May 19, 2008

Eli Sloutskin Receives 2008 Julian Baumert Award

Harvard University physicist Eli Sloutskin is the recipient of this year’s Julian Baumert Ph.D. Thesis Award for his work on liquid surfaces and the nanometer-thin layers that cover them. The prize, now in its second year, is given to a researcher who has recently conducted a thesis project that included measurements at the NSLS. It was established in memory of Julian David Baumert, a young Brookhaven physicist who was working on x-ray studies of soft-matter interfaces at the NSLS before he died in June 2006.

Harvard physicist Eli Sloutskin accepts the NSLS Julian Baumert Ph.D. Thesis Award from NSLS Chair Chi-Chang Kao.

Sloutskin, who actually collaborated with Baumert on a number of studies, received his Ph.D. in physics in 2007 from Bar-Ilan University, Israel.

Most of the measurements for Sloutskin’s thesis, titled “Surface Ordering in van-der-Waals and Coulomb Liquids,” came from NSLS beamline X22B. He spent more than 200 days at the beamline, and the resulting research was published in top-tier journals such as Science, Physical Review Letters, the Journal of the American Chemical Society, and Proceedings of the National Academy of Sciences.

“Eli combines first-rate experimental skills with excellent theoretical abilities, and during his Ph.D. studies, he has become a highly mature and independent researcher, in spite of his young age” said Sloutskin’s advisor and Bar-Ilan University physics professor Moshe Deutsch.

One example of this top-notch work, Deutsch said, is Sloutskin’s contribution to the work on surface freezing, an effect in which the surface of a melt of chain molecules freezes at a temperature higher than the bulk. This is the opposite of what’s normally seen in nature, where surfaces crystallize at temperatures lower than the bulk. Understanding this peculiar effect could be valuable to several applications, including the operation of diesel engines – where surface freezing might cause a reduction in the amount of fuel injection into the engine in cold climates – and in the extraction of oils from porous rocks.

Using x-ray reflectivity, grazing incidence diffraction, and surface tension measurements, Sloutskin found a temperature-driven transition in the frozen monolayer at the surface of a molten mixture of two different-length alkanes. In this transition, for which Sloutskin also developed a thermodynamic theory, the crystalline surface layer transforms from a thin to a thick layer. Other novel results in Sloutskin’s thesis include the first measurement of the surface structure of an ionic liquid, where he found a surface enrichment by anions, and a wetting transition of, and subsequent surface freezing in, alkane monolayers on very dilute water/surfactant solutions.

“Eli’s achievements, even at this early stage of his career, are already extraordinary,” Deutsch said. “He is among the top Ph.D. students I have had the good fortune to interact with during my 35 years as a scientist.”

The Baumert award was presented at the 2008 Joint NSLS and CFN Users’ Meeting on May 20. Sloutskin received a $500 honorarium and travel arrangements to the Users’ Meeting, where he gave a 15-minute presentation on his thesis work.