【作者】 何侃；

【导师】 邱介山；

【作者基本信息】 大连理工大学 ， 化学工艺， 2010， 硕士

【摘要】 碳纳米管(CNTs),因其存在优异的物理和化学性能而备受关注。近年来,通过对碳纳米管进行适当修饰,然后将其应用到生物学领域成为新的研究热点。本文系统的研究了对碳纳米管的化学修饰,通过对碳纳米管的多步反应成功将柠檬酸、壳聚糖和亚铁离子逐步关联到碳纳米管的表面,对其进行FT-IR、UV-Vis、SEM、TEM、XRD和TGA等表征,并对其在生物学领域的潜在应用进行了研究。目前,对碳纳米管的化学修饰主要集中在氧化处理碳纳米管基础上,利用二氯亚砜对碳纳米管酰氯化,但是此方法工艺复杂、具有生物毒害性。本文利用柠檬酸来修饰氧化后的碳纳米管(CA-CNTs)。研究表明,柠檬酸通过酯化反应关联到碳纳米管的表面上,丰富了碳纳米管表面的含氧官能团,特别是羧基官能团。其表面含氧官能团占总量的7%(wt)。同时,经柠檬酸修饰后,碳纳米管相互缠绕现象得到进一步缓解,并降低了其表面电负性,增大其亲水性,有利于其在水中的分散。当柠檬酸比例为7：1时,柠檬酸修饰氧化碳纳米管的Zeta电位达到最小,为-42.6 mV。柠檬酸修饰氧化碳纳米管,提高了其表面活性,有利于后续反应的进行。通过研究壳聚糖共价接枝交联在柠檬酸修饰氧化碳纳米管,制备壳聚糖／柠檬酸修饰碳纳米管复合材料(CTS/CA-CNTs)。研究表明,壳聚糖通过酰胺键关联到碳纳米管表面上使得柠檬酸修饰氧化碳纳米管的物相结构发生变化,碳纳米管的石墨化峰降低,当壳聚糖比例达到7：1时,其石墨化峰几乎消失,此时壳聚糖包覆在碳纳米管上形成复合膜,壳聚糖约占总量的55%(wt)。同时,壳聚糖／柠檬酸修饰碳纳米管复合材料对葡萄糖氧化酶有良好的吸附性能,表明其在生物传感器领域具有潜在应用。通过研究利用壳聚糖／柠檬酸修饰碳纳米管吸附亚铁离子,制备亚铁-壳聚糖／柠檬酸修饰碳纳米管复合材料(Fe2+-CTS/CA-CNTs)。研究表明,壳聚糖／柠檬酸修饰碳纳米管通过壳聚糖的-NH2配位吸附亚铁离子,亚铁离子的最大担载量为3.394%(wt)。其具有超顺磁性,最大Ms为2.57 emu／g,远优于Gadonanotube的磁性,表明其在MRI领域具有潜在的应用。更多还原

【Abstract】 Recently, as a novel nano material, carbon nanotubes (CNTs) have attracted great attention in the biology fields due to their unique physical and chemical properties. In this thesis, the chemical modifications of CNTs have been investigated. Citric acid (CA), chitosan (CTS) and ferrous ions (Fe2+) associated with the surface cf carbon nanotubes step by step by mutli-step reactions. And they were examined using FT-IR, UV-Vis, SEM, TEM, XRD and TGA. Further more, their potential applications in biology have been discussed.Currently, the chemical modification of CNTs mainly concentrates on the acylation process by thionyl chloride after the oxidation process of CNTs (o-CNTs). Though it is efficient, the whole craft is complex and toxic. In this thesis, CA instead of thionyl chloride is used to modify o-CNTs to prepare CA-CNTs. It is found that CA has been associated with the surface of o-CNTs by esterification. Thus the oxygen groups, especially the carboxyls, on the surface of CNTs have been enriched and they are 7%(wt) of total mass. At the same time, due to the modification by CA, the intertwining of CNTs has been further eased, and their surface electronegativity also reduces, which is conducives to increasing their hydrophilic property. When the ratio of CA to o-CNTs is 7:1, Zeta potential of the CA-CNTs is minimal, about-42.6 mV. So after CA modification, the reactivity of o-CNTs has been enhanced, which means it is beneficial to following reactions.In addition, in this thesis, the CTS/CA-CNTs are prepared through covalent bond and crosslink function. The results show that CTS is associated with the surface of CA-CNTs through amide bonds. And the phase structure of CA-CNTs has changed. The carbon graphite peak becomes lower when the amount of CTS increases. As the ratio of CTS to CA-CNTs getting to 7:1, the carbon graphite peak mostly disappears and CTS has coated CA-CNTs to form membrane. The CTS is about 55%(wt) of the total mass. Meanwhile the CTS/CA-CNTs composites have good absorption ability of GOD, which means they have a potential application in the field of biosensor.Moreover, in this thesis, Fe2+-CTS/CA-CNTs composites are prepared by using CTS/CA-CNTs to absorb Fe2+ions. The results show that the CTS on the surface of CA-CNTs absorbs Fe2+by its-NH2 groups. The maximum content of Fe2+is 3.394%(wt). Fe2+-CTS/CA-CNTs composites are superparamagnetic, and their maximum Ms is 2.57 emu/g, much better than the magnetism of Gadonanotube, indicating that they have a potential application in the field of MRI.更多还原