Dynamic Structuring of Water at Mesoscopic Length Scales in the Presence of Moderate High-Voltage Fields

Understanding the behavior of water under moderate but technologically relevant high-voltage electric fields is important for biological systems, water-treatment technologies, and interfacial phenomena. Here, we investigate pure water exposed to non-homogeneous electric fields of approximately 106 V m−1 in a free-hanging horizontal electrohydrodynamic bridge, a regime commonly encountered in electrohydrodynamic devices and biological membranes. Using spatially resolved Raman spectroscopy we identify mesoscopic signatures: sidebands in the OH stretching region. These observations indicate dynamically ordered water domains whose properties differ from bulk water. The results provide new physicochemical insight into electrically stressed water and are consistent with mesoscopic ordering phenomena relevant to applied water systems.