AVS 53rd International Symposium
    Surface Science Tuesday Sessions
       Session SS2-TuM

Paper SS2-TuM11
Ion Depth Profiles at the Liquid - Vapor Interface of Electrolytes in Mixtures of Water and Alcohol

Tuesday, November 14, 2006, 11:20 am, Room 2004

Session: Water-Surface Interactions
Presenter: M.J. Krisch, University of California at Irvine
Authors: M.J. Krisch, University of California at Irvine
M.A. Brown, University of California at Irvine
R. D'Auria, University of California at Irvine
K.M. Callahan, University of California at Irvine
D.J. Tobias, University of California at Irvine
J.C. Hemminger, University of California at Irvine
M. Ammann, Paul Scherrer Institute
H. Bluhm, Lawrence Berkeley National Laboratory
Correspondent: Click to Email
We find that organic compounds modify the interfacial profile of electrolytes in aqueous solutions. Our experiments probe atomic composition at the liquid surface with ambient pressure x-ray photoelectron spectroscopy at the Advanced Light Source. Photoelectron kinetic energies are varied to produce a depth profile of the liquid - vapor interface. Surface enhancement of iodide anions, an effect observed in aqueous potassium iodide solution, disappears in the presence of a surface active alcohol such as 1-butanol. Results are compared to molecular dynamics simulations of the same system. Insight into ion behavior at mixed liquid surfaces is crucial for understanding the chemistry of atmospheric aerosols, which frequently contain ternary mixtures of water, electrolytes, and organics.