Water-mediated ion-ion interactions are enhanced at the water vapor-liquid interface.

ABSTRACT: There is overwhelming evidence that ions are present near the vapor-liquid interface of aqueous salt solutions. Charged groups can also be driven to interfaces by attaching them to hydrophobic moieties. Despite their importance in many self-assembly phenomena, how ion-ion interactions are affected by interfaces is not understood. We use molecular simulations to show that the effective forces between small ions change character dramatically near the water vapor-liquid interface. Specifically, the water-mediated attraction between oppositely charged ions is enhanced relative to that in bulk water. Further, the repulsion between like-charged ions is weaker than that expected from a continuum dielectric description and can even become attractive as the ions are drawn to the vapor side. We show

SUBMITTER: Venkateshwaran V 

PROVIDER: S-EPMC4066534 | biostudies-literature | 2014 Jun

REPOSITORIES: biostudies-literature