【作者】 王国瑞；

【导师】 莫尊理；

【作者基本信息】 西北师范大学 ， 无机化学， 2010， 硕士

【摘要】 近年来碳纳米管的功能化成为纳米领域一大研究热点。通过对碳纳米管进行功能化，使其在某些溶液环境或者纳米复合材料中的分散度得到明显改善，并且为碳纳米管的分离或提纯提供了更为有利的条件。碳纳米管的功能化研究已逐步发展成为制备具有某些特定功能的碳纳米管及其复合材料的手段。功能化后的碳纳米管不仅保持了原有的特异性质，而且还表现出修饰基团参加反应的活性，为碳纳米管的分散、组装及表面反应提供了可能，从而引起了科学家的极大兴趣，也使得碳纳米管在纳米材料的舞台上更加活跃。本文运用分子模拟的方法来研究手性分子非共价修饰单壁碳纳米管的微观结构、界面作用以及热学性能，主要研究内容包括以下三个部分：1.以联萘及其衍生物为核，以亚苯基为重复单元，1-3代的手性树状分子以及碳纳米管模型的建立与结构优化。研究了单壁碳纳米管与手性树状分子G0-G2之间的相互作用，通过能量分析，温度的影响和RDF分析得出以下结论：它们之间存在着强的非键作用能，这与G0-G2都具有数量不等的芳香环，发生包裹行为时可能与碳纳米管侧壁的π电子体系发生π–π作用有关，这种相互作用使得碳纳米管与树状分子之间的结合能增强。并且研究了温度的影响，温度对单壁碳纳米管和G0之间的相互作用影响较小，而单壁碳管和G1、G2之间的相互作用随着温度的升高有着明显的减小。分析了三个复合体系的径向分布函数，说明单壁碳纳米管和手性树状分子能通过非键相互作用而有效的结合。理论上用手性分子非共价功能化单壁碳纳米管，为制成高灵敏性的手性荧光传感器提供了理论依据。2.用分子动力学模拟L-色氨酸(Try)非共价修饰到单壁碳纳米管(SWNT)，研究其相互作用，理论上实现L-色氨酸(Try)非共价功能化单壁碳纳米管。利用分子动力学计算了200ps内两组份之间的相互作用，发现复合体系在整个模拟时间内的过程是一个能量逐渐降低并且逐渐达到稳定结构的过程，也说明复合体系中单壁碳纳米管和L-色氨酸之间能通过相互作用而复合。单壁碳纳米管和L-色氨酸的结合能除了有π–π相互作用以外，还存在范德华力和静电作用能，在498K时结合能最低，复合体系相对稳定。3.将L-酪氨酸(Tyr)非共价修饰到单壁碳纳米管(SWNT)上，利用分子动力学计算了200ps内两组份之间的相互作用，发现复合体系在整个模拟时间内的过程是一个能量逐渐降低并且逐渐达到稳定结构的过程，也说明复合体系中单壁碳纳米管和L-酪氨酸之间能通过相互作用而复合。分析了从298K到598K之间复合体系的能量变化，发现不同温度下结合能均为负值，表明两者之间存在着强的相互作用能，说明单壁碳纳米管和L-酪氨酸的结合能除了有π–π相互作用以外，也存在较强的范德华能来相互作用，也存在一定的静电能。在373k时复合体系有相对稳定的结构。最后通过对L-色氨酸和L-酪氨酸功能化单壁碳纳米管模拟结果进行对比，发现L-色氨酸与单壁碳纳米管复合体系有更低的结合能，更稳定的结构，并且非键作用主要为范德华力，其次为静电力。预期利用氨基酸的手性特点再与碳纳米管的独特特性结合，应用到手性物质的分离、识别、测定等方面。这对于拓展碳纳米管在分离识别领域的研究具有重要的意义。更多还原

【Abstract】 The functionlization of carbon nanotube(CNT) has become the study hotspot recently.The CNT distribution in the nanocomposites or some solution environment has beenimproved by the functionlization, and provide the favorable condition for CNT to separateor purify.The study of functionlization of the CNT has gradually developed the method toprepare the specified functional CNT and composite. The functional CNT not only keepthe original special nature, but aslo put up the adorn radical activity in the reaction, andprovide the possibility for CNT to disperse, assemble and surface reaction, and thereforeto arouse the enormous interest of the scientists, and made the CNT more active in thestage of the nanophase materials.The article studied the sub atomic structure, interface action and heat function of chiralmolecular nonfunctionlization of the CNT by the molecular simulation, the main contentcontains the three section:1. The simulated chiral dendrimers (G0,G1 and G2) were binaphthyl cored-basedchiral phenylene dendrimers and single wall carbon nanotube(SWNT), the the modelswere constructed and optimized. The interaction between the chiral dendrimers andSWNT were studied, the conclusion was obtained by the energy analysis, temperatureeffect and RDF analysis: strong nonbond energy was exist, which related to the differentphenylene rings of G0-G2, the interaction made the binding energy of SWNT anddendrimers increased, but the interaction of SWNT and G1 and G2 strongly decreased asthe temperature increase. By the analysis the RDF of the three composite, we know thatSWNT can effectively jion with G0-G2 by nonbond interaction. Theoreticallydemonstrated the possibility of nocovalent functionalization of SWNT with chiraldendrimers, which can be used to produce nanocomposites such as highly sensitive aswell as enantioselective fluorescent sensors.2. Molecular dynamic simulation was used to the noncovalent functionlization ofSWNT with the tryptophan, study their interaction, theoretically demonstrated thepossibility of nocovalent functionalization of SWNT. Calculate the two’s interaction in200ps with molecular dynamics, and find that the whole simulation process was that theenergy gradually decreased and finally got the stable stucture,aslo demonstrated thatSWNT and tryptophan in the composite could combined with interaction, and the interaction was mainly theπ–πinteraction, beside the vdw and electrostatic, and thecomposite has the lowest interaction at 498K, the conposite absolutely stable.3. Select the tyrosine to nonfunctionlize SWNT, calculate the two componets’interaction with the molecular dynamics, the results was that the composites’energygradually decreased to get the stable structure in the process, aslo demonstrated they couldinteract with each other. By the analysis of the energy evolution from 298K to 598K in thecomposite, find that the interaction were all negative at different temperature,denmonstrated that the two have the stronginteraction, which was mainly theπ–πinteraction, the vdw and electrostatic, the composite has absolutely stable structure at373K. And finally, by the comparation of the simulated results, we find that the compositeof SWNT and the tryptophan has lower interaction to gain more stable structure, and theinteraction mainly caused by the vdw and electrostatic. We respected to use the chiralfunction of tryptophan and tyrosine join with SWNT’s special function, may be used in thesepration, recognization and mesurement of the chiral substance, which was important todevelop SWNT in the seperation study.更多还原