类水滑石复合材料的合成及其在环境毒物方面的应用

发布时间：2018-08-04 21:24

【摘要】：类水滑石(Layered Double Hydroxides,LDHs),由于其特殊的层状结构,在催化,光催化,吸附,电化学,生物技术等方面引起研究者们极大的兴趣。作为一种无机层状材料,LDHs是由层间阴离子及带正电荷层板堆积而成的化合物。而层间作用力为一种弱作用力,因此LDHs展现出了优秀的层间阴离子交换能力。由于类水滑石的阴离子可交换性和生物相容性使他们能够插入具有高载荷能力阴离子活性分子,这在药物输送方面有很好的应用。另外,因为LDHs层板间金属离子的可调性,可以在晶体结构中掺杂一些功能性离子,例如稀土金属离子,使其材料带有荧光性能。目前,应用LDHs作为一种吸附剂选择性吸附阴离子环境污染物已经引起极大的关注。另外LDHs还可以作为一种优秀的半导体载体,在其表面负载上AgX(X=Br,Cl)和Ag3PO4等半导体。把这种复合材料应用到环境中可以达到吸附和降解污染物的双重效果。本文以LDHs为模板,利用其阴离子交换能力和层板间金属离子的可调性,分别合成了纳米Ag和万古霉素,AgCl,Ag3PO4和Eu2+掺杂的复合材料,并将其应用于荧光标记和杀灭细菌,光催化降解环境有机污染物。具体工作主要分为以下三个方面:(1)以Zn-Al LDHs纳米片为基底材料,通过葡萄糖还原Ag+和阴离子交换法,成功在Zn-Al LDHs表面上修饰上纳米银和万古霉素分子;所制备的万古霉素和纳米银修饰的类水滑石纳米片不仅对细菌具有选择性吸附富集,而且还具有很好的杀菌性能。对所得产物用透射电子显微镜,EDS能谱,FT-IR光谱进行表征。结果表明,30纳米的银颗粒及万古霉素分子均匀的附着在类水滑石层状结构的表面上。由于它们的特性,复合材料可以同时有效的捕获和杀灭细菌。与LDHs,Van/LDHs,Ag/LDHs对大肠杆菌(革兰氏阴性菌)和金黄色葡萄球菌(革兰氏阳性菌)杀菌性能比较,Van-Ag/LDHs表现出更优异的杀菌性能。结合上Van和Ag的LDHs复合材料克服了万古霉素只对阳性细菌具有杀菌作用和纳米银分散性、稳定性差的缺点。合成的纳米复合材料在灭菌方面具有广泛的应用前景。(2)通过两步合成法成功制备了Van和TA修饰的Eu掺杂的LDHs复合材料。首先,通过阴离子交换法制备了对苯二甲酸钠改性的铕掺杂Zn-Al LDHs,然后再在材料表面修饰上能够识别捕获细菌的万古霉素分子。对所得产物用X射线粉末衍射,高分辨透射显微镜,傅里叶变换红外光谱,荧光光谱进行了表征。结果表明万古霉素改性的铕掺杂类水滑石纳米片层材料的粒径在50 nm左右而且材料具有较好的荧光性能。由于万古霉素分子对细菌的识别捕获能力,Van和TA修饰的铕掺杂的类水滑石展现出了较好的荧光标记细菌性能。因此,Van-TA-Eu-LDHs复合纳米材料可能在生物领域如生物分子标记和细胞成像方面有广泛的应用。(3)通过核壳结构的设计,成功合成了一种新型的可见光催化剂Fe3O4@LDHs@Ag/Ag3PO4。以层间插入PO43-的LDHs磁性微球作为媒介,然后再在Fe3O4@LDHs上面合成Ag3PO4纳米颗粒。对所得产物用X射线粉末衍射,X射线光电子能谱,电感耦合等离子体原子发射光谱,高分辨率透射电镜,场发射扫描电子显微镜进行了表征。实验结果表明,LDHs和Ag/Ag3PO4纳米材料成功包覆到Fe3O4表面上。其中,在Fe3O4@LDHs表面上合成Ag/Ag3PO4过程中,PO43-插层的LDHs起到了重要的作用。通过光催化降解有机染料亚甲基蓝的实验表明,在可见光的激发下,光催化剂Fe3O4@LDH@Ag/Ag3PO4对有机污染物具有优异的光催化降解性能,并且利用复合材料中Fe3O4的磁性特征,通过外加磁场的方式从废水中回收复合材料。制备的Fe3O4@LDHs@Ag3PO4/Ag是一种性能优异可回收的复合光催剂。
[Abstract]:Layered Double Hydroxides (LDHs), due to its special layered structure, has aroused great interest in catalysis, photocatalysis, adsorption, electrochemistry, and biotechnology. As an inorganic layered material, LDHs is a compound of interlayer anions and positive charge laminates. The interlayer force is a kind of compound. Weak forces, so LDHs shows excellent interlayer anion exchange ability. Because of the anion exchangeability and biocompatibility of the hydrotalcite, they can insert high load capacity anionic active molecules, which have good application in drug delivery. In addition, because of the tunability of LDHs interplate metal ions, it can be used. The crystal structure is doped with some functional ions, such as rare earth metal ions, which make the materials with fluorescent properties. At present, the application of LDHs as an adsorbent to selectively adsorb anionic environmental pollutants has attracted great attention. In addition, LDHs can also be used as an excellent semi conductor carrier, AgX (X=Br, Cl) and Ag3 on its surface load. PO4 and other semiconductors. The application of this composite material to the environment can achieve the dual effect of adsorption and degradation of pollutants. In this paper, the composite materials of nano Ag and vancomycin, vancomycin, AgCl, Ag3PO4 and Eu2+ are synthesized by using LDHs as a template, and the composite materials are synthesized by the anion exchange capacity and the interlaminar metal ions. Light labeling and killing bacteria and photocatalytic degradation of environmental organic pollutants. The main work is divided into three aspects: (1) the nano silver and vancomycin are successfully modified on the surface of Zn-Al LDHs by glucose reduction Ag+ and anion exchange method, with Zn-Al LDHs nanoscale as the base material; and the prepared vancomycin and nanosilver are prepared. The ornament hydrotalcite nanoparticles not only have selective adsorption and enrichment, but also have good bactericidal properties. The obtained products are characterized by transmission electron microscopy, EDS spectrum and FT-IR spectra. The results show that the 30 nanometer silver particles and vancomycin molecules are uniformly attached to the surface of the layered structure of hydrotalcite. Compared with LDHs, Van/LDHs, Ag/LDHs for the bactericidal performance of Escherichia coli (Gram-negative bacteria) and Staphylococcus aureus (Gram-positive bacteria), Van-Ag/LDHs showed better bactericidal performance compared with LDHs, Van/LDHs, and Staphylococcus aureus (Gram-positive bacteria). The LDHs composite on Van and Ag overcame vancomycin only against the bactericidal performance. The positive bacteria have the disadvantages of bactericidal action and dispersion of nano silver and poor stability. The synthesized nanocomposites have extensive application prospects in sterilization. (2) the LDHs composite doped with Van and TA modified by Eu was successfully prepared by two step synthesis. The Zn-Al LDHs is doped and then the vancomycin molecules can be identified on the surface of the material. The obtained products are characterized by X ray powder diffraction, high resolution transmission microscopy, Fourier transform infrared spectroscopy, and fluorescence spectra. The results show that the particle size of the vancomycin modified europium doped hydrotalcite nanomaterials is in the particle size. It is about 50 nm and the material has good fluorescent properties. The Van and TA modified europium like hydrotalcite exhibits better fluorescent labeling bacteria because of the ability of vancomycin molecules to identify bacteria. Therefore, Van-TA-Eu-LDHs composite nanomaterials may have a biological domain, such as biomolecular markers and cell imaging. 3. (3) through the design of nuclear shell structure, a new type of visible light catalyst Fe3O4@LDHs@Ag/Ag3PO4. was successfully synthesized by inserting PO43- LDHs magnetic microspheres between layers as medium, and then synthesizing Ag3PO4 nanoparticles on Fe3O4@LDHs. The obtained products were diffracted by X ray powder, X ray photoelectron spectroscopy, inductively coupled and so on. The plasma atomic emission spectroscopy, high resolution transmission electron microscopy, and field emission scanning electron microscopy were characterized. The results showed that the LDHs and Ag/Ag3PO4 nanomaterials were successfully coated on the Fe3O4 surface. In the process of synthesizing Ag/Ag3PO4 on the Fe3O4@LDHs surface, the PO43- intercalated LDHs played an important role. The photocatalytic degradation was achieved by photocatalytic degradation. The experimental dye methylene blue experiment shows that the photocatalyst Fe3O4@LDH@Ag/Ag3PO4 has excellent photocatalytic degradation performance on organic pollutants under the excitation of visible light, and uses the magnetic properties of Fe3O4 in the composite material to recover the composite materials from the wastewater by the external magnetic field. The prepared Fe3O4@LDHs@Ag3PO4/Ag is a kind of performance. Excellent recoverable compound light accelerating agent.
【学位授予单位】：山东农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB33;O643.36

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