【作者】 鲍春晓；

【导师】 杨柏；

【作者基本信息】 吉林大学 ， 高分子化学与物理， 2009， 硕士

【摘要】 随着纳米科学技术的不断发展以及对物质世界探索的不断进步,近年来,通过对各种尺度的纳米材料的精确合成、复合和组装,人们期待强化材料的光、电、磁、催化等各类物化性能,以期突破当今微电子工业发展的瓶颈,并在化工、医药、环境等传统和新兴工业中开拓出新的领域。本文正是基于这一思路,在水溶液中制备传统的稀土铕配合物基础上,使其在阳离子表面活性剂十六烷基三甲基溴化铵(CTAB)的诱导下自组装成纳米线,此过程中,其良好的发光性质得到保持。此后我们通过改变的实验条件,得到了形貌可控的铕配合物的纳米球、纳米环、纳米方块、微米片层结构、囊泡结构等,并通过实验总结分析了影响形貌的主要因素,此外,还将此种自组装方法应用到其它的稀土元素及铁元素,以期得到更多更好的具有应用前景的材料。更多还原

【Abstract】 Rare earth complexes have potential applications in the fields of optical display, laser materials, optoelectronic conversion because of their excellent properties such as high fluorescence efficiencies, wide spectral region, excellent fluorescence monochromaticity and large Stokes shift. Along with the widely application of functional materials in modern society, the development of rare earth complexes will face great chances and challenges. The composition of rare earth complexes and other functional materials are expected, because such materials will possess the advantages of each component, moreover the optical, electrical and magnetic properties of each component will also be improved. At the same time, continuous development of nanotechniques bring infinite vital force to the scientific researches on rare earth complexes. The band structures and fluorescent properties of nano-scaled rare earth complexes are new completely new fields waiting for researchers to explore. Furthermore, fluorescent rare earth complex nanomaterials will no doubt play important roles in the fields of optoelectronic devices and fluorescent labeling, etc. How to combine the properties of rare earth complexes with other functional materials and how to prepare and assemble of rare earth complex nanomaterials are the most important two subjects in recent years.In chapter 2, we prepared two kinds of rare earth complex nanowires using cationic surfactants as the soft template. We measured the composition and shape of the prepared nanowires. The nanowires are composed of Eu(DBM)4CTAB (Eu-CTAB) and Eu(DBM)4CPB (Eu-CPB) respectively. By using two different surfactants, we have prepared two different shapes of nanowires. Using CTAB we got straight line shaped nanowires, while we got curve-like nanowires in case of CPB. The lengths of the nanowires are above 20μm and 50μm respectively. A cross-section of rectangular shape was found for both of the two nanowires, with a width and thickness of 200 nm and 80 nm for Eu-CTAB and 250 nm and 60 nm for Eu-CPB respectively. We characterized the photoluminescence of the nanowires, and found that the surfactants can not only act as the soft template but also improve the luminescent intensity. Surfactants in aqueous solution form micelles spontaneously, and growth of the rare earth complexes are restricted by the micelles. Quenching of water molecules is reduced by the formation of nanowires because of the surfactants, thus improved the luminescent intensity of the rare earth complexes. We are working on the formation mechanism of the nanowires and trying to find new applications of the rare earth complex nanowires.In chapter 3,on the basis of chapter 2 which conduct a self-assembly method of preparing rare earth complex nanowires induced by surfactants, we changes the experimental conditions, then obtained different structures such as nanospheres, nanosquares, microsheet, nanorings. We analyzed the influencing factors which play important roles on the morphologies of rare earth complex, and then we found that the following four factors determine the behavior of Surfactant micelles, also the formations of various morphologies of rare earth complex.First, different concentrations of surfactant make the formation of different morphologies. At low surfactant concentration the normal micelle is spherical, as the concentration of surfactant increases,spherical micelle gradually become flexible rod-like micelles,correspondingly, the morphology of europium complex also changes from the initial nanospheres into nanowires.Second, different morphologies appear in the presence of different surfactants even under the same experimental conditions. In this thesis, The most commonly used surfactants are the single-chained, cationic Surfactants, based on the preparation of Eu-CTAB nanowires, we introduce three types of surfactants as follows: CPB was introduced with a different hydrophilic group, dodecyltrimethylammonium bromide (DTAB)with different length of hydrophobic chain, cetyltrimethylammonium chloride ( CTAC ) with different counterions, then we found that Eu-CPB nanostructures are more flexible , Eu-DTAB nanostructures are with small aspect ratio, Eu-CTAC nanostructures are very similar to Eu-CTAB nanostructures.Third, volume ratio of ethanol and water also has a certain impact on the morphology. Because the addition of ethanol greatly affects the CMC value of surfactant, therefore, rod-like micelles change into lamellar micelles, morphology of europium complex changes into microsheetFourth, the addition of organic solvents(DMF)leads the formation of europium complex structures of the vesicles. However, due to rapid evaporation of the DMF, so the structure is not stable.Finally, in accordance with controllable preparation process of europium complex nano/microstructures, we have also studied the preparation of iron complex nano/microstructures. We have successfully prepared iron complex nanowires and nano-helix structures. However, the assembly process is instable, which remains to be further studied, in order to get a variety of iron complex nano/microstructures with good performance.更多还原