【作者】 王玮；

【导师】 裘灵光；

【作者基本信息】 安徽大学 ， 物理化学， 2010， 硕士

【摘要】 金属-有机骨架材料(MOFs)作为一种新型的具有多种功能的多孔材料,以其独特的拓扑结构以及在气体贮存、光学、催化、医学、选择性吸附和磁性材料等领域巨大的潜在应用前景而受到广泛关注。最近,另一研究热点是围绕合成由各种多功能有机配体和金属离子构筑的金属-有机骨架纳米晶而展开的,它是一种在分子水平上高度可剪裁的有机-无机-杂化纳米材料。合成纳米尺寸的金属-有机骨架材料,使它们具有更加广泛的用途,包括：生物传感、磁共振成像、异相催化、模板、自旋交叉、生物传感、生物医学成像和抗癌给药等领域,这为发展新一代功能纳米材料提供了一个令人振奋的应用前景。通常合成纳米金属-有机骨架的主要方法有溶剂-诱导沉淀法、微乳法、水热(溶剂热)法和超声合成法等。在本论文中,我们创新性的大胆引入表面活性剂和高分子作为模板,辅助合成具备不同形貌和尺寸的荧光纳米金属-有机骨架材料,同时进一步研究了此材料对于硝基化合物的敏感性。本论文的主要研究内容如下：1.在常温常压下,以Zn(Ⅱ)、Dy(Ⅲ)、Eu(Ⅲ)为金属中心,分别以对苯二甲酸和间苯二甲酸为配体,以表面活性剂(CTAB)为模板合成了具有二维结构的MOFs Zn(BDC)-xH2O (x=1-2) 1、[Dy2(BDC)3(H2O)4]n 2和[Eu2(BDC)3(H2O)2]n3纳米晶,并考察了反应时间与纳米晶形貌和尺寸之间的关系。用粉末X-衍射(PXRD)对在不同条件下获得的产物进行结构表征,结果证实获得的就是目标产物。此外,由扫描电镜(SEM)和透射电镜(TEM)照片显示,通过控制反应时间,能够有效的调控纳米晶尺寸和形貌。2.分别研究了上述三种金属-有机骨架纳米晶对硝基苯、邻硝基甲苯、对硝基甲苯、2,4-二硝基甲苯以及2,6-二硝基甲苯的荧光敏感性。性质研究表明,它们对硝基类化合物具有响应速度快、敏感性强的特点,有望开发出有重要意义的荧光传感器、荧光探针等,对于未来广泛应用于爆炸物的检测中具有潜在的价值。3.以高分子为软模板,采用水热法合成了以锌为金属中心,以异烟酸和顺丁烯二酸为双配体的具有不同尺寸和形貌金属-有机骨架纳米晶。并通过控制反应时间,可以定向合成具有确定形貌特征的MOFs纳米晶,如纳米片、纳米带、纳米棒等。性质研究显示,所得纳米晶在蓝光区域展示强烈的光致发光性质。在乙腈溶剂中,定量分析了纳米晶荧光光谱对硝基化合物的敏感。结果显示,纳米晶对硝基化合物分子具有高度的敏感,这对设计新颖的对有机客体分子敏感的荧光传感器,具有潜在的应用价值。更多还原

【Abstract】 As a new class of multifunctional porous materials, metal-organic frameworks (MOFs) have attracted considerable interest, owing to not only their intriguing structural motifs but also their potential applications in gas storage, photonics, catalysis, medicine, selective guest adsorption and magnetic materials. More recently, synthesis of nanoscale MOFs (NMOFs) built up by metal ions and various polyfunctional organic ligands components at the molecular level has recently afforded a new class of highly tailorable hybrid nanomaterials. Scaling down these materials to the nano-regime has enabled their use in a broad range of applications including biomedical imaging, MRI contrast agents and catalysis. These results underscore the exciting opportunities of developing next-generation functional nanomaterials based on molecular components.Some traditional techniques, such as formation and precipitation of particles triggered by the introduction of a solvent into a solution of ligands, microemulsion techniques and solvothermal synthesis, are applied to prepare MOFs and NMOFs. In this dessertation, we present a morphology-controlled synthesis of NMOFs by using a template-assisted method for potential fluorescent sensing of nitroaromatic explosives. Actually, surfactants and polymers have been widely utilized as surface stabilizers and templates in the synthesis of nanoparticles. The presence of surfactant molecules during the formation of particles can decrease the surface energy, control the growth and shape of the particles, which is due to their binding to the nanoparticle surface.The main contents of this dessertation are as follows:1. Nanocrystals of two-dimensional (2-D) MOFs, Zn(BDC)·xH2O (x= 1-2) 1, [Dy2(BDC)3(H2O)4]n 2 and [Eu2(BDC)3(H2O)2]n 3, were synthesized at an ambient temperature and atmospheric pressure under different conditions. The structures were confirmed by powder X-ray diffraction (XRD) patterns. In addition, scan electron microscopy (SEM) and transmission electron microscopy (TEM) images of 1-3 reveal that size and shape of nanocrystals can betuned by varying the reaction time. 2. Fluoresent sensing of nitrobenzene,2-nitrotoluene,4-nitrotoluene, 2,4-dinitrotoluene and 2,6-dinitrotoluene to nanocrystals have been studied respectively. The results indicate that nanocrystals of MOFs 1,2 and 3 are highly sensitive to nitroaromatic compounds. The results may be helpful for designing novel fluorescence sensor for the sensing of explosives.3. We also present a morphology-controlled synthesis of NMOFs by using a polymer-assisted method. The results indicated that size and shape of nanocrystals can be tuned by varying the reaction time in the presence of polymer. The samples in this work exhibited strong blue solid state photoluminescence properties. The sensing of nitroaromatic compounds in an acetonitrile solution was quantitatively analyzed by a fluorescence spectrometric titration experiment. The experimental data suggest that the nanocrystals are highly sensitive to nitroaromatic compounds. This may be helpful for designing novel fluorescence sensor for the sensing of organic guests.更多还原