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Pablo Debenedetti

Pablo G. Debenedetti

Class of 1950 Professor in Engineering and Applied Science
Professor of Chemical and Biological Engineering
Dean for Research

Ingeniero Quimico, Buenos Aires University, 1978
M.S., Massachusetts Institute of Technology, 1981
Ph.D., Massachusetts Institute of Technology, 1985

Room: A419 Engineering Quad
Phone: 609-258-5480
Email: pdebene@princeton.edu

Personal Webpage: http://pablonet.princeton.edu/pgd/
Group Webpage: Debenedetti Research Group

Honors and Awards

  • National Academy of Sciences, 2012
  • American Association for the Advancement of Science, Fellow, 2011
  • William H. Walker Award, American Institute of Chemical Engineers, 2008
  • President's Award for Distinguished Teaching, Princeton University, 2008
  • Distinguished Teacher Award, School of Engineering and Applied Science, Princeton University, 2008
  • American Academy of Arts and Sciences, 2008
  • Joel Henry Hildebrand Award in the Theoretical and Experimental Chemistry of Liquids, American Chemical Society, 2008
  • John M. Prausnitz Award in Applied Chemical Thermodynamics, 2001
  • National Academy of Engineering, 2000
  • Professional Progress Award, American Institute of Chemical Engineers, 1997
  • Best Professional/Scholarly Book in Chemistry, Metastable Liquids, Association of American Publishers, 1996
  • Guggenheim Fellow, John Simon Guggenheim Memorial Foundation, 1991
  • Teacher-Scholar Award, Camille and Henry Dreyfus Foundation, 1989
  • Presidential Young Investigator, National Science Foundation, 1987

Publications

Research Areas

Research Interests

My research program investigates the relationship between molecular architecture and the structural, thermodynamic and kinetic properties of condensed matter systems of interest in modern chemical and biological engineering. We employ computational and theoretical methods rooted in statistical mechanics to study problems such as the effects of co-solutes, pressure and temperature on protein stability; the origin of biological homochirality; the structure, dynamics and phase behavior of water in nano-scale confinement; dynamics in supercooled liquids; the thermodynamics of supercooled water; drying and hydration of complex and biological substrates; the thermodynamics, formation mechanisms and formation kinetics of clathrate hydrates; desalintion via clathrate hydrates; and the properties of proteins and other biomolecules under low-moisture conditions and in glassy matrices.

Molecular modeling for sustainable energy technology. Many of the challenges involved in the successful implementation of sustainable energy technologies involve developing new materials or understanding the behavior of systems and materials at severe operating conditions. Modern molecular-based computational methods play an important role in addressing such challenges. Examples of topics currently under investigation in our group include modeling of hydrate melting and formation as a possible approach to carbon sequestration; computational modeling of phase behavior of water, carbon dioxide and salt mixtures for carbon capture and storage and geothermal energy production; computational investigation of water transport in nafion membranes for fuel cells; desalination with gas hydrates for improved fresh water production and greater energy efficiency; molecular modeling of heterogeneous ice nucleation for improved weather and climate models; and molecular modeling of liquid metals as plasma-facing materials for fusion energy systems.

Water and aqueous solutions. The peculiar properties of water include expansion upon cooling, expansion upon freezing, increased fluidity upon compression, anomalously large heat capacity and dielectric constant, and unusually high melting and boiling temperatures. In spite of water’s central role as a matrix for life, as a key determinant of global climate, and as a participant in countless industrial processes, our understanding of its physical properties and that of aqueous solutions is very incomplete. We apply computational and theoretical methods to study problems such as the structure, phase behavior and dynamics of water in nano-scale confinement, the phase behavior of supercooled water, the stabilization of biologically significant structures of proteins in solution and in the glassy state, hydrophobic hydration, and capillary evaporation.

Supercooled liquids and glasses. Glasses are disordered materials that lack the periodicity of crystals but behave mechanically like solids. The glassy state is crucial in the processing of foods and the commercial stabilization of labile biochemicals. The most common way of making a glass is by cooling a viscous liquid fast enough to avoid crystallization. Although this route to the vitreous state – supercooling – has been known for millenia, the molecular processes by which liquids acquire amorphous rigidity upon cooling are not fully understood. We use a combination of molecular simulation and statistical mechanical theory to study fundamental questions on supercooled liquids and the glass transition. Examples include the development of quantitative measures of disorder in computer-generated glasses, glass phenomena in thin films, and the thermodynamics of ideal glasses.

Biopreservation. The commercialization of many valuable biochemicals, such as therapeutic proteins or vaccines, requires the design of formulations that are stable during shipping and long-term storage. Concentrated solutions of carbohydrates in water are widely used in the pharmaceutical industry, generally in vitreous form, for the storage, protection, and formulation of labile biochemicals. The molecular mechanisms by means of which vitreous matrices confer stability to proteins and other biochemicals are poorly understood. We use molecular simulation to study the structure, thermodynamics, and mechanical properties of biomolecules in water-soluble glasses.

Origins of biological homochirality. Chiral asymmetry choices exhibited by molecules that are present in living organisms constitute a scientifically challenging set of observations. Such geometric preferences favoring one enantiomer over its mirror image are obvious in the observed structures of amino acids, sugars, and the biopolymers that they form. These facts automatically generate fundamental questions about how those chiral asymmetries arose spontaneously in the terrestrial biosphere. We formulate thermodynamic and kinetic models of chiral amplification that provide molecular-level insight into possible scenarios for the emergence of chiral imbalance in a prebiotic and presumably racemic world. The models incorporate diverse physical phenomena, such as solid-fluid phase behavior, autocatalysis, inhibition, and crystal attrition.
 


Figure 1. A cascade of anomalies: phase diagram showing loci of structural (blue), transport (red) and thermodynamic (green) anomalies in liquid water, calculated by molecular simulation (Errington and Debenedetti, Nature, 410, 259, 2001).

Figure 2. Snapshot of a molecular simulation of the protein ubiquitin in a mixture of water (red, v-shaped) and the carbohydrate trehalose (blue, red and white sticks). Carbohydrates are used in the pharmaceutical industry to preserve labile biochemicals for long-term storage in low-water-content formulations. Picture courtesy of Harold Hatch.