Probing nanoscale interactions at the solid-liquid interface via liquid-phase electron microscopy

通过液相电子显微镜探测固液界面的纳米级相互作用

• 批准号: 434966740
• 负责人: Professor Dr. Niels De Jonge
• 金额: --
• 依托单位: Leibniz-Institut für Neue Materialien gGmbH (INM)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2020
• 资助国家: 德国
• 起止时间: 2019-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/434966740?language=en
• 关键词: Probing; nanoscale; interactions; solid; liquid

The interactions between nanometer-sized objects in liquid environments are key to the functioning of a variety of applications based on colloidal systems, self-assembly processes, diffusive motion at interfaces, for example, in energy-storage materials, and are also of relevance for understanding processes in biology involved in the molecular machinery of life. The true situation at the nanoscale is typically far from symmetric, leading to a high complexity of the potentials so that the basic understanding of the physical rules governing spatial organization at the nanoscale is still incomplete and unexpected/special phenomena continue to be discovered. The overall goal of this project is to study dynamic nanoparticle behavior at the solid-liquid interface. Recent advances in in situ liquid-phase electron microscopy made it possible to directly image nanoparticle movement at the nanoscale. Using this new “viewing window”, we and others have discovered an unexpected exceptional slow movement of gold nanoparticles in liquid, three orders of magnitude slower than predicted on the basis of Brownian motion. The underlying mechanism is possibly of key importance for a correct description of dynamic interactions at the solid-liquid interface. One possible mechanism is that an ordered liquid layer leads to super-viscosity thus slowing down the nanoparticle motions. The research plan entails the following four work packages:WP 1: Establish Liquid STEM of nanoparticle movement. The proposed research will start out by establishing and optimizing the experimental conditions for observing slow movement of different types of nanoparticles in liquid. The specifications of the nanoparticles will be tested and the effect of the density of the electron beam will be evaluated. WP 2: Investigation of Brownian motion. The movement of nanoparticles will be examined for the characteristics of Brownian motion in which the mean square displacement MSD scales linear with time and a scaling law applies with the temperature, and the nanoparticle radius. Several parameters will be varied and translational movements will be analyzed. WP 3: Investigation of other mechanisms of motion. We will also test the presence of other possible mechanisms in which the motion will be driven or partly driven, for example, by a stick-and-slip mechanism or electrostatic hindrance. We will also examine rotational movements.WP 4: Study long-range ordered liquid layer. Finally, we will investigate the anticipated presence of a long-range ordered liquid layer extending out several tens of nanometers from the solid-liquid interface, and exhibiting an exceptionally high viscosity. The interface liquid layer will also be examined with atomic force microscopy as alternative experimental method.

在液体环境中的纳米大小的物体之间的相互作用是关键的各种应用程序的功能基于胶体系统，自组装过程，在界面处的扩散运动，例如，在能量存储材料，也是相关的理解过程中的生物学参与的分子机械的生命。在纳米尺度下的真实情况通常是远离对称的，导致电位的高度复杂性，使得对纳米尺度下控制空间组织的物理规则的基本理解仍然不完整，并且继续发现意想不到的/特殊的现象。该项目的总体目标是研究纳米粒子在固液界面的动态行为。原位液相电子显微镜的最新进展使得直接成像纳米颗粒在纳米尺度上的运动成为可能。使用这种新的“观察窗”，我们和其他人发现了金纳米粒子在液体中意外的异常缓慢运动，比布朗运动的基础上预测的慢三个数量级。潜在的机制可能是一个正确的描述在固-液界面的动态相互作用的关键重要性。一种可能的机制是，有序的液体层导致超粘度，从而减缓纳米颗粒的运动。该研究计划包括以下四个工作包：WP 1：建立纳米颗粒运动的液体STEM。这项研究将从建立和优化实验条件开始，以观察不同类型的纳米粒子在液体中的缓慢运动。将测试纳米颗粒的规格，并评估电子束密度的影响。WP 2：布朗运动的研究。将检查纳米颗粒的运动的布朗运动的特征，其中均方位移MSD与时间成线性比例，并且比例定律与温度和纳米颗粒半径一起应用。将改变几个参数，并分析平移运动。WP 3：其他运动机制的研究。我们还将测试是否存在其他可能的机制，在这些机制中，运动将被驱动或部分驱动，例如，由粘滑机制或静电阻碍。我们还将研究旋转运动。WP 4：研究长程有序液体层。最后，我们将研究预期存在的长程有序液体层延伸出几十纳米的固液界面，并表现出非常高的粘度。界面液体层也将用原子力显微镜作为替代实验方法进行检查。