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目前和新兴的技术和消费应用是至关重要的。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，通常也是从水溶液中生产出来的。因此，在分子水平上全面了解金属氧化物/水的相互作用对于设计具有理想性能的氧化物和确保这些材料随时间的稳定性(即抗降解和耐腐蚀)是必不可少的，但目前还没有达到这一点。它需要合作研究努力，并考虑到大量关于水的数量和氧化物的复杂性，范围从单个分子、团簇和纳米颗粒到扩展的晶体和非晶体材料。金属氧化物/水化学的这种深刻的多尺度性质带来了重大挑战--也是在方法上--我们的CRC接受了这种挑战，并将重点放在某些具有代表性的氧化物上，目的是完整地描述CRC运行时的形成和溶解过程。为了研究氧化物组装和溶解的不同阶段，CRC结合了最先进的理论、化学合成、显微镜和光谱分析方法，包括时间分辨原位光谱分析。在第一个资助期，研究中心重点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、缺陷位置的产生和行为、成核和结晶，以及评估分子化合物和二维薄膜作为更多聚集结构模型的潜力。在第二个资助期，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的金属氧化物结构(分子、团簇、表面台阶)的形成和溶解机制的理解。非局域效应将被明确考虑，在氧化物一侧将包括相变和电子结构随尺寸的发展。在水方面，将通过在表面研究中增加水分子的数量以及探索溶质离子的影响来考虑这些影响，从而加强与自然系统的联系。为了达到我们的目标，我们方法的进一步发展也将发挥重要作用。《儿童权利公约》显然着眼于基本的见解。然而，所获得的知识也将为按需合理合成具有预定性质的金属氧化物铺平道路，并为获得成分或结构新颖的材料提供途径。

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.