Broader impacts:

1. X-ray scattering shows thata liquid film becomes more solid-like as it gets thinnerPulak Dutta, Northwestern University, DMR 0705137 It is now known that liquids are layered (and thus not really liquid) at solid-liquid interfaces, and that some liquids are also layered at their surfaces. What happens when such a liquid is in the form of a very thin film, so that the surface and interface layers overlap? We have studied tetrakis(2-ethyl-hexoxy)silane, a classical non-liquid-crystalline liquid. Using synchrotron X-rays, we found that in thinner films the two layered regions are not merely superimposed. Rather, the entire thin film ‘solidifies’ nonlinearly, i.e. rapidly becomes predominantly layered, when the surface and interface regions meet. Physical Review E (Rapid Comm.) 77, 030601 (2008)

2. X-ray scattering shows thata liquid film becomes more solid-like as it gets thinnerPulak Dutta, Northwestern University, DMR 0705137 Broader impacts: When the arrangement of molecules in any material changes, its properties change also. The properties of liquids in the form of thin films are relevant to a wide variety of real-world systems and processes such as lubrication, coatings, painting, etc. Therefore, understanding how molecules arrange in thin liquid films helps to explain the behavior of liquids, and will ultimately lead to ways to make liquids with designed properties. This work was performed through an international collaboration with scientists at the Pohang Accelerator Laboratory, Pohang, Korea. Although the PI is in a Physics department, this research area is at the interface of physics, chemistry and materials science. Students and postdocs gain experience in a wide variety of areas, including training in the use of national synchrotron facilities, and graduate with broad interests and abilities. Two postdocs (Bandyopadhyay, Evmenenko) and one graduate student (Shively) are being partially supported by the current NSF grant. Of graduate students participating in prior NSF grants in the same area, Jan Kmetko and Andrew Richter are now Assistant Professors at Kenyon College and Valparaiso University respectively, and are helping to train new generations of interdisciplinary scientists.