A simple approximation for the distribution of ions between charged plates in the weak coupling regime

Autor(en)

Andrei Bazarenko, Marcello Sega

Abstrakt

The solution of the Poisson–Boltzmann equation for counterions confined between two charged plates is known analytically up to a constant, namely, the ion density in the middle of the channel. This quantity is relevant also because it gives access, through the contact theorem, to the osmotic pressure of the system. Here we compare the values of the ion density obtained by numerical and simulation approaches, and report a useful analytic approximation for the weak coupling regime in the absence of added salt, which predicts the value of the ion density in the worst case within 5%. The inclusion of higher order terms in a Laurent expansion can further improve the accuracy, at the expense of simplicity.

Organisation(en)

Computergestützte Physik und Physik der Weichen Materie

Externe Organisation(en)

Forschungszentrum Jülich

Journal

Journal of Molecular Liquids

Band

271

Seiten

301-304

Anzahl der Seiten

4

ISSN

0167-7322

DOI

https://doi.org/10.1016/j.molliq.2018.08.148

Publikationsdatum

09-2018

Peer-reviewed

Ja

ÖFOS 2012

103029 Statistische Physik

Schlagwörter

ASJC Scopus Sachgebiete

Electronic, Optical and Magnetic Materials, Condensed Matter Physics, Materials Chemistry, Atomic and Molecular Physics, and Optics, Spectroscopy, Physical and Theoretical Chemistry

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/bd6f236e-b6af-4a59-9fba-ef6353ec3b7a