论文标题:碳纳米管对苯胺的吸附研究
The Study of Aniline Adsorption on Carbon Nanotubes
论文作者 耿成怀
论文导师 成荣明,论文学位 硕士,论文专业 分析化学
论文单位 华东师范大学,点击次数 68,论文页数 65页File Size2588k
2004-05-01论文网 http://www.lw23.com/lunwen_396350687/ 碳纳米管;苯胺;吸附;比表面;孔容;孔径分布;吸附等温式;热力学;动力学;机理
Carbon nanotubes, Aniline, Adsorption, Surface area, Pore volume, Pore size distribution, Adsorption isotherms, Thermodynamics, Kinetics, Mechanism
碳纳米管作为一种新型的纳米材料，由于其独特的物理化学性能以及在众多领域的潜在应用背景，自发现以来便吸引了世界各国科学家的广泛重视，成为纳米材料领域研究的一个新热点。本文主要进行了以下几方面的研究： 1、碳纳米管的纯化及其表征 在本文中，使用加热焙烧法和硝酸回流法对催化裂解化学气相沉积法制备的碳纳米管进行纯化处理，然后使用扫描电镜、FT—IR光谱分析仪、吸附分析仪对碳纳米管的形貌、表面官能团、比表面积、孔容、孔径分布等方面进行了研究。 2、碳纳米管对苯胺的吸附 不同性质的碳纳米管对苯胺有不同的吸附速率和吸附量，碳纳米管原料有最大的吸附速率；碳纳米管B有最大的吸附量。在吸附条件相同的情况下，溶质的溶解度越小，吸附量越大。温度对吸附有比较明显的影响，温度越高，吸附量越小。在溶液的PH值为5时，碳纳米管B对苯胺有最大的吸附量。氯化钾的存在能够增大碳纳米管对苯胺的吸附量，随着氯化钾浓度的增加，吸附量会出现最大值，此后增加氯化钾的浓度，吸附量反而降低。使用过的碳纳米管经过简单处理后可以再生。 3、碳纳米管吸附苯胺的吸附热力学、动力学及其吸附机理 通过吸附等温式的拟合发现，碳纳米管原料对苯胺的吸附对Freundlich公式有最佳的拟合结果。吸附热力学的计算表明，碳纳米管对苯胺的吸附是放热、熵减少的自发过程。此过程服从Lagergren一级动力学方程。碳纳米管原料和碳纳米管A对苯胺的吸附主要是疏水键力和范德华力，碳纳米管B除了上述作用外还有氢键作用和酸碱作用。
Carbon nanotubes ,as a typical representative of nanomaterial ,have drawnwidespread attention since their discovery because of their distinctive physical andchemical properties and promising application in many fields. Now carbon nanotubeshave been one of the hotspots in the nanomaterial field. This paper mainly includesthree parts as follows:Part one: Purification of carbon nanotubes and determination of their surfacecharacteristicsCarbon nanotubes ,which were produced by catalytic chemical-vapour deposition, were purified by heating or refluxing with nitric acid respectively. Their physicochemical properties were investigated by SEM, FT-IR and BET N2 adsorption. Part two: Aniline adsorption on carbon nanotubesThe adsorption volume and rate change a lot on different carbon nanotubes . As-grown carbon nanotubes reached adsorption equilibrium in the shortest time ,but carbon nanotubes B had the largest adsorption volume .The less the solubility is ,the larger the adsorption volume can be acquired. The adsorption capacity decreased with the increase of temperature. The adsorption capacity enhanced with KC1 concentration from 0.1 to 0.7M. Further increase in the salt concentration reduced the adsorption capacity. Carbon nanotubes can be regenerated after simple treatment. Part three: Thermodynamics, Kinetics and Mechanism of aniline adsorption on carbon nanotubesThe results show that the adsorption isotherm confirms to the Freundlich equation, and the adsorption is a spontaneous ,exothermal and decreasing entropy process. The adsorption obeys the first-order kinetic equation-Lagergren mode. The forces between aniline and as-grown carbon nanotubes ,carbon nanotubes A are mainly Van Der Waals force and hydrophobic interaction. Besides above forces ,there are hydrogen-bonding and acid-base interaction between aniline andcarbon nanotubes B.
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