9500827 Law Ions in solution frequently form electrical double layers at surfaces which modify the surface phenomena of wetting and adsorption. These surface effects are important in many physical, chemical, and biological processes such as lubrication, catalysis, and fluid flow through biological membranes and porous media. This project will use the techniques of elllipsometry and neutron reflectometry to study wetting and adsorption in critical ionic mixtures. These mixtures are known to exhibit either mean field or Ising behavior in the bulk depending upon the dielectric properties of the solvent. This bulk behavior is still not understood from a theoretical point of view. The liquid/liquid and liquid/substrate surface properties of such mixtures have never been studied before and this project should enhance our understanding of the complex interaction between bulk and surface ionic processes %%% Ions in solution frequently adsorb at surfaces and modify the physical characteristics of the surface. This effect can be important in many physical, chemical, and biological membrane processes such as lubrication catalysis and fluid flow through biological membranes and porous media. The adsorption of ions is determined by the underlying properties of the bulk liquid solution. In this project, the surface properties of critical ionic mixtures will be studied, using light reflection and neutron reflection techniques, near the critical temperature where the bulk properties of these solutions vary rapidly with temperature. This proposal will enhance our understanding of the complex interplay between bulk and surface ionic processes. ***
