Dean for Research
Department of Chemical and Biological Engineering
Abstract: The phase behavior of supercooled water: A computational perspective
Water plays a central role in the physical and chemical processes that sustain life as we know it. Its ubiquity and importance notwithstanding, there remain major open questions concerning 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. The existence of a phase transition between two liquid forms of water, terminating at a critical point under deeply supercooled conditions, has been proposed as a thermodynamically consistent way of interpreting experimental observations. After discussing the experimental evidence, I will provide a computational perspective on water’s liquid-liquid transition and on metastable criticality. Computer simulation, powered by advanced sampling algorithms, has played an important role in defining the frontiers of knowledge on supercooled water’s still incompletely understood phase behavior.
Biographical Summary of Pablo Debenedetti:
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, whose faculty he joined in 1985. He received his undergraduate and graduate degrees in Chemical Engineering at the University of Buenos Aires (1978) and at the Massachusetts Institute of Technology (MSc 1981, PhD 1984), respectively. 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. He is the author of one book, Metastable Liquids, and more than 280 scientific articles. His accomplishments include proving the existence of a metastable liquid-liquid transition in a molecular model of water, performing the first direct calculation of homogenous ice nucleation rates in a realistic model of water, and uncovering the relationships between liquid dynamics and exploration of the energy landscape, and between structural order and the anomalies of liquid water. Debenedetti’s honors include the NSF’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), Institute Lecture (2013) and Alpha Chi Sigma (2019) awards from the AIChE; the J. M. Prausnitz Award in Applied Chemical Thermodynamics (2001); the Hildebrand Award in the Theoretical and Experimental Chemistry of Liquids from the ACS (2008); and the Guggenheim Medal from the Institution of Chemical Engineers (2017). He received 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 AIChE. He is a member of the National Academy of Engineering, the American Academy of Arts and Sciences, and the National Academy of Sciences, and a fellow of AAAS, AIChE and APS.