Investigation of Streaming Potential in Electrical Double Layers (2023)

Undergraduate: Halona Dantes

Faculty Advisor: Yue Wu
Department: Physics and Astronomy

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An electrical double layer forms when a solid is immersed in a liquid. This happens due to the contact of two conducting phases. EDLs have been studied extensively due to their various applications. One phenomenon that occurs in EDLs that has garnered interest over the years is called streaming potential. The streaming potential is a phenomenon that occurs when a fluid flows against a solid-liquid interface. This project aimed to use Electrical Impedance Spectroscopy (EIS) to investigate the streaming potential in EDLs and its dependence on salinity and the type of ions in the electrolyte. In addition to this, we also aimed to gain a better understanding of the effects of flow on the impedance of the system. We demonstrated that the magnitude of streaming potential decreases with increasing salinity and varies for different types of ions. In addition to this, we demonstrate the effect of flow on the impedance of the system at lower frequencies as well as the repeatability of this effect using impedance spectroscopy and single-frequency impedance measurements respectively. These results help us gain a better understanding of the surface chemistry of EDLs and how the flow of the electrolyte affects it.

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