化學(xué)氣相沉積法制備分枝狀碳納米管及其復(fù)合材料的研究
發(fā)布時間：2018-11-28 21:14
【摘要】： 碳納米管由于其獨特的物理化學(xué)性能和潛在應(yīng)用價值,引起了科學(xué)界廣泛關(guān)注。本文研究了以二甲硫醚為碳源,以Co/MgO為催化劑,采用化學(xué)氣相沉積法制備碳納米管的方法;探究各種實驗參數(shù),如反應(yīng)溫度、氣體流量等因素對碳納米管生長過程的影響;系統(tǒng)地研究了分枝狀碳納米管的形核及生長機制,實現(xiàn)了分枝狀碳納米管的可控制備;研究了二甲硫醚的濃度對Co_9S_8納米線填充碳納米管產(chǎn)物的形貌和結(jié)構(gòu)的影響以及填充機理,發(fā)現(xiàn)了工藝簡單、反應(yīng)可控性較好的Co_9S_8納米線填充碳納米管的制備方法。主要研究結(jié)果如下: 1.采用催化裂解二甲硫醚制備了碳納米管,實驗發(fā)現(xiàn)產(chǎn)物對溫度很敏感,通過對比實驗發(fā)現(xiàn)合適的反應(yīng)溫度為1000°C;二甲硫醚蒸汽的濃度和流量對產(chǎn)物的產(chǎn)量和形貌也有很大影響,當(dāng)二甲硫醚的濃度很高時,大量的碳原子覆蓋在催化劑的表面,導(dǎo)致催化劑的活性降低,此時產(chǎn)物為很短的碳納米管或碳納米纖維,且其石墨化程度很低,而當(dāng)二甲硫醚的濃度較低時,產(chǎn)物比較少且石墨化程度也很低。碳納米管生長的最佳二甲硫醚濃度范圍為:3.36-5.48%。二甲硫醚流量較大時有大量分枝狀碳納米管生成,這些分枝狀碳納米管有很長的分支,在納米器件領(lǐng)域有很大的應(yīng)用潛力,而當(dāng)二甲硫醚流量較小時,產(chǎn)物較少。對分枝狀碳納米管的生長機理也進(jìn)行了研究,并提出了一個簡單的生長模型。 2.采用化學(xué)氣相沉積法制備出了碳納米管及Y形碳納米管產(chǎn)物,碳納米管直徑分布在30~70nm范圍內(nèi),其中Y形碳納米管外徑約為60~70nm,內(nèi)徑約為30~40nm。通過SEM、TEM、Raman、XRD對產(chǎn)品的形態(tài)與結(jié)構(gòu)進(jìn)行表征分析,結(jié)果顯示所制得碳納米管石墨化程度比較高,產(chǎn)品純度也較高。對單根Y形碳納米管的三個分支的導(dǎo)電性能進(jìn)行了測試,結(jié)果表明所測試的Y形碳納米管具有類似于金屬性的導(dǎo)電性能。 3.制得了Co_9S_8納米線填充碳納米管,影響Co_9S_8納米線填充碳納米管的關(guān)鍵因素為二甲硫醚的濃度,二甲硫醚不但提供碳源,也提供Co_9S_8填充碳納米管過程中必不可少的硫源。實現(xiàn)Co_9S_8納米線填充碳納米管的二甲硫醚最佳濃度范圍為1.26%-1.47%。當(dāng)二甲硫醚的濃度高于1.47%時,產(chǎn)物中有Y形碳納米管生成;二甲硫醚濃度低于1.26%時,產(chǎn)物為中空的短碳納米管。Co_9S_8納米線填充碳納米管的生長機制為“催化劑原位轉(zhuǎn)變誘導(dǎo)碳納米管填充”。
[Abstract]:Carbon nanotubes (CNTs) have attracted wide attention due to their unique physical and chemical properties and potential application value. In this paper, the method of preparing carbon nanotubes by chemical vapor deposition with dimethyl sulfide as carbon source and Co/MgO as catalyst was studied, and the effects of various experimental parameters, such as reaction temperature and gas flow rate, on the growth process of carbon nanotubes were investigated. The nucleation and growth mechanism of branched carbon nanotubes (CNTs) were studied systematically, and the controllable preparation of branched CNTs was realized. The effect of the concentration of dimethyl sulfide on the morphology and structure of carbon nanotubes filled with Co_9S_8 nanowires and the filling mechanism were studied. Preparation of Co_9S_8 nanowires filled with carbon nanotubes with good controllability. The main results are as follows: 1. Carbon nanotubes (CNTs) were prepared by catalytic pyrolysis of dimethyl sulfide. The results showed that the product was sensitive to temperature and the appropriate reaction temperature was 1000 擄C by comparison. The concentration and flow rate of dimethyl sulfide vapor also have a great influence on the yield and morphology of the product. When the concentration of dimethyl sulfide is very high, a large number of carbon atoms cover the surface of the catalyst, which results in the decrease of catalyst activity. The products are short carbon nanotubes or carbon nanofibers, and their graphitization degree is very low, but when the concentration of dimethyl sulfide is lower, the products are less and the degree of graphitization is very low. The optimum concentration range of dimethyl sulfide for carbon nanotube growth is 3.36-5.48. A large number of branched carbon nanotubes are formed when the flow rate of dimethyl sulfide is high. These branched carbon nanotubes have long branching and have great application potential in the field of nanodevices. However, when the flow rate of dimethyl sulfide is small, the products are less. The growth mechanism of branched carbon nanotubes was also studied and a simple growth model was proposed. 2. Carbon nanotubes (CNTs) and Y-shaped carbon nanotubes (CNTs) were prepared by chemical vapor deposition (CVD). The diameter of carbon nanotubes (CNTs) was distributed in the range of 30~70nm. The outer diameters of Y-shaped CNTs and the inner diameters of Y-shaped CNTs were about 607nmand 304nmrespectively. The morphology and structure of the products were characterized by SEM,TEM,Raman,XRD. The results showed that the graphitization degree of the carbon nanotubes was high and the purity of the products was also high. The electrical conductivity of three branches of a single Y-shaped carbon nanotube is tested. The results show that the Y-shaped carbon nanotube has a similar electrical conductivity to that of gold. 3. Carbon nanotubes filled with Co_9S_8 nanowires were prepared. The key factor affecting Co_9S_8 nanowires filling carbon nanotubes was the concentration of dimethyl sulfide, which not only provided carbon source, It also provides an essential sulfur source for Co_9S_8 filled carbon nanotubes. The optimum concentration range of Co_9S_8 nanowire filled carbon nanotubes is 1.26-1.47. When the concentration of dimethyl sulfide is higher than 1.47, Y-shaped carbon nanotubes are formed in the product. When the concentration of dimethyl sulfide is lower than 1.26, the product is hollow short carbon nanotubes. The growth mechanism of Co_9S_8 nanowires filled carbon nanotubes is "catalyst in-situ transformation induces carbon nanotubes filling".
【學(xué)位授予單位】：太原理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2010
【分類號】：TB383.1
本文編號：2364266
[Abstract]:Carbon nanotubes (CNTs) have attracted wide attention due to their unique physical and chemical properties and potential application value. In this paper, the method of preparing carbon nanotubes by chemical vapor deposition with dimethyl sulfide as carbon source and Co/MgO as catalyst was studied, and the effects of various experimental parameters, such as reaction temperature and gas flow rate, on the growth process of carbon nanotubes were investigated. The nucleation and growth mechanism of branched carbon nanotubes (CNTs) were studied systematically, and the controllable preparation of branched CNTs was realized. The effect of the concentration of dimethyl sulfide on the morphology and structure of carbon nanotubes filled with Co_9S_8 nanowires and the filling mechanism were studied. Preparation of Co_9S_8 nanowires filled with carbon nanotubes with good controllability. The main results are as follows: 1. Carbon nanotubes (CNTs) were prepared by catalytic pyrolysis of dimethyl sulfide. The results showed that the product was sensitive to temperature and the appropriate reaction temperature was 1000 擄C by comparison. The concentration and flow rate of dimethyl sulfide vapor also have a great influence on the yield and morphology of the product. When the concentration of dimethyl sulfide is very high, a large number of carbon atoms cover the surface of the catalyst, which results in the decrease of catalyst activity. The products are short carbon nanotubes or carbon nanofibers, and their graphitization degree is very low, but when the concentration of dimethyl sulfide is lower, the products are less and the degree of graphitization is very low. The optimum concentration range of dimethyl sulfide for carbon nanotube growth is 3.36-5.48. A large number of branched carbon nanotubes are formed when the flow rate of dimethyl sulfide is high. These branched carbon nanotubes have long branching and have great application potential in the field of nanodevices. However, when the flow rate of dimethyl sulfide is small, the products are less. The growth mechanism of branched carbon nanotubes was also studied and a simple growth model was proposed. 2. Carbon nanotubes (CNTs) and Y-shaped carbon nanotubes (CNTs) were prepared by chemical vapor deposition (CVD). The diameter of carbon nanotubes (CNTs) was distributed in the range of 30~70nm. The outer diameters of Y-shaped CNTs and the inner diameters of Y-shaped CNTs were about 607nmand 304nmrespectively. The morphology and structure of the products were characterized by SEM,TEM,Raman,XRD. The results showed that the graphitization degree of the carbon nanotubes was high and the purity of the products was also high. The electrical conductivity of three branches of a single Y-shaped carbon nanotube is tested. The results show that the Y-shaped carbon nanotube has a similar electrical conductivity to that of gold. 3. Carbon nanotubes filled with Co_9S_8 nanowires were prepared. The key factor affecting Co_9S_8 nanowires filling carbon nanotubes was the concentration of dimethyl sulfide, which not only provided carbon source, It also provides an essential sulfur source for Co_9S_8 filled carbon nanotubes. The optimum concentration range of Co_9S_8 nanowire filled carbon nanotubes is 1.26-1.47. When the concentration of dimethyl sulfide is higher than 1.47, Y-shaped carbon nanotubes are formed in the product. When the concentration of dimethyl sulfide is lower than 1.26, the product is hollow short carbon nanotubes. The growth mechanism of Co_9S_8 nanowires filled carbon nanotubes is "catalyst in-situ transformation induces carbon nanotubes filling".
【學(xué)位授予單位】：太原理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2010
【分類號】：TB383.1
【參考文獻(xiàn)】
相關(guān)期刊論文 前2條
1 張繼紅，魏秉慶，梁吉，高志棟，吳德海;激光熔覆巴基管／球墨鑄鐵的研究[J];金屬學(xué)報;1996年09期
2 高永剛,施興華,趙亞溥;碳納米管的力學(xué)行為[J];機械強度;2001年04期
，本文編號：2364266
本文鏈接：http://sikaile.net/shekelunwen/minzhuminquanlunwen/2364266.html
最近更新
教材專著
