【作者】 从怀萍；

【导师】 俞书宏；

【作者基本信息】 中国科学技术大学 ， 无机化学， 2008， 博士

【摘要】 本论文将传统的在二元体系混合溶剂中合成无机晶体的方法引入到控制有机晶体的生长中,并进一步拓展到制备有机/无机复合材料的体系中去。将传统的水热技术和矿化过程相结合制备了一系列不同结构的碳酸钴和多孔氧化钴晶体。利用简单的重结晶方法很好地控制了有机染料晶体的形貌和生长过程。通过对无机材料和有机染料生长习性的摸索,利用简单的一步溶液相反应和不同的染料前驱体成功地构造了多彩的氧化锌/染料复合材料。通过引入生物小分子-苯丙氨酸到复合材料的制备体系中,合成了具有新颖结构和独特荧光性质的苯丙氨酸锌/染料复合材料。研究结果发现,材料的性质和功能不仅与其组份有着重要的关系,还与它的微观形貌和尺寸有着密切联系。1.160℃,利用醋酸钴和碳酸氢铵在水热条件下反应合成了碳酸钴。通过改变二元混合体系中水和乙醇(或丙三醇)的体积比制备出了不同形貌和结构的碳酸钴晶体,诸如球状、花状、哑铃状、花生状以及棒状等。在水和乙醇体系中,晶体的成核和生长过程通过“溶解-再成核”和聚集机理得到合理解释;而从水和丙三醇体系中合成的晶体的形貌变化符合经典的“棒-哑铃-球”演变过程。通过煅烧碳酸钴得到多孔的氧化钴晶体,而产物的形貌保持不变。在气敏性能的测试中,这些氧化钴具有很高的敏感性和良好的重复性。2.系统地研究了染料酸性绿27(AG27)在乙醇(甲醇)和水的二元混合溶剂中在80℃下的重结晶状况。结果表明AG27晶体的尺寸和形貌能够通过简单地改变醇和水的体积比而得到调控。实验中能选择性地合成出棒状和梭状的染料晶体。XRD数据结果分析显示有机晶体具有周期性结构。通过晶体生长的热力学和动力学研究分析了溶剂对晶体形貌和尺寸的影响。3.利用简单的一步合成过程制备了具有新型光学性质的氧化锌/染料复合材料。当使用伊文思蓝(EB)作为染料前驱体时,EB和十六烷基三甲基溴化铵(CTAB)通过离子自组装作用形成了CTAB-EB复合胶束。在温和回流条件下,当反应体系中加入了醋酸锌和氨水后,这种胶束对ZnO/EB复合空心球的形成起到了软模板作用。当染料前驱体是酸性绿27(AG27)时,在不添加任何表面活性剂的条件下,通过改变染料的使用量控制合成了一系列具有新颖形貌和可调光学性质的ZnO/AG27二元复合物和ZnO/AG27/Zn-AG27三元复合物。当染料AG27的用量由15mg变化到2mg时,复合材料中位于766nm处的染料近红外发光峰从747nm蓝移到717nm。4.通过简单的一步回流反应成功地合成了筏状的苯丙氨酸锌配合物以及苯丙氨酸锌/酸性绿27(AG27)束状复合材料。基于反应产物随时间的演变过程,提出了束状复合物的形貌和结构的形成机理。AG27分子在最终复合物的形貌和结构的形成过程中起到了掺杂组分和控制剂的作用。更多还原

【Abstract】 In this dissertation,new strategies for synthesizing inorganic materials in mixed solvents have been developed to synthesize organic crystals and inorganic/organic materials with novel morphologies and hierarchical microstructures.Cobalt carbonate as a kind of the important inorganic mineral models has been selected to investigate the growth-controlled process of crystals in the mixed solvent system.A series of cobalt carbonate particles with different shapes have been prepared by the combination of classical hydrothermal method and mineralization process,which can be calcined into nanoporous cobalt oxide crystals.Then,the mixed-solvent strategy has been successfully extended to the controlled crystallization of organic materials. The shape and growth process of the organic dye crystals can be well controlled by the simple recrystallization method.Based on understanding on the growth habit of inorganic and organic materials,the colorful zinc oxide/dye hybrids have been prepared by a simple one-step solution process.In addition,the phenylalanine-zinc/dye hybrid bundles with novel structures and new optical properties have been synthesized by introducing amino acid into hybrid system.The functionalities of materials not only depend on their compositions,but also on the shapes and microstructures.1.Cobalt carbonate crystals with different shapes,such as microspheres,flowers, dumbbells,peanuts,rods ere,have been successfully synthesized by the hydrothermal reaction of cobalt acetate and ammonium hydrogen carbonate at 160℃,which are achieved via tuning the volume ratios of the mixed solvents of water and ethanol（or glycerol）.The growth and nucleation mechanism of CoCO₃ crystals in the mixtures of water and ethanol can be illuminated by dissolution-renucleation process and aggregate-based mechanism;while the shape transitions of the particles in the water-glycerol system are well consistent with the "rod-dumbbell-sphere" morphogenesis mechanism.The nanoporous cobalt oxides with unchanged shapes can be obtained by the calcination of CoCO₃ precursors.The nanoporous Co₃O₄ particles show sensitive response and reversibility in sensing performances.2.The shapes and sizes of dye acid green 27（AG27） can be controlled via tuning the volume ratios of ethanol（or methanol） and water in the mixed solvents by recrystallization method at 80℃.Rodlike and shuttlelike AG27 crystals can be selectively synthesized.The XRD analyses reveal the periodic structures of the organic crystals.The growth mechanism is investigated from the viewpoint of thermodynamics and kinetics.3.Colorful ZnO/dye hybrid functional materials with new optical properties have been synthesized through self-assembly process.It is found that various dyes can be incorporated into ZnO and form hybrids with unique morphologies and novel properties by the similar method.A synergetic-template effect,generated by the interaction between surfactants and dye molecules through ionic self-assembly,has been proposed.4.The raft-like phenylalanine-zinc complexes and phenylalanine-zinc/dye hybrid bundles with new optical properties have been fabricated from the water-ethanol mixed solvents.A principle of classical electric line in the mineralization process directing alignment of phenylalanine-zinc/dye bundles is illuminated.Systematically,dye molecules play crucial roles in the formation of functional inorganic-organic hybrid materials.They are the controller of shapes and properties of the hybrid composites,as well as the inclusive components.更多还原