Communication: Kinetic and pairing contributions in the dielectric spectra of electrolyte solutions

Autor(en)

M. Sega, S. S. Kantorovich, C. Holm, A. Arnold

Abstrakt

In the late 1970s, Hubbard and Onsager predicted that adding salt to a polar solution would result in a reduced dielectric permittivity that arises from the unexpected tendency of solvent dipoles to align opposite to the applied field. Here we develop a novel non-equilibrium molecular dynamics simulation approach to determine this decrement accurately. Using a thermodynamic consistent allatom force field we show that for an aqueous solution containing sodium chloride around 4.8 mol/l, this effect accounts for 12% of the total dielectric permittivity. The dielectric decrement can be strikingly different if a less accurate force field for the ions is used. Using the widespread GROMOS parameters, we observe in fact an increment of the dielectric permittivity rather than a decrement, caused by ion pairing and introduced by a too low dispersion force.

Organisation(en)

Institut für Computergestützte Biologische Chemie, Computergestützte Physik und Physik der Weichen Materie

Externe Organisation(en)

Ural Federal University, Universität Stuttgart

Journal

Journal of Chemical Physics

Band

140

Anzahl der Seiten

5

ISSN

0021-9606

DOI

https://doi.org/10.1063/1.4880237

Publikationsdatum

06-2014

Peer-reviewed

Ja

ÖFOS 2012

104017 Physikalische Chemie, 103006 Chemische Physik

Schlagwörter

ASJC Scopus Sachgebiete

Allgemeine Physik und Astronomie, Physical and Theoretical Chemistry

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/1724dc0e-5384-485d-95b6-a503dceee6f9