PNNL

Abstract

We study the detailed solvation properties of salt sodium iodide at the liquid/vapor interface of methanol that include surface tensions and density profiles as well as transport mechanism of an iodide anion across the methanol interface using molecular dynamics techniques. Polarizable potential models were used to describe interactions among species. The results indicated that the iodide anions were found at the interface more often than sodium cations. The computed potential of mean force showed a relatively small minimum well depth (i.e., -0.60 kcal/mol) locates inside the Gibbs dividing surface. The iodide anion carried some methanol molecules as it crosses the dividing interface. From this study, we can conclude that the population of iodide anions at the liquid water interface is far greater than its population at the liquid methanol interface.