SFB 1109: Understanding of Oxide/Water Systems at the Molecular Scale: Structural Evolution, Interfaces and Dissolution

基于金属氧化物的材料对于许多当前和新兴的技术和消费者应用至关重要。在这些应用中，从医疗植入物到表面涂层和建筑材料，金属氧化物在使用过程中经常与水接触，并且通常它们也由水溶液产生。因此，在分子水平上对金属氧化物/水相互作用的全面理解对于设计具有期望性能的氧化物和确保这些材料随时间的稳定性（即抗降解和抗腐蚀性）是必不可少的，但尚未达到。它需要协同研究工作，考虑到水量和氧化物复杂性的大范围，从单个分子，簇和纳米颗粒到扩展的结晶和非晶块状材料。金属氧化物/水化学的这种深刻的多尺度性质提出了重大挑战-也是方法上的-我们的CRC接受并专注于某些代表性氧化物，旨在CRC运行时间内完整描述形成和溶解过程。为了研究氧化物组装和溶解的不同阶段，CRC采用了理论、化学合成、显微镜和光谱学（包括时间分辨原位光谱学）等最先进方法的组合。在第一个资助期内，CRC专注于研究氧化物形成的初始阶段，模型表面与少量水的相互作用，缺陷部位的产生和行为，成核和结晶，以及分子化合物的潜力评估以及二维薄膜作为更聚集结构的模型。在第二个资助期内，我们将进一步开展这项研究和我们的结果提出的问题，例如，通过调查进一步加深我们对所有长度尺度（分子，簇，表面台阶）的金属氧化物结构形成和溶解机制的理解。非局部效应将被明确考虑，其中在氧化物的一侧将包括相变和电子结构随尺寸的发展。在水方面，这些影响将通过增加表面研究中的水分子数量以及探索溶质离子的影响来考虑，从而加强与自然系统的联系。为了实现我们的目标，我们的方法的进一步发展也将发挥重要作用。《儿童权利公约》显然旨在提出基本见解。然而，所获得的知识也将为按需合理合成具有预定性能的金属氧化物铺平道路，并提供获得成分或结构新颖的材料的途径。

Materials based on metal oxides are of crucial importance for a multitude of present and emerging technical and consumer applications. In such applications, ranging from medical implants to surface coatings and construction materials, metal oxides are very often in contact with water during use and typically they are also produced from aqueous solution. Thus, a comprehensive understanding of the metal oxide/water interactions on the molecular level is indispensable for the design of oxides with desirable properties and for ensuring the stability of these materials over time (i.e. resistance to degradation and corrosion) but is has not been reached yet. It requires collaborative research efforts with consideration of a large width concerning water amount and oxide complexity, ranging from individual molecules, clusters and nanoparticles to extended crystalline and amorphous bulk materials. This profound multi-scale nature of metal oxide/water chemistry poses major challenges - also methodologically - that our CRC accepts and with focus on certain representative oxides aims at a complete description of the formation and dissolution processes within the CRC run-time. To investigate the different stages of oxide assembly and dissolution the CRC employs combinations of state-of-the-art methods in theory, chemical synthesis, microscopy and spectroscopy, including time-resolved in-situ spectroscopy. In the first funding period the CRC has focussed on the investigation of the initial stages of oxide formation, interactions of model surfaces with small amounts of water, the generation and behaviour of defect sites, nucleation and crystallisation, and on the evaluation of the potential of molecular compounds as well as two dimensional films as models for more aggregated structures. In the second funding period we will further pursue this research and issues raised by our results, extending it, for instance, by investigations to further deepen our understanding of the mechanisms by which the structures of metal oxides at all length scales (molecules, clusters, steps on surfaces) are formed and dissolved. Non-local effects will explicitly be considered, which on the side of the oxide will include phase transformation and the development of electronic structure with size. On the side of the water these effects will be considered by increasing the numbers of water molecules in surface studies as well as by exploring the influence of solute ions, thus strengthening the connection to natural systems. To reach our goals, also the further development of our methods will play an important role. The CRC clearly aims at fundamental insights. However, the obtained knowledge will also pave the way for the rational synthesis of metal oxides with predetermined properties on demand and provide access to compositionally or structurally novel materials.