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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 35: Poster Session II
CPP 35.65: Poster
Wednesday, March 29, 2023, 11:00–13:00, P1
Studying Solid-liquid Contact Charge Separation Dynamics using Mirror Charge — •Pravash Bista1, Hans-Jürgen Butt1, and Stefan A.L Weber1,2 — 1Max-Planck-Institut for Polymer research Mainz — 2Johannes Gutenberg University of Mainz
Charge separation as water drops slide over a hydrophobic solid surface is a well known phenomenon (Slide electrification). Nevertheless, a macroscopic understanding of dynamics in solid-liquid contact charge separation is still incomplete. To address that, we introduce a method based on "mirror charge" detection to locally measure the change in surface charge density (Δ σ). Here, we placed a grounded metal electrode parallel beneath the substrate. As a spontaneously charged drops move over a surface, they attract opposite charge in the metal electrode causing a flow of capacitive current. Analysing this current, we studied Δ σ dynamics with increasing slide length and drop number as multiple deionized water drops slid down the inclined hydrophobic surface (trichloro(1H,1H,2H,2H-perfluorooctyl)silane, PFOTS-functionalized glass). Using the results, we estimated a set of parameters to describe the Δ σ dynamics in slide electrification. Further, we used these parameters in a numerical simulation where we numerically reproduced the experimental results.