Bulk ionic screening lengths from extremely large-scale molecular dynamics simulations
Johannes Zeman1, Svyatoslav Kondrat, Christian Holm
1Institute for Computational Physics, University of Stuttgart, D-70569 Stuttgart, Germany. holm@icp.uni-stuttgart.de.
Chemical Communications (Cambridge, England)
|December 7, 2020
Summary
Large-scale simulations reveal two distinct screening lengths in concentrated electrolytes, but find no evidence of the anomalous "underscreening" phenomenon reported in recent experiments. This suggests non-bulk effects may explain experimental observations.
Area of Science:
- Physical Chemistry
- Computational Nanoscience
- Materials Science
Background:
- Recent experiments show anomalously large screening lengths in confined electrolytes and ionic liquids.
- This 'underscreening' effect was attributed to the bulk properties of dense ionic systems.
Purpose of the Study:
- To investigate bulk ionic screening using large-scale molecular dynamics simulations.
- To determine if bulk properties can explain the observed underscreening phenomenon.
Main Methods:
- Extremely large-scale molecular dynamics simulations.
- Analysis of interionic potentials of mean force with high accuracy (10^-5 kBT).
Main Results:
- Two distinct screening lengths were identified, each following unique scaling relations.
- No evidence of underscreening was found within the simulation's accuracy.
Conclusions:
- Bulk properties alone do not appear to explain the experimental underscreening observations.
- The study suggests that other factors beyond bulk effects are likely responsible for the experimental findings.
