【作者】 朱微末；

【导师】 王艳芹；

【作者基本信息】 华东理工大学 ， 工业催化， 2011， 硕士

【摘要】 本论文针对介孔金属复合物纳米结构和磁性核/壳纳米结构材料的合成与应用开展了基础研究。介孔材料由于具有高的比表面积、可调控的孔径大小、孔道的长程有序排列而被广泛地研究。而多功能的磁性核/壳纳米结构材料由于其独特的性能在生物医学临床诊断和综合治疗方面具有潜在的应用前景。在论文第一部分(第三章),我们采用纳米硬模板技术,以大孔径的3D-KIT-6 (Iα3d)为模板,水为溶剂合成了介孔3D-NiFe2O4 Iα3d)铁氧体材料。模板的介孔孔道起了纳米反应器的作用,水作为单一溶剂更绿色环保。合成材料比表面积达到121m2/g,平均孔径大小为3nm,平均孔壁厚度为7nm,在磁学性质上表现为和纳米磁体一致的超顺磁性。将介孔3D-NiFe2O4 (Iα3d)铁氧体材料作为先进的微波吸收材料,发现当其匹配厚度为3mm时,在高频X波段(8.5～12.5GHz)范围有较强的吸收,在12GHz吸收强度达到-22.5dB。因此其可以作为先进的微波吸收材料应用在电子、军事隐身等各个高科技领域。在论文第二部分(第四章),我们采用介孔Co3O4(Ia3d)为前驱体,利用连续原位生成的金属Co0纳米颗粒为催化剂,通过Boudouard歧化反应,合成了石墨包覆金属钴核/壳结构纳米胶囊材料。和已报道的研究结果不同的是,在合成中并没有发现有副产物碳纳米管和碳纳米纤维的存在。高度结晶的金属钴主要是以六方晶相存在,平均粒径大小为25nm,被8～9nm的石墨壳层所包覆,磁饱和量达到85emu/g。原位生成的石墨壳层不仅保护金属钴核使其免受外界化学环境的进攻,而且提高了其生物兼容性和官能化程度。将拟平面分子二甲酚橙(XO)作为模型分子,研究证实XO可以与石墨壳层发生π-π堆叠耦合作用。通过模型分子实验说明该材料可以应用在生物医学的药物靶向治疗方面。同时,我们也用相同的方法合成了石墨包覆合金(Fe2Co、Fe0.64Ni0.36)的核壳纳米结构材料。更多还原

【Abstract】 Multi-functional nanostructured materials including mesoporous metal oxides and core/shell hybrid materials were deeply investigated here. As well known, mesoporous materials have high surface area, tunable pore size and periodic pore arrangement and have been widely studied. On the other hand, multi-functional core/shell magnetic particles have their own advantages because they can provide many exciting opportunities in biomedical studies for integrated diagnosis and therapeutic applications.In chapter three, ordered mesoporous nickel iron spinel has been synthesized by using KIT-6 as template through nanocasting technique. The nanospace in the template material plays as a nano-reactor, water is the only solvent used in this method, which is environmentally friendly. The characteristic results from X-ray diffraction (XRD) analysis, energy-dispersive X-ray spectrometry (XPS), transmission electron microscopy (TEM), high resolution scanning electron microscopy (HR-SEM), nitrogen sorption analysis and magnetization measurements demonstrated the successful synthesis of ordered mesoporous nickel iron spinel with large surface area (121 m2g-1) and superparamagnetism. Using it as a microwave absorption material, the maximum reflection loss was -22.5dB that was obtained at 12GHz with the matching thickness of 3.5mm.In chapter four, hermetically-sealed graphite-encapsulated cobalt core/shell nanostructures have been prepared by the CO Boudouard reaction using in situ generated cobalt as the catalyst. Only core/shell nanostructures were obtained, rather than a mixture of cobalt nanoparticles with carbon nanotubes or nanofibers. The magnetic cobalt nanoparticles are highly crystallized with a hexagonal-close packed crystal phase (average diameter of ca.25nm) and coated with an 8～9nm thick graphitic shell. The nanostructures have a high saturation magnetization of 85emu/g and can be easily separated by an external magnet. The creation of the hermetically-sealed graphitic shell not only keeps the magnetic cobalt nanoparticles from reacting with strong mineral acids, but also has biocompatibility and makes further functionization easy. A pseudo-planar aromatic molecule, xylenol orange, was used as the model molecule because it can be absorbed on the graphitic shell mainly byπ-πstacking interaction. This was confirmed by Raman and ultraviolet-visible spectroscopy. Graphite encapsulated Fe2Co and Fe0.64Ni0.36 alloy core/shell nanostructures were also fabricated by this method.更多还原