Seminar: Sapna Sarupria, Clemson University

“Molecular Ballet of Water on Surfaces: Implications in Heterogeneous Ice Nucleation”

The presence of particles such as dust and pollen affect cloud microphysics significantly through their effect on the state of water. These particles can hinder or accelerate the liquid-to-solid transition of water, and also affect the ice polymorph formed in the clouds. This indirectly cloud reflectivity, cloud lifetime, and precipitation rates. While a predominant phenomenon, the understanding of the surface factors that affect ice nucleation is minimal. In our research, we use molecular simulations to illuminate the pathways through which surface properties influence ice nucleation. Experiments cannot probe the length and time scales relevant to nucleation. While molecular simulations, in principle, can probe the length and time scales of nucleation, in practice nucleation is challenging to sample. Nucleation is often associated with large free energy barriers and thus, is difficult to sample in straightforward simulations. Advanced sampling techniques and other creative approaches are needed. In this talk, I will discuss the insights we have obtained on heterogeneous ice nucleation through studies of three surfaces – silver iodide, kaolinite and mica. I will also highlight the synergistic combination of experiments and simulations in understanding heterogeneous ice nucleation. I will introduce a recently developed method in our group facilitate computational studies of heterogeneous nucleation. I will conclude by providing a perspective on the broader implications of our studies on interfacial phenomena and surface design.

Dr. Sapna Sarupria is an associate professor in Chemical and Biomolecular Engineering at Clemson University. She received her Masters’ from Texas A & M University and her Ph.D. from Rensselaer Polytechnic Institute. She was a postdoctoral researcher in Princeton University. Her research focuses on using molecular simulations to tease out the underlying phenomena governing material behavior. The group is involved in a broad range of projects – ice and hydrate nucleation, development of simulation methods to study rare events, modeling of water purification membranes, and modeling biomolecular assemblies.  She received the NSF CAREER award, ACS COMP Outstanding Junior Faculty Award and Clemson’s Board of Trustees Award of Excellence. She is an active member of Women in Chemical Engineering (WIC) and Computational and Molecular Science and Engineering Forum (CoMSEF) in AIChE.