【作者】 宋桂玲；

【导师】 高勇；

【作者基本信息】 湘潭大学 ， 高分子化学与物理， 2010， 硕士

【摘要】 碳纳米管(CNTs)化学修饰可提高其在溶剂中的溶解性,有利于其性能的发挥,进一步扩大其在实际中的应用。本论文采用聚合物及β-环糊精(β-CD)对单壁碳纳米管(SWCNTs)进行化学修饰,并将β-CD功能化的SWCNTs用于修饰玻碳电极(GCE),修饰后的GCE用来研究某些生物分子的电化学行为,并在此基础上建立它们的分析检测方法。聚合物共价修饰SWCNTs。通过混酸对SWCNTs氧化后与乙二醇反应得到羟基修饰的SWCNTs,然后再与丙烯酰氯反应,从而将可聚合双键基团引入到SWCNTs表面,得到乙烯基修饰的SWCNTs;接着以十二烷基苯磺酸钠(SDBS)为乳化剂,偶氮二异丁腈(AIBN)为引发剂,采用乳液聚合方法将聚甲基丙烯酸甲酯(PMMA)接枝到SWCNTs表面。详细研究了预乳化时间对表面接枝聚合物含量高低的影响。溶解度实验显示聚合物共价修饰后增强了SWCNTs在溶剂中的溶解性。采用红外光谱(FTIR)、拉曼光谱(Raman)、透射电子显微镜(TEM)对聚合物修饰的SWCNTs进行了结构分析。Raman测试结果表明聚合物共价接枝到SWCNTs表面,TEM分析结果表明聚合物存在于SWCNTs的侧壁和开口端。热失重分析(TGA)结果表明,在其它条件相同时,SWCNTs表面接枝聚合物含量随着预乳化时间的延长而增加。β-CD功能化SWCNTs修饰GCE及其在电化学中应用研究。先采用混酸氧化SWCNTs,表面产生的羧基进一步转化为酰氯,然后与氨基化的β-CD反应,从而在SWCNTs表面引入β-CD,并将β-CD共价键修饰的SWCNTs用于修饰GCE。以抗坏血酸(AA)、尿酸(UA)混合体系为研究对象,采用循环伏安(CA)法对AA、UA的电化学行为进行研究。具体考查了溶液pH值,扫描速率,底物浓度及干扰离子等实验条件改变对AA、UA电化学行为的影响。结果显示,相比较裸GCE,β-CD共价键修饰SWCNTs改性的GCE结合了SWCNTs优良的电化学催化性能及β-CD对某些客体化合物的包结能力,修饰电极具有较高的灵敏度。与β-CD非共价键分散SWCNTs修饰GCE相比,该方法可克服高浓度β-CD在CNTs表面形成膜阻碍电活性底物在电极表面扩散的缺点,提高分析电极的灵敏度,降低了电化学电位。更多还原

【Abstract】 The current research involved covalent functionalization of single-wall carbon nanotubes (SWCNTs) and its application in the field of electrochemical analysis. The following two aspects were included.Covalent functionalization of SWCNTs with polymer was accomplished by emulsion polymerization using sodium dodecylbenzene sulfonate (SDBS) as emulsifying agent. The polymerizable vinyl groups were incoperated on SWCNTs surfaces by successive chemical reaction process, including oxidation, hydroxylation, and vinylation reactions. The as-prepared vinylated SWCNTs were then dispersed in water in the presence of SDBS, resulting in the exfoliation of SWCNT bundles into individual SWCNTs and formation of SWCNT micelles simultaneously. Subsequent addition of methyl methacrylate (MMA) resulted in its absorption into the formed SWCNT micelles due to the interactions between the monomer and the tube surface functionalities. Grafting copolymerization of MMA with vinyl groups on the SWCNT surface was thus performed in the micelles to produce poly(methyl methacrylate) (PMMA) functionalized SWCNTs. Thermogravimetric analysis (TGA) indicated that the average polymer content in the functionalized SWCNTs ranged from 42 wt% to 63 wt%, depending on the pre-emulsion time of monomer. Further characterization was accomplished by transmission electron microscopy (TEM), which was utilized to image SDBS exfoliated SWCNTs and polymer-functionalized SWCNTs.Carbon nanotubes have been increasingly used in electrochemical analysis because of their excellent electrical conductivity and good catalytic activity. A new electrochemical sensor combined with the excellent electrochemical properties of SWCNTs and the recognition ability ofβ-cyclodextrin (β-CD) to guest molecule was fabricated in this paper. Firstly,β-CD was covalently incorporated on the surface of SWCNTs through the reaction of carboxylic chloride groups on the SWCNTs surface with mono-6-(hexanediamino)-β-cyclodextrin (HDA-β-CD), resulting inβ-CD functionalized SWCNTs (SWCNT-β-CD). Subsequently, SWCNT-β-CD modified glassy-carbon electrode (GCE) was constructed by dropping SWCNT-β-CD suspension onto the GCE. The modified GCE was used to simultaneously determine the mixture of ascorbic acid (AA) and uric acid (UA). The electrochemical behaviors of AA and UA were investigated by cyclic voltammetry (CV). The results demonstrated that SWCNT-β-CD modified GCE could discriminately determine AA and UA with their respective oxidation peaks. An enhanced analytical performance was obtained compared with non-modified GCE.更多还原