Speaker: Professor Abraham D. STROOCK

Institution: Gordon L. Dibble '50 Professor and William C. Hooey Director Robert Frederick Smith School of Chemical and Biomolecular Engineering, Cornell University

Host by: Prof. Hongkai WU

Abstract

On land and in the atmosphere, a dominant form of water is the capillary-condensed liquid within nanometer-scale pores and defects in organic and inorganic solids. In the biosphere, this liquid state defines the availability of water for chemistry and life in soils and controls the transpiration process in plants; in the atmosphere, it plays a critical role in defining the activity of aerosol particles as nuclei for the formation of clouds. The thermodynamic, dynamic and chemical properties of this highly confined liquid water have remained incompletely understood due to the lack of experimental tools for direct interrogation. In this presentation, we will introduce a set of nanofabricated systems and optical measurement techniques developed in our lab to perform quantitative measurements of these elusive properties. We will proceed to provide several illustrative examples of these measurements: 1) exploiting phase-equilibrium with unsaturated vapors and massive capillary stresses, we will show that the dynamics of liquid water (and other common solvents) in few-nanometer-scale confinement agree, quantitatively, with bulk predictions if account is taken for a mono-molecular layer of immobilized liquid. 2) Working under related conditions, we will present an unprecedented measurement of the solubility of molecular oxygen in liquid water at negative pressures and show that the solubility in capillary condensed water rises significantly (> 2x) under common atmospheric conditions. 3) Exploiting a micro-nano-fluidic system, we will present the first direct measurements of the state of liquid in metastable equilibrium with ice at supercooled temperatures (the Gibbs-Thomson effect). We will conclude with a brief discussion of implications for our understanding of environmental phenomena and of perspectives for technological applications.

About the speaker

After completing a bachelor's degree in Physics at Cornell, Abraham Stroock spent two years in France. There he worked in the research division of Electricite de France and completed a master's degree at the University of Paris VI and XI in Solid State Physics. He then returned to the US to pursue a PhD in the Chemistry department at Harvard University with George Whitesides. In the winter of 2003, he joined the School of Chemical and Biomolecular Engineering at Cornell University as an Assistant Professor. He is the recipient of the Henry and Camille Dreyfus New faculty award (2003), the Office of Naval Research's Young Investigator award (2004), the 3M Non-Tenured Faculty Award (2006), the Beckman Foundation Young Investigator Award (2006), MIT Technology Review's TR35 list of top innovators under 35 (2007), and the NSF CAREER Award (2008), Camille Dreyfus Teacher Scholar Award (2009), and the Van Ness Lectureship at Rensselaer Polytechnic Institute (2010).