Barbara Wyslouzil is funded by a Small Grant for Exploratory Research to study the chemical enrichment which takes place on the surface of liquid aerosol droplets. The phenomenon to be studied, i.e., surface enrichment in aerosol droplets of a binary liquid mixture, has been predicted but never directly observed. A supersonic nozzle which can produce monodispersed aerosol droplets has been developed by Wyslouzil, and will be used in a collaborative research efforts involving the use of the Small Angle Neutron Scattering facility in Grenoble, France to perform the studies. Wyslouzil will also be collaborating with researchers at Lawrence Livermore National Laboratories on the project. Surface enrichment has an important effect on heterogeneous chemistry, growth and evaporation kinetics, and nucleation. Multicomponent, nanometer-sized aerosols are produced by nucleation and condensation in many industrial and natural settings. Fine refractory aerosols form in combustion and metallurgical processes while sulfuric acid - water aerosols are produced in stack gases, volcanic plumes, and as byproducts of photochemical reactions in the atmosphere. The surface composition of these particles can strongly affect heterogeneous reactions, growth and evaporation kinetics.