【作者】 李莉莉；

【导师】 冯嵬；

【作者基本信息】 北京化工大学 ， 化学工程与技术， 2012， 博士

【摘要】 碳纳米管(CNTs)是现代纳米材料中性能独特、优越且应用前景广泛的新型材料。它是由卷成筒状的石墨层组成，长度一般为微米级，直径可达到100nm。它有着非凡的机械、电子、热力学性能以及生物相容性，使它在生物医药及催化载体应用方面存在巨大的潜力。但是由于碳纳米管之间具有极强的疏水作用，在溶剂中碳纳米管易团聚，很难分散，从而限制了其应用。因此研究碳纳米管功能化，使其在溶液中分散性好且溶解度高，并实现功能化纳米管在蛋白吸附方面应用，是目前碳纳米管表面化学研究的一个热点。本论文研究制备一种水溶性高，分散稳定的功能化纳米管，通过红外、紫外、圆二、拉曼、XRD、XPS、热重、核磁，对功能化碳纳米管进行了表征；对功能化碳纳米管吸附蛋白后的复合体及对功能化碳纳米管与蛋白之间的相互作用进行了深入分析；对其固定化酶后的应用进行了讨论；对其在十六烷基双亲分子辅助下实现水相和有机相双相高浓度溶解及两相转移进行了细致研究，并将制备的功能化碳纳米管复合物进行酶固定化应用。具体工作总结如下：首先定位改性-环糊精合成氨基环糊精衍生物，然后与纳米管上活化的羧基进行酰胺键共价合成，制备高水溶性，高分散稳定性的新型氨基环糊精功能化纳米管。然后利用新的功能化纳米管对牛血清蛋白进行吸附，测得最大的吸附量。通过相互作用的紫外吸收光谱计算、圆二色性谱和红外光谱的定性定量分析，来推测载体与蛋白之间的相互作用机理以及分析在作用过程中对蛋白二级结构的影响。建立一种两相萃取体系，并选择在糖基双亲分子——十六烷基胺麦芽糖的辅助下，制备可以在水相和有机相均可以高浓度，均一分散的新型功能化纳米管复合物。对萃取体系中，有机相中醇的比例与作用、两相萃取时双亲分子与纳米管之间的最适萃取比例、两相溶剂的最佳比例及反萃取条件都进行优化和选择。在已建立的萃取体系中实现功能化纳米管复合物的制备及性能表征，并吸附酶实现在有机催化中的应用。还将萃取体系扩展到氧化纳米管，通过不同氧化程度纳米管的萃取分析及利用FTIR和XRD对萃取模型进行机理性推理，考察氧化纳米管复合物的特性及温度对于复合物之间氢键的影响。利用自己制备的新型功能化纳米管对生物大分子有着较高的吸附量，且很好地保持生物分子活性的优势，将这种纳米管载体应用于酶固定化。考察固定化酶的最大固定量及酶的活性保持情况，并比较酶固定化前后的催化能力。选用离子液体和有机溶剂的混合溶剂作为反应溶剂，利用脂肪酶的界面效应，提高反应速度和对映体选择性并在两相中实现固定化酶的方便有效分离，实现工业应用中的连续反应。同时对于两相体系中的界面效应进行机理性研究。此外，将功能化纳米管萃取复合物作为载体用于固定化酶，实现了固定化酶的双相溶解并应用于有机相酶催化。更多还原

【Abstract】 A novel amino-cyclodextrin was synthesized, and it was covalentlyattached to multiwalled carbon nanotubes (MWNTs). The functionalizedMWNTs (f-MWNTs) have very good aqueous dispersibility. Bovine serumalbumin (BSA) was adsorbed onto f-MWNTs through noncovalent interactions,including the hydrophobic interaction of the residues of BSA with the wall ofMWNT and the guest-host interaction of the residues with the cyclodextrin (CD)moieties of f-MWNTs. The Ultraviolet–visible (UV-vis) absorption of thef-MWNT-BSA hybrid was measured with UV-vis spectrometer; the absorbancecan be described well with the Beer Lambert law. The X-ray diffraction patternshave indicated that the crystalline form of BSA has been changed after theadsorption of BSA on f-MWNTs. The circular dichroism spectra have shownthat a high percentage of-helical content can be retained for BSA adsorbed on f-MWNTs. The results also indicate that the change of secondary structure ofBSA is mainly due to the hydrophobic interaction of the residues of BSA withthe wall of f-MWNT, while the secondary structure is much less affected by theinteraction of the CD moieties with BSA.Phase transfer of multi-walled carbon nanotubes (MWNTs) from anaqueous phase into an organic phase is achieved. The transfer utilizes thehydrogen-bonding interactions between the disaccharide group of a sugar-basedamphiphile and oxygenated functional groups on the surface of MWNTs. Thedispersion of carbon nanotubes in a wide range of organic solvents is enabled,which represents the first example of solubilization of carbon nanotubes inorganic solvents via hydrogen bonding interactions.The immobilized lipase was utilized for the resolution of the modelcompound (R, S)-1-Phenyl ethanol in heptane, the ionic liquid [Bmim]PF6aswell as the heptane/[Bmim]PF6mixture. In the reaction media, the enzymaticactivity by the immobilized lipase is much higher than that by the free lipase. Incomparison to the catalysis in the ionic liquid and heptane, when using themixture of heptane/[Bmim]PF6as the reaction medium, the catalysis by theimmobilized lipase at the heptane-ionic liquid interface exhibited a highercatalysis activity. This is due to two aspects: the continuous diffusion ofsubstrate from the heptane phase to the ionic liquid phase; the simultaneousextraction of product from the ionic liquid phase. In addition, the interfacial enzymatic catalysis facilitates the reuse of the immobilized lipase and the ionicliquid.更多还原