title: Halide affinity for the water-air interface in aqueous solutions of mixtures of sodium salts.
abstract: The water-air interface plays a critical role in many physical and chemical processes of the Earth's atmosphere. In particular, heavy halide ions are strongly involved in processes of fundamental importance in determining the prevalence of many atmospheric components through heterogeneous reactions at the water-air interface. In this work, molecular dynamics simulations are used to study the halide enhancements at the water-air interface in the case of mixtures of Cl(-), Br(-), and I(-) ions. The results show a pattern of enhancement directly correlated to the anion polarizability. This effect is explained in terms of the charge distribution across the slab resembling an electrical double layer. As a result, the anions with higher polarizability lower the system's potential energy by enhancing their presence at the interface.
authors.affiliation: Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, USA.
authors.forename: Ivan
authors.initials: I
authors.lastname: Gladich
authors.forename: Paul B
authors.initials: PB
authors.lastname: Shepson
authors.forename: Marcelo A
authors.initials: MA
authors.lastname: Carignano
authors.forename: Igal
authors.initials: I
authors.lastname: Szleifer
mesh_terms: D000388:Air; D006219:Halogens / Q000737:chemistry*; D008958:Models, Molecular; D056004:Molecular Dynamics Simulation; D012492:Salts / Q000737:chemistry; D012964:Sodium / Q000737:chemistry*; D012996:Solutions; D014867:Water / Q000737:chemistry*
chemical_list: D006219:Halogens; D012492:Salts; D012996:Solutions; D014867:Water; D012964:Sodium