【作者】 张磊；

【导师】 阎子峰；

【作者基本信息】 中国石油大学 ， 化学工程与技术， 2008， 博士

【摘要】 本论文围绕介观限制空间与客体分子空间结构的相互匹配性展开,合成出了一系列具有不同介观结构、形貌以及各种功能化基团的多孔材料和核壳材料。新材料的合成,除了研究其内在的反应机制外,更为重要的是开发其全新的功能,结构与功能的结合永远是科学家们关注的重点。在论文中,我们设计合成了具有不同介观限制空间的材料,并将纳米复合阵列的空间结构与客体分子三维空间结构的相互匹配性关联,结合具有不同空间结构的纳米材料特点,将其应用于选择性生物磁分离、可控药物靶向传输以及生物传感器等领域。第2章中,以无毒、廉价的硬脂酸铁为有机铁源,在高压反应釜中低温(250℃)制备出了超顺磁单分散纳米磁性晶体。然后,我们将所制备的超顺磁单分散纳米磁性晶体成功地包埋进入介孔氧化硅微球中。所制备超顺磁磁性微球的三维空间结构可调变,高比表面,孔径极为均一、可调,维度有序、具有强超顺磁性。更重要的是,我们以具有不同三维空间尺寸和分子量的细胞色素(Cyt c)和牛血清蛋白(BSA)为模型生物蛋白分子,将制备的磁性介孔氧化硅微球应用于基于生物分子空间结构的磁性分离。结果表明,依据生物分子空间结构的匹配性能,所制备的超顺磁磁性微球能够将不同尺寸生物蛋白有效的进行分离。第3章中,以非手性的表面活性剂作为结构导向剂,通过含有疏水性有机功能基团的硅源与正硅酸乙酯进行共聚,一步合成了具有同时控制功能化以及手性孔道的MCM-41型螺旋介孔材料。通过仔细的表征,我们成功地合成出了一批具有不同尺寸和螺旋程度的螺旋介孔材料。更重要的是,我们通过实验结果提出了一种由短胶束向一束二维六方直胶束转变,以及一束二维六方直胶束向一束二维六方螺旋胶束的转变自发驱动螺旋产生的机理。此外,我们考察了手性螺旋功能化介孔材料作为药物传输载体对阿司匹林的药物传输能力。结果表明,在药物传输过程中,药物释放的速度可以通过手性螺旋功能化介孔材料的形貌以及螺旋结构进行控制。第4章中,通过非手性表面活性剂、磁性纳米晶和无机硅物种的自装制备出了以磁性纳米晶为核,以手性螺旋介孔材料为壳层的磁性核壳材料。此外,考察了手性螺旋磁性核壳材料作为药物传输载体对阿司匹林的药物传输能力。结果表明,在药物传输过程中,药物释放的速度可以通过手性螺旋磁性核壳材料的形貌以及螺旋结构进行控制,具有手性螺旋介孔结构的磁性核壳材料有望应用于磁靶向药物的可控传输。第5章中,构造了一种基于固定二甲基亚砜还原酶的碳纳米管生物传感器。将二甲基亚砜还原酶(DMSOR)固定于碳纳米管制成工作电极作为生物传感器。研究表明碳纳米管促进了酶与电极表面之间的电子转移。该电极有望在DMSO生物传感器方面得到应用。第6章中,以碳纳米管与水溶液界面的阳离子表面活性剂十八烷基三甲基溴化铵(ODTMA)超分子自组装结构为模板,在水溶液体系成功地合成了以碳纳米管为核,以高度有序介孔硅基材料为壳的碳纳米管/有序介孔氧化硅核壳纳米线。此外,将二甲基亚砜还原酶固定于核壳纳米线制成工作电极作为生物传感器。介孔硅较大的比表面积,从而可以提高其吸附酶的能力,并且由于其具有亲水性而使其容易在水中分散。研究发现核壳纳米线结构对酶与电极表面的电子传输有促进作用。该电极有望在DMSO生物传感器方面得到应用。更多还原

【Abstract】 This thesis is concerned with the fabrication of several mesoporous silica materials that are especially tailored to accommodate guest molecule encapsulation-transportation process. In this project I have studied the formation mechanism and surface modification on designing the mesoporous silica with different morphologies (e.g. spherical, helix), mesopore structures in order to meet the requirement as host material of several kind biomolecules/drug molecules. Furthermore, I have done the observation on this novel material for several potential applications like: size-selectivity bioseparation, targeted drug-delivery, and biosensor according to their different pore structure. More detailed work for each chapter in this thesis is discussed as follow:In chapter 2, we report a novel synthesis and selective bio-separation of the composite of Fe3O4 magnetic nanocrystals and highly ordered MCM-41 type periodic mesoporous silica nanospheres. Monodisperse superparamagnetic Fe3O4 nanocrystals were synthesized by thermal decomposition of iron stearate in diol in autoclave at low temperature. The synthesized nanocrystals were encapsulated in mesoporous silica nanospheres through the packing and self-assembly of composite nanocrystal-surfactant micelles and surfactant-silica complex. Different from previous studies, the produced magnetic silica nanospheres (MSNs) possess not only uniform nanosize (90~140 nm) but also a highly ordered mesostructure. Binary adsorption and desorption of proteins cytochrome c (cyt c) and bovine serum albumin (BSA) demonstrate that MSNs are an effective and highly selective adsorbent for proteins with different molecular sizes.In chapter 3, we report a novel one-step synthetic pathway that controls both functionalities and morphology of functionalized periodic helical mesostructured silicas by the co-condensation of tetraethoxysilane (TEOS) and hydrophobic organoalkoxysilane using achiral surfactants as templates. Different from previous methods, the hydrophobic interaction between hydrophobic functional groups and the surfactant as well as the intercalation of hydrophobic groups into the micelles are proposed to lead to the formation of helical mesostructures. Our study demonstrates that these hydrophobic interaction and intercalation can promote the production of long cylindrical micelles, and that the formation of helical rod-like morphology is attributed to the spiral transformation from bundles of hexagonally-arrayed and straight rod-like composite micelles due to the reduction in surface free energy. Furthermore, the helical mesostructured silicas were employed as drug carriers for the release study of model drug, aspirin, and our results show that the drug release rate can be controlled by the morphology and helicity of the materials.In chapter 4, we report a one step synthesis of magnetic helical mesostructured silica (MHMS) rod by self-assembly of an achiral surfactant, magnetic nanocrystals with stearic acid ligands and silicate. This core-shell structured material consists of a Fe3O4 superparamagnetic nanocrystal core and a highly ordered periodic helical mesoporous silica shell. Furthermore, the drug release process is demonstrated using aspirin as a drug model and MHMS as a drug carrier in a sodium phosphate buffer solution.In chapter 5, Dimethyl sulfoxide reductase (DMSOR) was immobilized into carbon nanotubes, which was cast onto the surface of GC electrode, and used as the working electrode (DMSOR-CNT/GC electrode). The results indicated that the electron transfer between DMSOR and GC electrode promoted by carbon nanotubes can be easily performed through their surface-controlled process; they have potential application as DMSO biosensor.In chapter 6, we reported a synthesis of carbon nanotubes (CNTs)/mesostructured silica core-shell nanowires with a carbon nanotube core and controllable highly ordered periodic mesoporous silica shell via the interfacial surfactant template. The results indicate that the core-shell nanowires have highly ordered periodic mesoporous silica shell (space group p6mm), high BET surface area and narrow pore size distribution. The core-shell nanowires have promising applications in biosensors, nanoprobes, and energy storage due to their high surface area, high loading amount of enzyme and good disperse ability in polar solvents. When the core-shell nanowires immobilized with DMSOR was cast onto the surface of electrode, this can be functioned as the working electrode. The results indicated that the electron transfer between DMSOR and GC electrode promoted by core-shell nanowires and the electrode have potential application as DMSO biosensor.更多还原