【作者】 王瑜；

【导师】 黄进；

【作者基本信息】 武汉理工大学 ， 药学， 2010， 硕士

【摘要】 纳米材料由于其优异的性能,在生物医学材料、催化材料、太阳能电池、传感器等领域具有广泛的应用前景。具有特殊形貌和尺寸的纳米材料可控制备以及其相应的性质是现代材料科学的一个研究热点。本文的主要工作是以液相化学合成法为基础,探索纳米材料的可控制备新途径。这些纳米材料分别是：MnO／NiO纳米颗粒、MnS纳米棒、CdSe量子点。通过调控体系中的关键性实验参数,成功实现这些材料的形貌和尺寸的可控制备,对所制备的材料进行结构表征和性质研究,并对其形成机理进行了探索性研究。(1)选用Mn(CH3COO)2·4H2O为前体,以油酸和油胺为表面活性剂,在十八烯溶剂中用“一锅法”制得类四角星形状的MnO纳米晶,讨论了表面活性剂浓度及反应时间对MnO形貌和粒径的影响。并且在实验中发现,体系中少量水的存在,对得到该特殊形貌的锰氧化物纳米粒子有重要影响。研究了具有特殊形貌的纳米晶经氧化后的形貌、物相以及对亚甲基蓝染料分子的吸附性能。基于对锰氧化物纳米粒子制备的研究基础,选用纳米镍氧化物作为延伸,将锰氧化物的制备方法应用于镍氧化物的制备,制备得到形貌、对制得的纳米NiO进行磁性能测试,该样品在常温下呈现软铁磁性。(2)以液相合成法为基础,选用Mn(CH3COO)2·4H2O和硫粉为原料,首次通过多次注入前驱体的方法,成功制备得到了硫化锰纳米棒,研究了不同的制备条件如注入前驱体的量及时间对MnS纳米棒形状及分布的影响。根据实验结果,对其生长机理进行了初步的探讨。(3)利用非金属有机前驱体法,制备了粒径均匀,分散性良好的CdSe纳米晶,通过紫外-可见吸收光谱、荧光发射光谱、透射电镜等表征手段研究了制备条件对量子点光学性质的影响,结果表明所合成的CdSe量子点的吸收峰范围在526～580nm,采用较大的初始Cd／Se比值有利于得到发光性质更好的CdSe纳米晶。实验中发现经油酸稳定的CdSe纳米晶较经硬脂酸稳定的CdSe纳米晶具有更好的光稳定性,对其可能的原因进行了分析。最后,初步尝试利用“绿色”合成法制备得到了长径比约为3：1的CdSe纳米棒。本文通过对纳米材料的形貌控制合成研究,探索可控合成晶粒尺寸均匀,分散良好的纳米材料的方法,探讨不同纳米材料的晶粒生长行为,进而揭示其形成机理,并研究其微结构与性能之间的关系,其结论将对类似纳米材料的制备提供实验依据和理论支持。更多还原

【Abstract】 Nanomaterials have shown a large number of potential commercial applications in the fields of biomedical materials, catalytic material, solar cells and sensors et al. The controlled synthesis of nanomaterials with specific morphology and size besides of its properties study has been a research focus of materials science. The object of this dissertation is to explore new controllable synthetic methods to nanostrucured materials based on liquid-phase chemical synthesis method. Several nanostructured have been investigated including MnO/NiO nanocrystals, MnS nanorods and CdSe nanocrystals. Those materials with controllable morphology and size have been successfully synthesized by adjusting the crucial factors in the reaction system, and discuss the possible formation mechanism of these materials. The structures and properties of as-prepared materials have been characterized.1. Novel quadrangle MnO nanoparticles were one-pot synthesized by the thermal decomposition of Mn(CH3COO)2·4H2O as precursor in octadecene, using oleic acid and oleyl amine as surfactants. The influences of experimental parameters, including the concentration of the surfactants and the reaction time were investigated. The presence of small amounts water in the reaction system has been found get a major impact of the formation of the special morphology of the manganese oxide nanoparticals. The as-prepared MnO nanoparticles were further partially oxidized and the morphology, structure and the dye adsorption properties to methylene blue after oxidized were studied. Based on the work bases on manganese oxide, nickel oxide has been chose as the pattern system to be synthesized used the manganese oxide method. The magnetic properties of the as-prepared NiO nanoparticles were investigated. They showed soft ferromagnetism at room temperature.2. Based on liquid-phase chemical synthesis method, used Mn(CH3COO)2·4H2O and sulfur as precursors, we first successfully synthesized MnS nanorods by injected the precursors interval. The influences of experimental parameters, including the injection volume of the precursors and the injection interval on the shape and the distribution of the MnS nanorod were investigated. The primary formation mechanism has also been studied.3. Monodispersed CdSe nanocrystals were prepared through organometallic precursor method. Influences of preparation condition on the optical properties of the quantum dots were investigated by Uv-vis absorption spectroscopy, fluorescence spectroscopy and transmission electron microcopy (TEM) et al. The results show that the adsorption of as-prepared quantum dots was in 526～580 nm. A larger initial Cd: Se ratio of the precursors method represents a series of excellent emitters in term of their PL, QY, the fwhm of the emission. The photo- stability of the CdSe nanocrystals which used oleic acid as stabilizer was much better than those used stearic acid as stabilizer and the possible causes were analyzed. Finally, we made a primary study of prepared CdSe nanorods with 3:1 aspect ratio though greener approach.The aim of this thesis is based on the study of morphology controllable synthesis of nanomaterials, explore new chemical routes for the synthesis of Monodispersed nanocrystals, investigate the growth behavior of different nanomaterials and reveal their formation mechanisms. Finally, study their relationship between their microstructure and properties. The study results will provide experimental foundation and theoretical support to the preparation of nanomaterials with similar structure.更多还原