【作者】 贾向东；

【导师】 朱俊杰；

【作者基本信息】 南京大学 ， 分析化学， 2011， 博士

【摘要】 纳米氧化物及其复合材料在传统材料增强和功能化、药物缓释和靶向、分离和纯化、生物传感等领域有着重要的应用前景。纳米氧化物通过与其它功能材料的杂化或复合,既保持了原有材料的性能,又产生了新奇效应。许多材料的奇特性能,就是通过复合或杂化的方式而得到的。发展构建这些纳米结构单元材料的新方法；探究这些单元进行周期性有序组装以扩展尺度的原理,直至得到全新材料或器件；发展对于这些材料微相结构的控制手段,具有重要的理论价值和现实意义。在本论文工作中,我们对SiO2和ZnO及其复合材料的合成方法、介观结构、相应性质和传感应用进行了讨论。结合纳米材料的基本理论,以构效关系为主线,对于这些氧化物及其纳米复合物材料的结构和性能进行了研究。本论文研究工作主要包括以下几方面的内容：第二章,通过动态调节混合溶剂体系的组成,实现表面配体的交换和调制,以氧化硅水溶胶和聚二甲基硅氧烷(PDMS)在酸性条件下直接反应,形成杂化界面,制备了核壳结构的单分散氧化硅/PDMS纳米复合材料。对于其反应机理进行了讨论,开展了其作为增强材料在光固化涂层中的应用研究。结果表明,合成的单分散核壳材料易于分散于不同的有机体系,较小的添加量可以明显改善涂层的性能。第三章,在丙三醇体系,通过氢氧化钾和氯化锌反应,合成了两种花状氧化锌纳米晶。运用SEM、XRD、红外和紫外光谱等分析技术对其进行了表征。并对于其在电化学传感器中的应用进行了研究。结果表明,合成的氧化锌有较好的分散性,构建的电化学传感器对于过氧化氢有良好的响应。第四章,以单分散纳米氧化锌球为原料,运用原位模板,通过简单的超声辅助液相转化法选择性地合成了核壳结构ZnO球/CdS棒和ZnO球/CdS粒子的纳米复合材料。其形成机理与超声辐射密切相关。对合成的核壳结构纳米材料的光致发光和电致化学发光性质进行了研究。第五章,使用六次甲基四胺和柠檬酸三钠作为形貌控制剂,运用微波水热法,合成了有较好分散性的中空六角状圈形结构的Au/ZnO纳米复合物,该结构是由层状氧化锌和随机分散于表面的Au纳米粒子紧密组装而成的。通过XRD、SEM、TEM、紫外-可见、PL光谱等分析技术对该结构进行了表征,并对其光学性质进行了研究。更多还原

【Abstract】 Nanooxides and their composites are important materials showing promising potentials in reinforcement and functionalization of classic materials, drug targeted delivery, separation, purification, biosensors and so on. Oxide nanocomposites possess not only the combination of the functions inherited from its contents but also novel properties resulting from the synergism among them. Developing new methods for synthesizing different nanoparticles, controlling the assembly process for periodical regular structure searching for novel functionality and even designating functional device, studying the factors affecting their mesostructure and the relationship between property and structure should be beneficial for theoretical investigation as well as the application of the oxide nanomaterials and their composites.Following the methodology above, this dissertation presents a systematic research on the relationship among the synthesis, structure, property and application for several oxide nanoparticles and their composites. The main results were summarized as follows:Chapter 2:A core-shell hybrid nonocomposite composed of silica and polydimethylsilane (PDMS) was successful synthesized by a novel solvent adjustment strategy through the direct reaction between silica nanoparticles and PDMS by using cheap commercial aqueous silica sol. The nonocomposite was characterized and a possible mechanism was discussed. A preliminary application for the nanocomposites in coating material was carried out which revealed obvious improvement in the property of the coating film.Chapter 3:Two kinds of flower-like zinc oxide nanocrystals were synthesized by mixing KOH and ZnCl2 in glycerol solution. The experimental parameters affecting the formation of the nanocrystals were optimized, and possible mechanism was discussed. The obtained products were characterized with XRD, SEM techniques and UV-Vis spectroscopy. The results indicated that the flower-like nanocrystals were hexagonal wurtzite structure. In addition, hemoglobin (Hb) was immobilized on the ZnO nanocrystals. It was found that the flower-like ZnO could enhance the direct electron transfer of Hb. The results showed that the as-fabricated biosensor had a good linear amperometric response to H2O2 in the concentration range from 1×10-6 to 1.2×10-4 mol L-1.Chapter 4:The core-shell type ZnO nanosphere/CdS nanorod and ZnO nanosphere/CdS nanoparticle composites have been selectively prepared through a simple ultrasound-assisted solution phase conversion process。using monodispersed ZnO nanospheres as a starting reactant and in situ template. The formation mechanism of the products is closely connected with the ultrasonic effect. The photoluminescence and electrogenerated chemiluminescence properties of the as-prepared core-shell structures were investigated.Chapter 5:By using hexamethylenetetramine and sodium citrate as the reaction, morphology and assembly control agents, a well dispersed hollow hexagonal ring-shaped structure of ZnO/Au nanocomposite was successfully fabricated through microwave assistant hydrothermal method. The composite is composed of layered ZnO and randomly scattered Au nanoparticles on the surface. The composite was characterized by XRD, SEM, TEM. Its optical properties were investigated according to UV and PL spectra and a possible mechanism of the formation for the as prepared composite was proposed.更多还原