Chemical design and chemical process for functional ceramics using ionomers

本工作的核心是制备均匀的多组分凝胶前驱体，用于在降低的温度下合成各种先进的陶瓷材料。为了实现这一目标，从与各种溶剂中金属螯合物形成密切相关的溶液化学的基本方面到包括凝胶科学领域在内的聚合物科学，已经系统地进行了许多方面的研究。特别重要的是如何制备具有所需化学计量比的杂金属络合物作为陶瓷材料的合适分子前体。使用包括拉曼、红外和NMR的各种光谱技术作为工具，以深入了解在起始溶液或聚合产物中形成的分子种类或键合类型。工作的另一个重要部分是研究凝胶前体在热处理过程中结构的演变。这也是使用上面列出的光谱技术完成的 关于我们 iques以及X射线衍射技术。1）在不同的M-Ti-柠檬酸（CA）体系中设计了不同的金属配合物，其中M=Ba，Sr，Pb和Y，建立了一种用~ 1H-NMR谱鉴定溶液中金属配合物的方法<13>。在这些配合物的存在下，乙二醇与CA发生聚酯化反应，以获得均匀的多组分凝胶。2）利用拉曼和核磁共振谱研究了多组分陶瓷的结构演变。主要通过拉曼散射和X射线衍射技术对最终产物进行表征。3）总体结果：建立了一种制备均相多组分凝胶前驱体的方法，该方法可用于在低温下合成高纯度的多组分陶瓷。少

Central in the present work is to prepare homogeneous multicomponent gel precursors for the synthesis of various advanced ceramic materials at reduced temperatures. To reach this goal, studies under the many aspects ranging from the basic aspects of the solution chemistry closely connected to metal-chelate complex formations in various solvents to the polymer science including the field of the gel science have been systematically carried out. Of particular importance is how to prepare hetero-metallic complexes with a desired stoichiometry as a suitable molecular precursor for ceramic materials. Various spectroscopic techniques involving Raman, infrared and NMR were used as tools to gain insight into molecular species or bonding type that are formed either in a starting solution or in a polymeric product. Another important part of the work is to study the evolution of structure during the heat treatment of the gel precursors. This also was done using the above listed spectroscopic techn … More iques as well as X-ray diffraction techniques. The main results obtained were summarized as below :1) Heterometallic complexes were designed in various M-Ti-citric acid (CA) systems, where M=Ba, Sr, Pb, and Y.A unique method for the identification of heterometallic complexes in solutions was established by employing ^<13>C-NMR spectroscopy. Polyesterification between ethyleneglycol and CA was carried out in the presence of these complexes in order to obtain homogeneous multi-component gels.2) Structural evolution of multi-component ceramics was studied by use of Raman and NMR spectroscopies. Characterization of the final product was developed mainly by Raman scattering and X-ray diffraction techniques. Particular attention was paid to determining conditions of reducing the synthesis temperatures.3) Overall outcome : A scheme to prepare homogeneous multicomponent gel precursors, that can be used for the high-pure synthesis of multi-component ceramics at reduced temperatures was built up. Less