cheng, G. Zhang, Z. Z. Chen, Materials Lett. 57 (2002) 734.

Claims

!247〇47 十、申請專利範圍： 1 種以彳政波消化法去除奈米碳管中金屬觸媒之方法，係將奈米碳管基材置入酸性溶液中，再置入微波消化系統中進行微波消化處理，藉酸性溶液能夠迅速吸收微波的熱與能之作用，使經微波加熱之酸溶液，可以快速消化去除奈米碳管中殘留之金屬觸媒。 2、依據申請專利範圍第丄項所述以微波消化法去除不米石反s中金屬觸媒之方法’其中，該酸性溶液係确酸 (HN〇3)與鹽酸（HC1)的混合溶液。 3、依據中請專利範圍第2項所述—種以微波消化法去除奈㈣管中金屬觸媒之方法，其中，該雜與鹽酸的混合溶液的濃度為1 : 1。 4、依據申請專利範圍第i項所述以微波消化法去除奈米碳管巾金屬觸狀料，其巾，職㈣化系統之微波功率設定為100w。 5、依據申請專利範圍第1項所述以微波消化法去除奈米破管巾金屬觸狀方法，其巾，該微波消化系統之過程係分二階段進行。 6、依據申請專利範圍第5項所述以微波消化法去除奈米碳管中金屬觸媒之方法，其中，該微波消化系統過程 1247047 之第-階段微波消化處理係設定加熱2〇分鐘，使溫度上升至210°C。 7、依據申請專利範圍第5項所述以微波消化法去除. 不米石反官中金屬觸媒之方法，其中，該微波消化系統過程之第一階段微波消化處理係將溫度維持在21〇。匸並加熱3〇分鐘。 8、依據申請專利範圍第i項所述以微波消化法去除 _ 不米石反官中金屬觸媒之方法，其中，該奈米碳管置入酸性溶液再置入微波消化系統中進行微波消化後，會冷卻形成懸浮液體。 9、依據申請專利範圍第8項所述以微波消化法去除奈米碳管中金屬觸媒之方法，其中，該懸浮液體以去離子水 /月洗，再用 0· 1 μπι 聚四氟乙烯（p〇iytetraflu〇r〇ethyiene， PTFE)膜過濾’重複以去離子水清洗過濾至濾液澄清不含籲酸液。 10、依據申請專利範圍第g項所述以微波消化法去除 · 奈米碳管中金屬觸媒之方法，其中，該經微波消化處理及 . 經去離子水清洗後之奈米碳管，最後以乙醇清洗，待乾燥後即可得純化之奈米碳管基材。 11、一種以微波消化法去除奈米碳管中金屬觸媒之方 28 1247047 法，係將奈米碳管基材置入1 : 1混合的硝酸（hn〇3 )與鹽酸（HC1)溶液中，再置入微波消化系統中，分二階段進行微波消化處理，藉硝酸與鹽酸能夠迅速吸收微波的熱與月b之作用，使經微波加熱之硝酸與鹽酸之溶液可以快速消化去除奈米碳管中殘留之金屬觸媒，並於冷卻後形成懸浮液體，然後將懸浮液體以去離子水清洗，再用〇1μιη聚四氟乙烯（Polytetrafluoroethylene，PTFE)膜過濾，重複以去離子水清洗過濾至濾液澄清不含酸液，再將奈米碳管基材以乙醇清洗，待乾燥後，即可得純化之奈米碳管基材。 12、依據申請專利範圍第11項所述以微波消化法去除奈米碳管中金屬觸媒之方法，其中，該微波消化系統過私之第ϋ微波消化處理係設定加熱π分鐘，使溫度上升至21(TC。 13、依據申請專㈣圍第11項所述以微波消化法去除奈米礙管巾金屬觸媒之方法，其巾，該微波消化系統過程之第二階段微波消化處理係將溫度維持在2賊並加熱 30分鐘。 14依據申5月專利範圍第^項所述以微波消化法去 It'&中金屬觸媒之方法中，該微波消化系統之微波功率設定為100W。!247〇47 X. Patent application scope: 1 method for removing metal catalyst in carbon nanotubes by 彳政波 digestion method, placing the carbon nanotube substrate in an acidic solution and then placing it into the microwave digestion system In the microwave digestion treatment, the acidic solution can quickly absorb the heat and energy of the microwave, so that the microwave heated acid solution can quickly digest and remove the residual metal catalyst in the carbon nanotubes. 2. A method for removing a metal catalyst in a non-meterite anti-s by microwave digestion according to the scope of the patent application, wherein the acidic solution is a mixed solution of acid (HN〇3) and hydrochloric acid (HC1). 3. The method for removing the metal catalyst in the naphthalene tube by microwave digestion according to the second item of the patent scope, wherein the concentration of the mixed solution of the hetero and hydrochloric acid is 1:1. 4. The nano-carbon tube towel metal contact material is removed by microwave digestion according to the item i of the patent application scope, and the microwave power of the towel (4) system is set to 100w. 5. The method for removing the metal touch of the nano tube by the microwave digestion method according to the first item of the patent application scope, the towel, the process of the microwave digestion system is carried out in two stages. 6. The method for removing a metal catalyst in a carbon nanotube by microwave digestion according to the fifth aspect of the patent application, wherein the microwave digestion process of the microwave digestion system 1247047 is set to be heated for 2 minutes, so that The temperature rose to 210 °C. 7. The method of removing the metal catalyst in the anti-official state by microwave digestion according to the fifth aspect of the patent application scope, wherein the microwave digestion treatment of the first stage of the microwave digestion system maintains the temperature at 21〇. . Knead and heat for 3 minutes. 8. The method for removing the metal catalyst in the anti-official stone by microwave digestion according to the item i of the patent application scope, wherein the carbon nanotube is placed in an acidic solution and then placed in a microwave digestion system for microwave digestion. After that, it will cool to form a suspended liquid. 9. A method for removing a metal catalyst in a carbon nanotube by microwave digestion according to item 8 of the patent application scope, wherein the suspension liquid is washed with deionized water/month, and then with 0·1 μπι polytetrafluoroethylene. (p〇iytetraflu〇r〇ethyiene, PTFE) Membrane filtration 'Repeat and filter with deionized water until the filtrate is clear and free of acid. 10. The method for removing the metal catalyst in the carbon nanotube by microwave digestion according to the g-g of the patent application scope, wherein the microwave digestion process and the carbon nanotube after the deionized water cleaning, finally It is washed with ethanol and dried to obtain a purified carbon nanotube substrate. 11. A method for removing a metal catalyst in a carbon nanotube by microwave digestion 28 1247047, placing a carbon nanotube substrate in a 1: 1 mixed solution of nitric acid (hn〇3) and hydrochloric acid (HC1) Then, it is placed in the microwave digestion system, and the microwave digestion process is carried out in two stages. The nitric acid and hydrochloric acid can quickly absorb the heat of the microwave and the role of the moon b, so that the solution of the nitric acid and hydrochloric acid heated by the microwave can be rapidly digested to remove the nano carbon. The metal catalyst remaining in the tube is cooled to form a suspension liquid, and then the suspension liquid is washed with deionized water, filtered with a μ1μη polytetrafluoroethylene (PTFE) membrane, and repeatedly filtered with deionized water to filter. The filtrate is clarified to be free of acid, and the carbon nanotube substrate is washed with ethanol. After drying, a purified carbon nanotube substrate can be obtained. 12. The method for removing a metal catalyst in a carbon nanotube by microwave digestion according to the eleventh application patent scope, wherein the microwave digestion system of the microwave digestion system is set to be heated for π minutes to increase the temperature. To 21 (TC. 13. According to the application (4), according to the 11th item, the method of removing the metal catalyst of the nanometer tube by microwave digestion, the towel, the second stage of the microwave digestion process of the microwave digestion system will be The temperature is maintained at 2 thieves and heated for 30 minutes. 14 In the method of microwave digestion to the It's & Metallic Catalyst according to the method of the May patent scope, the microwave power of the microwave digestion system is set to 100W.