利用铜基纳米材料制备金属有机框架物及其生长机理研究

发布时间：2018-04-01 05:38

本文选题：金属有机框架物　切入点：膜　出处：《浙江大学》2015年硕士论文

【摘要】：金属有机框架物(Metal-organic frameworks, MOFs)作为一种新型的多孔材料,具有极大的比表面积、可调控的孔洞尺寸和形状、骨架易被化学修饰,结构丰富等优点,在气体存储、气体吸附分离、传感、催化、药物释放等领域都有广阔的应用前景。将MOFs以膜的形式制备在硅片、多孔氧化铝、高分子膜等基底上,不仅高效经济适应未来的工业化生产,更能拓展其应用。但目前MOF膜的研究还出于发展期,连续致密的MOF膜的制备仍存在挑战,如致密性不好、反应能耗高、时间长,有机溶剂毒性大等,制约了性能的提高和生产的大规模化。同时,大多数MOFs都是在溶液中合成并形核长大,形核过程的对晶体形貌、尺寸以及薄膜质量等都有着重要影响,但鲜有针对此过程的研究。关于MOFs晶体和薄膜制备过程中添加剂对最终晶体形貌和性能影响的研究还处于初级阶段,尚没有明确的机理解释。针对以上问题,本文开展了利用表面带正电、活性高的铜基纳米材料制备金属有机框架物的研究。取得的主要创新性成果如下：1.采用氢氧化铜纳米线作为铜源,通过“水浴加热反应-冷却结晶”的方法制备出特殊的MOP-18管状晶体。通过控制冷却速率调节了晶体尺寸大小和形貌。研究了氨水作为添加剂在反应体系中的作用：对含羧酸的有机配体去质子化,促进氢氧化铜纳米线和有机配体配位形成MOP-18；在冷却结晶过程中,促成“扩散驱动不稳定”,使最终形成了管状晶体。2.利用氢氧化铜纳米线膜,通过室温溶液反应法,在氨和有机配体5-十二烷氧基间苯二甲酸摩尔比1：2,5-十二烷氧基间苯二甲酸浓度22 mmol/L左右的条件下,首次制备出连续的MOP-18膜。3.采用氧化铜纳米片作为铜源,以室温搅拌反应的方法在均苯三甲酸的乙醇／水溶液(vol乙醇：水=1：1)中快速制备出HKUST-1粉末。4.将氧化铜纳米片制备成膜,室温静置于添加了甲酸钠的、均苯三甲酸的水和乙醇溶液中,得到了连续致密的HKUST-1膜。采用不同溶剂进行反应发现,DMF和水均不适合,水和乙醇混合溶剂最优。同时,研究了甲酸钠作为添加剂对成膜的影响：由于对晶体表面有机配体有去质子化作用,提高反应程度,促使完全反应形成纯HKUST-1膜；提高晶体之间的互生,使膜更加致密；甲酸钠添加量的增加会显著提高反应速率。溶液中均苯三甲酸的最优浓度为5-10 mmol/L。在优化条件下得到的HKUST-1膜的理想分离因子分别是H2/CH4=2.90, H2/N2=3.61, H2/CO2=4.24,表现为基于努森扩散的气体选择性分离。
[Abstract]:Metal organic frameworks (Metal-organic, frameworks, MOFs) as a new type of porous material has great specific surface area, adjustable pore size and shape, the skeleton is easily modified, the structure of the advantages of rich in gas storage, gas adsorption and separation, sensing, catalysis, drug release and other fields have used broad prospects. The MOFs in the form of a film prepared on the silicon wafer, porous alumina, polymer film on substrate, not only efficient economy to adapt to industrial production in the future, it can expand its application. But at present the research of MOF film is in the period of development, continuous and compact MOF film preparation is still a challenge, such as dense bad reaction, high energy consumption, long time, organic solvent toxicity, which improve the large-scale production and performance. At the same time, because most of the MOFs in the solution synthesis and nucleation, nucleation process on crystal morphology, size And the film quality have a significant impact, but few studies in this process. The research on MOFs crystal and film preparation process, effects of additives on crystal morphology and properties of the final is still at the primary stage, there is no clear explanation of the mechanism. To solve the above problems, this paper carried out the research by the positively charged surface, copper base the preparation of nano materials of metal organic framework with high activity. The main contributions of this dissertation are as follows: 1. using copper hydroxide nanowires as copper source, preparation method by water bath heating and cooling crystallization reaction "to prepare MOP-18 tubular crystal special. By controlling the cooling rate of adjusting the size and morphology of crystal size was studied. Ammonia as additives in the reaction system in the role of organic ligands containing carboxylic acid deprotonation, promote copper hydroxide nanowires and organic ligands to form MOP-18; in the cold But in the process of crystallization, to promote the "diffusion driven instability", which eventually formed tubular crystals using.2. hydroxide nanowires film by reaction method at room temperature conditions in solution, ammonia and organic ligands 5- twelve alkoxy benzene two formic acid twelve mol ratio 1:2,5- alkoxy benzene two formic acid concentration of about 22 mmol/L under for the first time, the preparation of MOP-18 film by.3. continuous copper oxide nano sheets as copper source, ethanol / water solution with stirring at room temperature in all three formic acid (Vol ethanol: water =1:1) fast preparation of HKUST-1 powder.4. copper oxide nanosheets were prepared by the film, at room temperature in addition the sodium formate, all three formic acid water and ethanol solution, the continuous and compact HKUST-1 film. With different solvent reaction, and DMF are not suitable for water, water and ethanol mixed solvent. The optimal at the same time, the study of sodium formate as Tim Effect of additive on film: due to the deprotonation of the organic ligand crystal surface, improve the reaction degree, to completely formed by reaction of pure HKUST-1 film; improve the crystal between alternate, makes the film more compact; sodium formate additions will significantly improve the reaction rate. The optimal solution of ideal separation factor is the concentration of benzene three formic acid HKUST-1 film with 5-10 mmol/L. obtained at optimized conditions were H2/CH4=2.90, H2/N2=3.61, H2/CO2=4.24, is based on the selectivity of Knudsen diffusion separation.

【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.4

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