SGER: Characterization of Surface Ionic Activity of Proton Conducting Membranes

本项目将重点利用新型扫描探针显微镜研究膜制备和预处理对质子导电膜表面离子活性和催化活性的影响。PI正在开发的技术包括原子力显微镜，其中电路经过修改以包括电压传感能力。这种双模扫描探针显微镜技术将用于探测暴露于液态水和水蒸气的膜的外表面和外表面孔内的离子团的形貌。以前的尝试是用扫描电化学显微镜扫描膜表面。这项技术依赖于测量表面电化学反应产生的电流；因此，分辨率一直很低。在提出的方法中，PI将尝试测量由铂纳米探针接触离子团簇产生的电位。期望有更高的灵敏度和更高的二维和三维分辨率。如果可以测量离子簇的形貌，就可以量化膜预处理和制造工艺对簇形成的影响。对离子团簇行为的基本理解可能导致燃料电池膜组件的改进。

This project will focus on using a novel scanning probe microscope to study the effects of membrane preparation and pretreatment on the surface ionic and catalytic activities of proton conducting membranes. The technique being developed by the PI consists of an atomic force microscope in which the circuit is modified to include voltage-sensing capability. This dual-mode scanning-probe microscopy technique will be used to probe the topography of ionic clusters on the outer surface and within wells of the outer surface of membranes exposed to both liquid water and water vapor. Previous attempts to scan membrane surfaces have been made using scanning electrochemical microscopy. This technique relies on measuring a current generated from an electrochemical reaction on the surface; consequently, the resolution has been low. In the proposed method, the PI will attempt to measure the potential resulting from a platinum nanoprobe contacting an ionic cluster. Higher sensitivity and higher two- and three-dimensional resolution is anticipated. If the topography of the ionic clusters can be measured, the effects of membrane pretreatment and manufacturing process on cluster formation could be quantified. Fundamental understanding of the behavior of ionic clusters could lead to improvements in fuel-cell membrane assemblies.