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The Three-Phase Contact Potential Difference Modulates the Water Surface Charge
Publikationstyp
Journal Article
Date Issued
2023-05-25
Sprache
English
Author(s)
Artemov, Vasily
Frank, Laura
Doronin, Roman
Stärk, Philipp
Andreev, Anton
Leisner, Thomas
Radenovic, Aleksandra
Kiselev, Alexei
Volume
14
Issue
20
Start Page
4796
End Page
4802
Citation
Journal of Physical Chemistry Letters 14 (20): 4796-4802 (2023)
Publisher DOI
Scopus ID
Publisher
American Chemical Society
The surface charge of an open water surface is crucial for solvation phenomena and interfacial processes in aqueous systems. However, the magnitude of the charge is controversial, and the physical mechanism of charging remains incompletely understood. Here we identify a previously overlooked physical mechanism determining the surface charge of water. Using accurate charge measurements of water microdrops, we demonstrate that the water surface charge originates from the electrostatic effects in the contact line vicinity of three phases, one of which is water. Our experiments, theory, and simulations provide evidence that a junction of two aqueous interfaces (e.g., liquid-solid and liquid-air) develops a pH-dependent contact potential difference Δφ due to the longitudinal charge redistribution between two contacting interfaces. This universal static charging mechanism may have implications for the origin of electrical potentials in biological, nanofluidic, and electrochemical systems and helps to predict and control the surface charge of water in various experimental environments.
DDC Class
620: Engineering