Scanning force microscopy for high-resolution imaging of solid-liquid interfaces

用于固液界面高分辨率成像的扫描力显微镜

• 批准号: 420771391
• 金额: --
• 依托单位: Universität Bielefeld
• 依托单位国家: 德国
• 项目类别: Major Research Instrumentation
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 无数据
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/420771391?language=en
• 关键词: Scanning; force; microscopy; resolution; imaging

With this proposal, we apply for a scanning force microscope to study solid-liquid interfaces with high spatial resolution. A key aspect of the present proposal is based on an instrumental improvement that enables mapping of a three-dimensional volume at the interface rather than collecting conventional (two-dimensional) images. This method provides insights into structural changes vertical to the surface, which is highly interesting for studying the solvation structure at an interface in real space and at the molecular scale.The ability to image the solvation structure at an interface is pivotal to address fundamental research topics. As an example, the specific binding situation of ions at the interface is usually unknown: Do ions bind directly to the surface or do they remain entirely hydrated? What is the impact of ions on the hydration structure at the interface? Does this effect depend on the specific nature of the ions and / or the surface? The interface defines the interaction with the environment, thus, these questions are fundamental to a wide range of fields including, e.g., geochemistry, biomineralization and electrochemistry.A special focus will be put on graphite-water interfaces as they are important model systems for studying molecular self-assembly. Interestingly, the role of the solvent is often neglected in these studies, although the hydration of both the surface and the molecules is expected to have an impact on the self-assembly process. Moreover, several studies have reported the formation of ordered stripes at the graphite-water interface. The origin of these stripes is, however, discussed controversially. To shed light on the nature of these stripes, it is important to precisely control experimental conditions such as the surrounding gas atmosphere and temperature, which is possible with the instrument applied for in the proposal.While flat surfaces are ideal for high-resolution scanning force microscopy investigations, step edges represent decisive sites in terms of reactivity. Achieving atomic resolution at step edges is experimentally very challenging, but surely required for arriving at an in-depth understanding of processes such as molecule adsorption as well as crystal growth and dissolution. Pushing the limits of high-resolution scanning force microscopy has now opened up the possibility of atomic resolution imaging of step edges. Using three-dimensional scanning force microscopy, we aim for mapping the solvation structure at step edges and unraveling the reactivity of these sites.

在此基础上，我们应用了扫描力显微镜来研究高空间分辨率的固液界面。本方案的一个关键方面是基于一种仪器改进，其使得能够在界面处绘制三维体积，而不是收集常规(二维)图像。这种方法提供了垂直于表面的结构变化的洞察，这对于在真实空间和分子尺度上研究界面上的溶剂化结构是非常有趣的。成像界面上的溶剂化结构的能力对于解决基础研究课题至关重要。例如，离子在界面上的具体结合情况通常是未知的：离子是直接结合到表面还是保持完全水合？离子对界面的水化结构有什么影响？这种效应是否取决于离子和/或表面的特定性质？界面定义了与环境的相互作用，因此，这些问题是包括地球化学、生物矿化和电化学在内的广泛领域的基础。将特别关注石墨-水界面，因为它们是研究分子自组装的重要模型系统。有趣的是，在这些研究中，溶剂的作用往往被忽略，尽管表面和分子的水合预计会对自组装过程产生影响。此外，一些研究已经报道了在石墨-水界面上形成有序条纹。然而，这些条纹的起源是有争议的。为了阐明这些条纹的性质，重要的是要精确地控制实验条件，如周围的气体大气和温度，这可以用提议中应用的仪器来实现。虽然平坦的表面是高分辨率扫描力显微镜研究的理想选择，但台阶边缘在反应性方面代表着决定性的位置。在阶梯边缘实现原子分辨率在实验上是非常具有挑战性的，但对于深入理解分子吸附以及晶体生长和溶解等过程肯定是必要的。突破高分辨率扫描力显微镜的极限，现在已经打开了对台阶边缘进行原子分辨率成像的可能性。使用三维扫描力显微镜，我们的目标是绘制阶跃边缘的溶剂化结构图，并解开这些位置的反应性。