TY - JOUR
T1 - Interfacial, Electroviscous, and Nonlinear Dielectric Effects on Electrokinetics at Highly Charged Surfaces
AU - Rezaei, Majid
AU - Mitterwallner, Bernhard G.
AU - Loche, Philip
AU - Uematsu, Yuki
AU - Netz, Roland R.
AU - Bonthuis, Douwe Jan
N1 - Funding Information:
We thank Alexander Schlaich for discussions. We gratefully acknowledge funding by the Deutsche Forschungsgemeinschaft (DFG) via Grant NE810/11. This project received funding from the European Union’s Horizon 2020 Research and Innovation Programme under Grant Agreement 674979-NANOTRANS and from the Max Planck Water Initiative. M.R. thanks Ahmad Reza Azimian, Ahmad Reza Pishevar, and Isfahan University of Technology for support. Y.U. was supported by JSPS KAKENHI Grant JP20K14430.
Publisher Copyright:
© 2021 The Authors. Published by American Chemical Society.
PY - 2021/5/13
Y1 - 2021/5/13
N2 - The dielectric constant and the viscosity of water at the interface of hydrophilic surfaces differ from their bulk values, and it has been proposed that the deviation is caused by the strong electric field and the high ion concentration in the interfacial layer. We calculate the dependence of the dielectric constant and the viscosity of bulk electrolytes on the electric field and the salt concentration. Incorporating the concentration and field-dependent dielectric constant and viscosity in the extended Poisson-Boltzmann and Stokes equations, we calculate the electro-osmotic mobility. We compare the results to literature experimental data and explicit molecular dynamics simulations of OH-terminated surfaces and show that it is necessary to additionally include the presence of a subnanometer wide interfacial water layer, the properties of which are drastically transformed by the sheer presence of the interface. We conclude that the origin of the anomalous behavior of aqueous interfacial layers cannot be found in electrostriction or electroviscous effects caused by the interfacial electric field and ion concentration. Instead, it is primarily caused by the intrinsic ordering and orientation of the interfacial water layer.
AB - The dielectric constant and the viscosity of water at the interface of hydrophilic surfaces differ from their bulk values, and it has been proposed that the deviation is caused by the strong electric field and the high ion concentration in the interfacial layer. We calculate the dependence of the dielectric constant and the viscosity of bulk electrolytes on the electric field and the salt concentration. Incorporating the concentration and field-dependent dielectric constant and viscosity in the extended Poisson-Boltzmann and Stokes equations, we calculate the electro-osmotic mobility. We compare the results to literature experimental data and explicit molecular dynamics simulations of OH-terminated surfaces and show that it is necessary to additionally include the presence of a subnanometer wide interfacial water layer, the properties of which are drastically transformed by the sheer presence of the interface. We conclude that the origin of the anomalous behavior of aqueous interfacial layers cannot be found in electrostriction or electroviscous effects caused by the interfacial electric field and ion concentration. Instead, it is primarily caused by the intrinsic ordering and orientation of the interfacial water layer.
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U2 - 10.1021/acs.jpcb.0c11280
DO - 10.1021/acs.jpcb.0c11280
M3 - Article
C2 - 33939436
AN - SCOPUS:85106495696
VL - 125
SP - 4767
EP - 4778
JO - Journal of Physical Chemistry B
JF - Journal of Physical Chemistry B
SN - 1520-6106
IS - 18
ER -