As a result of recent experiments, it is now known that the atoms or molecules in liquids can arrange themselves into layers near the surface. The nanoscale surface region therefore resembles a liquid crystal rather than the liquid itself. The objective of this project is a detailed and systematic study of this phenomenon using synchrotron radiation. The knowledge gained from these studies will help determine how and why liquid surface properties are different from bulk liquid properties. Liquid surfaces play important roles in many familiar processes such as waves, wetting/spreading/coating, evaporation, the formation of droplets and aerosols in clouds and elsewhere, thin film technology, industrial processes, etc. Therefore, these studies may ultimately lead to benefits to society from being able to better understand and control such processes. This project will integrate research and teaching by training graduate students in an interdisciplinary environment, and also by giving them experience in the use of national facilities such as the Advanced Photon Source and the National Synchrotron Light Source. A new undergraduate course called "Physics of Fluid" is being developed, and a "Materials Science Module" about liquids will be produced for use in high schools.
Normal (isotropic) liquids, both metallic and nonmetallic, are now known to form stratified surface regions at sufficiently low temperatures. The objective of this project is a detailed and systematic study of these ordering phenomena. The dependence of observed surface layering in nonmetallic liquids on temperature and on properties of the material such as surface tension will be investigated in detail using synchrotron X-ray scattering. Identification of universal qualitative and quantitative features and trends in the layering behavior of different materials will be sought. These studies may ultimately lead to a better understand of, and more control over, the ubiquitous processes in which liquid surfaces play essential roles. This project will integrate research and teaching by training graduate students in an interdisciplinary environment, and also by giving them experience in the use of synchrotron facilities. A new undergraduate course called "Physics of Fluids" is being developed, and a "Materials Science Module" about liquids will be produced for use in high schools.
