A simple approximation for the distribution of ions between charged plates in the weak coupling regime
- Author(s)
- Andrei Bazarenko, Marcello Sega
- Abstract
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(s)
- Computational and Soft Matter Physics
- External organisation(s)
- Forschungszentrum Jülich
- Journal
- Journal of Molecular Liquids
- Volume
- 271
- Pages
- 301-304
- No. of pages
- 4
- ISSN
- 0167-7322
- DOI
- https://doi.org/10.1016/j.molliq.2018.08.148
- Publication date
- 09-2018
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103029 Statistical physics
- Keywords
- ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials, Condensed Matter Physics, Materials Chemistry, Atomic and Molecular Physics, and Optics, Spectroscopy, Physical and Theoretical Chemistry
- Portal url
- https://ucris.univie.ac.at/portal/en/publications/a-simple-approximation-for-the-distribution-of-ions-between-charged-plates-in-the-weak-coupling-regime(bd6f236e-b6af-4a59-9fba-ef6353ec3b7a).html