【作者】 张学骜；

【导师】 吴文健；

【作者基本信息】 国防科学技术大学 ， 材料科学与工程， 2007， 博士

【摘要】 针对有序介孔二氧化硅薄膜在光致变色伪装与生化战剂检测领域的应用需求,以贝壳珍珠层生物矿化机理研究为基础,进行了有序介孔二氧化硅薄膜的仿生合成及有机功能化改性,继而开展了活性分子在介孔薄膜中的组装及其性能研究,并探讨了两个不同领域应用的技术方案和可行性。率先对鲍鱼贝壳珍珠层的微结构进行了基于贝龄的动态分析,发现了珍珠层中文石晶体择优取向的变化,对于加深生物矿化的认识与更好地指导材料仿生合成具有重要意义。在此基础上,系统研究了蒸发诱导自组装合成有序介孔二氧化硅薄膜介观结构与孔径的影响因素及其调控机制,解决了介孔薄膜结构规整性与孔径调控技术难题,特别是从仿生合成的动态调控角度深入研究了溶胶陈化的影响及其关键作用,并采用分形维数与表面活性剂有效堆积参数对合成过程中出现的结构和参数变化进行了分析与解释。在纯硅介孔薄膜结构与孔径调控的基础上,引入3—氨丙基三乙氧基硅烷,通过直接共溶胶方式,仿生合成出不同介观结构和孔径的高氨基含量的介孔二氧化硅薄膜,成功实现了介孔表面的有机功能化改性。制备的薄膜样品具有较高的热稳定性,孔壁的氨基分布最高达到3.4个氨基/nm~2,为无机阴离子和生物分子的组装奠定了基础。随后,成功地将磷钼酸与细胞色素c分子组装在有序介孔中。组装后的介孔薄膜仍保持着高度的结构有序性,固定后的活性分子依然保持其分子构型和活性。这些特点主要归功于介孔薄膜稳定的无机骨架、适宜的孔径调控及功能化改性。将有序介孔二氧化硅薄膜应用于光致变色伪装及生化战剂检测是本文的一大创新。在前述合成、改性及组装研究工作的基础上,验证了单色变化的可行性,提出了光致变色复合体系新的机理,并解决了多色变化与图形构建的设计难题;通过对介孔薄膜修饰电极及其内容活性物质的电化学行为及其传感特性研究,成功构建了检测有机磷毒剂的生物传感装置,并提出检测多种生化战剂的新方法。更多还原

【Abstract】 To satisfy the application demands of photochromism camouflage and detection of biologic and chemical threat agents, ordered mesoporous silica thin films were prepared by a biomimetic synthesis method and modified with organsilane based on the biomineralization mechanism of nacre in shell. The assemblies and properties of active molecules in mesoporous silica thin films were studied, and the technical projects and feasibilities of the both applications were discussed.The dynamic analysis of microstructure of the nacre from the abalone with different shell ages has been investigated systematically for the first time. It is observed that some changes happen to the preferential orientation of aragonite crystals in the nacre, which is very important for further understanding the biomineralization process and instructing the biomimetic synthesis of materials. As a result, ordered mesoporous silica thin films were synthesized by evaporation-induced self-assembly process. The influencing factors and controlling mechanism of mesoporous structures and pore sizes were studied detailedly, and the technical problems of ordered degree and pore sizes adjusting of mesoporous films were solved. In particular, the effect of sol aging and its crucial action were investigated under the direction of the dynamic controlling view of biomimetic synthesis, and the theories of apparent mass fractal dimension and surfactant packing parameters were introduced to explain the changes of structure parameters in the synthetic process.According to the controlling mechanism of mesoporous structures and pore sizes of pure silica thin films, mesoporous silica thin films with high amino-groups content have been directly synthesized by co-condensation of 3-aminopropyltriethoxysilane and tetraethoxysilane, and the mesoporous surface was modified successfully with organosilane. The resultant thin films have preferable thermal stability, and the inner surface coverage of amino-groups is up to 3.4 amino-groups per nm~2, which is very useful and promising for incorporating inorganic anions and biomolecules into the mesoporous silica thin films.Subsequently, molybdenum polyoxometalate and cytochrome c were assembled into the amino-functionalized mesoporous silica thin films. After immobilization of active molecules, the ordered structures of mesoporous films and the molecular structures and activities of active molecules are still retained, which are attributed to the stable inorganic-framework, appropriate pore sizes and functional modification of mesoporous films.It is a very important innovation that the ordered mesoporous silica thin films are applied to the regions of photochromism camouflage and detection of biologic and chemical threat agents in this paper. Based on the forementioned researches including synthesis, modification and assembly, the feasibility of monochromatic change was testified, and the new photochromic mechanism of composite system was proposed, and the problems for designing multicolor and patterns were solved. Through the investigations of electrochemistry behavior and sensing performance of active molecules on mesoporous films-modified electrodes, the biosensor for detection of organophosphorus pesticides was developed successfully, and the new pathway for detection of multi biologic and chemical threat agents has been suggested.更多还原