Water in an electric field does not dance alone: The relation between equilibrium structure, time dependent viscosity and molecular motions

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Details zur Publikation

Autorinnen und Autoren: Baer A, Milicevic Z, Smith DM, Smith AS
Zeitschrift: Journal of Molecular Liquids
Jahr der Veröffentlichung: 2019
Band: 282
Seitenbereich: 303-315
ISSN: 0167-7322


Abstract

Dynamic structuring of water is a key player in a large class of processes underlying biochemical and technological developments today, the latter often involving electric fields. However, the anisotropic coupling between the water structure and the field has not been understood on a molecular level so far. Here we perform extensive molecular dynamics simulations to explore the influence of an externally imposed electric field on liquid water under ambient conditions. Using self-developed analysis tools and rigorous statistical analysis, we unambiguously show that water hydration shells break into subcompartments, which were hitherto not observed due to radial averaging. The shape of subcompartments is sensitive to the field magnitude and affects excitations of the hydrogen bond network including the femtosecond stretching and the sub-picosecond restructuring of hydrogen bonds. Furthermore, by analysing the reorientational dynamics of water molecules, we ascertain the existence of cooperative excitations of small water clusters. Enabled by the interplay between hydrogen bonding, and the coupling of water dipoles to the field, these coordinated motions, occurring on the picosecond time scale, are associated with fluctuations between torque-free states of water dipoles. We show that unlike the coupling between translation and reorientation of water molecules, which takes place on even longer time scales, these coordinated motions are the key for understanding the emergent anisotropy of diffusion and viscosity of water. Particular effort is invested to provide an analysis that allows for future experimental validation. (C) 2019 Published by Elsevier B.V.


FAU-Autorinnen und Autoren / FAU-Herausgeberinnen und Herausgeber

Baer, Andreas
Professur für Theoretische Physik
Milicevic, Zoran
Professur für Theoretische Physik
Smith, Ana-Suncana Prof. Dr.
Professur für Theoretische Physik


Einrichtungen weiterer Autorinnen und Autoren

Ruđer Bošković Institute


Zitierweisen

APA:
Baer, A., Milicevic, Z., Smith, D.M., & Smith, A.-S. (2019). Water in an electric field does not dance alone: The relation between equilibrium structure, time dependent viscosity and molecular motions. Journal of Molecular Liquids, 282, 303-315. https://dx.doi.org/10.1016/j.molliq.2019.02.055

MLA:
Baer, Andreas, et al. "Water in an electric field does not dance alone: The relation between equilibrium structure, time dependent viscosity and molecular motions." Journal of Molecular Liquids 282 (2019): 303-315.

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Zuletzt aktualisiert 2019-23-05 um 16:53