Pablo Debenedetti of Princeton University joins us as our 14th Annual Mah Lecturer

Title:Cold WaterAbstract:Water affects every aspect of our lives, from agriculture to climate, and from health to geopolitics. It is a key participant in the physical and chemical processes that sustain life as we know it. Its ubiquity and importance notwithstanding, there remain major open questions about water's physical properties, which are anomalous by comparison to those of most other liquids. Examples include the fact that the liquid, if sufficiently cold, expands when cooled and becomes less viscous when compressed. Water's oddities become more pronounced at low temperatures, especially in the supercooled regime, where the liquid is metastable with respect to crystallization. After introducing some of supercooled water's remarkable properties and their practical implications, I will review some the hypotheses that have been proposed to explain experimental observations. Computer simulations have played an important role in research on supercooled water, in large part because they are not subject to the limitations that make experimental probing of deeply metastable states so challenging. I will illustrate the advantages and limitations of computational investigations of supercooled water, focusing on the intriguing possibility of the existence of a liquid-liquid phase transition.

Bio:Pablo Debenedetti is the Class of 1950 Professor in Engineering and Applied Science, Professor of Chemical and Biological Engineering, and Dean for Research at Princeton University. He received his undergraduate education at the University of Buenos Aires, and his graduate education at the Massachusetts Institute of Technology, where he obtained MS (1981) and PhD (1985) degrees in Chemical Engineering. Since 1985 he has been a faculty member at Princeton University. Prior to becoming Dean for Research, he served as Chair of the Chemical Engineering department (1996-2004), and Vice Dean of the School of Engineering and Applied Science (2008-2013).

His research interests include the thermodynamics and statistical mechanics of liquids and glasses; water and aqueous solutions; protein thermodynamics; nucleation; metastability; and the origin of biological homochirality. Research in Debenedetti's group has helped define the current state of basic knowledge on the properties of metastable liquids and glasses, and brought this vast field to the mainstream of chemical engineering thermodynamics. He is the author of one book, Metastable Liquids, and more than 260 scientific articles. Debenedetti's professional honors include the National Science Foundation's Presidential Young Investigator Award (1987), the Camille and Henry Dreyfus Teacher-Scholar Award (1989), a Guggenheim Memorial Foundation Fellowship (1991), the Professional Progress (1997), Walker (2008) and Institute Lecture (2013) Awards from the American Institute of Chemical Engineers, the John M. Prausnitz Award in Applied Chemical Thermodynamics (2001), the Joel Henry Hildebrand Award in the Theoretical and Experimental Chemistry of Liquids from the American Chemical Society (2008), and the Guggenheim Medal from the Institution of Chemical Engineers (2017). He received the Distinguished Teacher Award from Princeton's School of Engineering (2008), and the President's Award for Distinguished Teaching (2008), Princeton's highest distinction for teaching. In 2008 Debenedetti was named one of 100 Chemical Engineers of the Modern Era by the American Institute of Chemical Engineers. He is a member of the National Academy of Engineering, the American Academy of Arts and Sciences, and the National Academy of Sciences, and is a fellow of the American Association for the Advancement of Science, the American Institute of Chemical Engineers and the American Physical Society.