Some effects of ion model polarizability on the structure and electrostatic properties of aqueous salt solution-vapor interfaces

PHYS 265

G. Lee Warren, gwarren@udel.edu and Sandeep Patel, spatel@mail.chem.udel.edu. Chemistry and Biochemistry, University of Delaware, Newark, DE 19716
Vital insight into myriad interface-dominated processes in atmospheric and biological chemistry is gained through a comprehensive understanding of aqueous solution-vapor interfaces of simple inorganic salt solutions. The rich complexity and ionic character of these interfaces leads to a variety of salt-specific structural and electrostatic perturbations which can dramatically affect the bulk solubility of proteins (Hofmeister effects) and can sensitively modulate the surface reactivity of anions. Using long (>80 ns) molecular dynamics simulations of explicit salt solution-vapor interfaces, we obtain well-converged estimates of the effects of ion polarizability on a variety of interfacial properties including the Gibbs surface excess, surface potentials, surface relaxation effects, interfacial characteristics and depth-dependent distributions of water orientations and permanent and induced multipole moments (including water quadrupole moments).