Modeling Hofmeister Effects

Barbara Hribar-Lee,1,* Vojko Vlachy1 and Ken A. Dill2

1 Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5, 1000 Ljubljana, Slovenia
2 Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94143-2240.
* Corresponding author: E-mail:

A two dimensional model of water, so-called Mercedes-Benz model, was used to study effects of the size of hydrophobic solute on the insertion thermodynamics in electrolyte solutions. The model was examined by the constant pressure Monte Carlo computer simulation. The results were compared with the experimental data for noble gasses and methane in water and electrolyte solution. The influence of different ions at infinite dilution on the free energy of transfer was explored. Qualitative agreement with the experimental results was obtained. The mechanism of Hofmeister effects was proposed.

Keywords: Mercedes-Benz model, hydrophobic hydration, Hofmeister effect, salting-out, Monte Carlo