基于分级结构铝基LDHs复合材料的可控制备及其性能研究

发布时间：2018-06-22 05:08

  本文选题：LDHs + 分级结构　； 参考：《东南大学》2015年博士论文

【摘要】：结构功能一体化的功能复合材料是目前材料物理与化学领域的一个重要研究方向。作为一种重要的功能材料,层状双金属氢氧化物(LDHs)独特的片状结构、可调的结构与组分、良好的生物兼容性,使其在污染控制、化工分离、光电材料、生物材料和催化材料等领域得到广泛的研究和应用。目前,基于二维纳米片多功能器件的设计、组装和集成已成为研究者关注的焦点,特别是功能石墨烯复合材料的发展,迫切需要我们从宏观到微观设计多功能LDHs基复合材料,并研究其相关性能。然而,由于LDHs特殊的二维结构,如何在微/纳米尺度下实现对LDHs基复合材料的结构控制和组分优化,进而实现对其物理和化学性能可控调变仍是一个极具挑战性的工作。分级结构的功能材料的可控合成已成为国内外研究的热点,它对于光学、吸附、催化和分离等以界面现象为主的应用有着重要的研究意义。这种材料在连续的微、纳米尺度范围下具有二重或者多重形态结构并呈现多层次分布,其特有的结构和形貌使其具有独特的物理化学性能。分级结构LDHs基复合材料由于具有纳米尺度的二维片状结构单元和亚微米及以上尺度的整体形貌,以及不同结构之间的协同和耦合效应,使其具有特殊表面性能。设计分级结构LDHs基复合材料,可有效防止LDHs纳米片在液相中团聚问题,改善LDHs粉体在生产和应用时难分离和回收问题,同时,增强材料的机械性能。材料的结构功能一体化体现了结构与功能之间的耦合关系,说明可以通过对材料微结构的设计和优化来调变材料的性能。本论文紧密跟踪当前层状材料研究动向,结合生物模板法和原位生长技术设计生物形态分级结构LDHs基复合材料,系统的研究了材料的制备工艺、化学组分、微结构及其耦合效应对材料性能的影响,并探讨多相LDHs基复合材料组分-工艺-微结构-性能之间的关系。主要研究工作和内容如下：1.利用原位生长技术,在基体铝片上定向生长LDHs薄膜,并考察薄膜的红外辐射性能。通过控制水热温度和时间获得系列形貌和微结构渐变的LDHs。根据薄膜材料的微结构变化控制其红外吸收和红外反射,进而控制LDHs薄膜的红外辐射性能。由于所制备的LDHs薄膜具有可调的形貌和结构,拥有可控的红外发射率性能,使其在低红外发射率材料和热控制方面都具有潜在的应用价值。该研究不仅为设计分级结构的LDHs基复合材料提了供理论基础,而且拓展了LDHs材料在吸波方面的应用。2.以Zn-Al LDHs层板金属为基础,设计分级结构的ZnO和Al2O3纤维。为了获得微/纳分级结构的ZnO,首先在脱脂棉纤维表面植入ZnO晶种,再采用硝酸锌/六次亚甲基四胺体系在纤维表面原位生长ZnO纳米棒,从而制备微/纳分级结构的ZnO纤维。通过模板法,制备生物形态的Al2O3纤维,以Al2O3纤维为骨架,通过水热反应,在其表面生长一层AlOOH纳米颗粒,再通过焙烧处理获得分级结构的Al2O3纤维。所提供的分级结构氧化物纤维的制备方法具有工艺简单和成本低廉等特点,所制备生物形态的功能氧化物在吸附、催化、光学和电子等领域有着潜在应用价值。3.以Zn-Al LDHs层板金属为基础,设计分级结构的LDHs/ZnO复合材料。该方法基于在脱脂棉纤维表面原位生长LDHs纳米片；通过去除生物模板,使所制备的复合材料具有微/纳分级结构。该合成路线不仅能获得生物形态的LDHs复合材料,同时能避开传统方法剥离LDHs存在的污染问题。由于LDHs纳米片与牛血清白蛋白(BSA)表面有机官能团之间的静电引力,以及复合材料独特的表面结构,所制备的复合材料有着良好的BSA分离性能。4. 以Zn-Al LDHs层板金属为基础,设计多组分ZnO/LDHs/Al2O3复合材料。以Al2O3纤维为基体和铝源,硝酸锌/六次亚甲基四胺为水热体系,通过调变实验条件,控制LDHs晶体生长和锌盐水解,制备生物形态ZnO/LDHs/Al2O3复合材料,并对复合材料的组分进行优化。以Mg-Al LDHs层板金属为基础,硫酸镁/尿素为水热体系,通过控制LDHs纳米晶生长热力学和动力学,对所制备的LDHs/Al2O3复合材料结构进行优化。优化后的复合材料具有独特的微/纳结构、较高的比较面积和较大的孔容。与焙烧LDHs/ZnO复合材料相比,结构优化的LDHs/Al2O3复合材料的比表面积由42.32m2/g增加到292.51m2/g,优化后的复合材料对BSA的吸附性能也进一步增强。5.以Zn-Al LDHs层板金属为基础,制备BSA/ZnO和BSA/LDHs杂化材料。利用静电引力将Zn2+吸附到BSA表面,并在BSA表面发生水解,形成ZnO/BSA纳米颗粒；在晶体驱动力的作用下,ZnO/BSA纳米颗粒进一步自组装成花状结构。所制备的BSA/LDHs杂化材料,不仅具有良好的生物兼容性,还具有良好的光学性能。利用BSA和金属铝离子之间的静电引力,将BSA和与铝溶胶组装成BSA/铝溶胶；采用原位生长技术,以BSA表面的铝溶胶为铝源,在其表面原位生长LDHs,从而制备BSA/LDHs杂化材料。所制备的杂化材料在生物分离、催化、吸附、传感和光学等领域有着潜在的应用前景。总之,本论文致力于将生物结构和生物功能引入到LDHs中,来改善LDHs基复合材料的表面性能和开发多层次、多维度乃至结构功能一体化的功能复合材料。通过本文研究,有助于揭示LDHs纳米片与生物材料之间的界面作用和LDHs纳米片原位生长机理,为更深入地研究其它层状材料的结构设计和组装提供了新的研究途径。对于有效控制材料的结构和形貌提供实验基础和理论依据,同时也推动其他复合材料的发展,深化材料的应用。
[Abstract]:Functional composite material with functional integration is an important research direction in the field of material physics and chemistry. As an important functional material, layered double metal hydroxide (LDHs) is unique flaky structure, adjustable structure and component, good biocompatibility, and makes it in pollution control, chemical separation, photoelectric materials, biology. The research and application of materials and catalytic materials have been widely studied. At present, the design, assembly and integration of multi-functional devices based on two-dimensional nanometers have become the focus of attention, especially the development of functional graphene composites. It is urgent for us to design multi-functional LDHs based composites from macro to microcosmic and to study their correlation. However, because of the special two-dimensional structure of LDHs, it is still a challenging task to realize the structure control and component optimization of LDHs based composites at the micro / nanoscale, and to realize the controllable modulation of physical and chemical properties. The controllable synthesis of functional materials of the hierarchical structure has become a hot spot at home and abroad. It has important research significance for the applications of optical, adsorption, catalysis and separation as the main interface phenomena. This material has two or multiple morphological structures and multilayered distribution under continuous micro and nanometer scale, and its unique structure and morphology make it have unique physical and chemical properties. The graded structure LDHs matrix complex The composite materials have special surface properties due to the nanoscale two-dimensional sheet structure units and the overall morphology of sub micrometers and above scales, as well as the synergistic and coupling effects between different structures. The design of LDHs based composite materials with hierarchical structure can effectively prevent the agglomeration of LDHs nanoscale in liquid phase, and improve the production of LDHs powder in the production. It is difficult to separate and recover the problem, at the same time, the mechanical properties of the material are enhanced. The integration of the structure and function of the material reflects the coupling relationship between the structure and the function. It shows that the material can be adjusted by the design and optimization of the material microstructure. This paper closely tracks the current research trend of the layered materials and combines the biological template. LDHs based composite materials were designed by method and in situ growth technology. The preparation process, chemical composition, microstructure and coupling effect on material properties were systematically studied. The relationship between the composition of multiphase LDHs based composites - Process Microstructures and properties was discussed. The main research work and content were as follows: 1. In situ growth technology was used to orientate the LDHs film on the matrix aluminum sheet, and the infrared radiation properties of the film were investigated. The infrared absorption and infrared reaction of the films were controlled by the microstructural changes of the LDHs. film materials by controlling the temperature and time of the hydrothermal process. The infrared radiation properties of the LDHs films were controlled. Due to the adjustable morphology and structure of the prepared LDHs films and the controllable infrared emissivity, it has potential application value in low infrared emissivity materials and heat control. This study not only provides a theoretical basis for the design of LDHs based composites with hierarchical structure, but also expands the absorption of LDHs materials in the wave absorption. Based on the Zn-Al LDHs laminates,.2. is used to design a hierarchical structure of ZnO and Al2O3 fibers. In order to obtain the ZnO of the micro / nanoscale structure, the ZnO crystal is first implanted on the surface of the skimmed cotton fiber, and then zinc nitrate / six methylene four amine system is used to grow ZnO nanoscale on the surface of the fiber on the surface of the fiber, thus the micro / nano structured ZnO fiber is prepared. By template method, the Al2O3 fiber of biological form is prepared, with Al2O3 fiber as the skeleton, a layer of AlOOH nanoparticles is grown on the surface by hydrothermal reaction, and then the graded structure of Al2O3 fiber is obtained by roasting. The preparation method of the graded structure oxide fiber has the characteristics of simple process and low cost. Functional oxides of substance form have potential application value in the fields of adsorption, catalysis, optics and electronics, which are based on the Zn-Al LDHs laminate metal as the basis for the design of a hierarchical structure of LDHs/ZnO composite. This method is based on the growth of LDHs nanoscale in situ on the surface of the skimmed cotton fiber; by removing the biological template, the composite materials are prepared by.3.. Micro / nanoscale structure. The synthetic route not only can obtain biological morphology of LDHs composite, but also avoid the traditional method of stripping the existing pollution problems of LDHs. The composite materials are prepared by the electrostatic attraction between LDHs nanoscale and bovine serum albumin (BSA) surface organic functional groups and the unique surface structure of the composite. Good BSA separation performance.4. is based on Zn-Al LDHs laminates to design multi component ZnO/LDHs/Al2O3 composites. Using Al2O3 fiber as the matrix and aluminum source, zinc nitrate / six methylene four amine as hydrothermal system, by adjusting the experimental conditions, controlling the growth of LDHs crystal and the hydrolysis of zinc salt, and preparing the bioform ZnO/LDHs/Al2O3 composite material. The composition of the composite is optimized. Based on Mg-Al LDHs laminates, Magnesium Sulfate / urea is a hydrothermal system. By controlling the thermodynamics and dynamics of LDHs nanocrystalline growth, the structure of the prepared LDHs/Al2O3 composite is optimized. The optimized composite has a unique micro / nano structure, a higher comparison area and a larger hole. Compared with the calcined LDHs/ZnO composite, the specific surface area of the structure optimized LDHs/Al2O3 composite is increased from 42.32m2/g to 292.51m2/g. The adsorption properties of the composite material to BSA are further enhanced by.5., based on Zn-Al LDHs laminates, BSA/ZnO and BSA/LDHs hybrid materials are prepared. Zn2+ adsorption to BSA by electrostatic force is used. On the surface, the surface of the BSA is hydrolyzed to form ZnO/BSA nanoparticles, and the ZnO/BSA nanoparticles are further self assembled into flower like structures under the action of crystal driving force. The prepared BSA/LDHs hybrid materials not only have good biocompatibility, but also have good optical energy. The electrostatic attraction between BSA and metal aluminum ions is used. BSA and aluminum sol are assembled into BSA/ aluminum sol; in situ growth technology, aluminum sol on the surface of BSA is used as aluminum source, and LDHs is grown on its surface in situ, thus preparing BSA/LDHs hybrid materials. The prepared hybrid materials have potential applications in biological separation, catalysis, adsorption, sensing and optical domains. In a word, this paper is devoted to the research. The biological structure and biological function are introduced into LDHs to improve the surface properties of LDHs based composites and to develop functional composites with multi-layer, multi-dimensional and even structural functions. Through this study, it is helpful to reveal the interface between the LDHs nanoscale and the biomaterials and the mechanism of the in situ growth of the LDHs nanoscale. It provides a new way to study the structural design and assembly of other layered materials. It provides an experimental basis and theoretical basis for the effective control of the structure and morphology of materials, and also promotes the development of other composite materials and deepens the application of materials.
【学位授予单位】：东南大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TB33
，

本文编号：2051714