Applied Mathematics Seminar

Title: What happens when water is cooled quickly below freezing

Abstract: Material properties can be predicted through integrals of partition functions in the phase space. By speeding up such integrations through efficient force fields developed with adaptive force matching, the properties of liquid water that is supercooled below freezing is studied. Such properties is difficult to determine experimentally since measurements have to be performed on a timescale shorter than spontaneous formation of ice.  Our simulations provide evidence for the existence of two forms of meta-stable liquid water in the supercooled regime. Precise determination of density, viscosity, and the surface tension of supercooled water through computation allows better interpretation of experimental measurements in this challenging temperature range. A new equation for the temperature dependent surface tension of water is proposed that conforms better to experimental measurements. The new simulation guided interpretation of experiments provides direct support for the existence of more than one form of liquid water in the supercooled regime.

Bio: Dr. Feng Wang received his Ph. D. in Chemistry at University of Pittsburgh working on quantum description of dipole bound electrons. He performed postdoctoral work at University Utah with Prof. Gregory  A. Voth developing methods for concentrated acid simulations. Since his independent career, he focused on methodology for force field development. He is currently the Charles & Clydene Scharlau Professor in Chemistry at the University of Arkansas.