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PICS Colloquium: “Molecular Engineering of Ice Responsive Materials: Decoding Heterogeneous Ice Nucleation”

April 2, 2021 at 2:00 PM - 3:00 PM
Details
Date: April 2, 2021
Time: 2:00 PM - 3:00 PM
Event Category: Colloquium
  • Event Tags:
  • Organizer
    Penn Institute for Computational Science (PICS)
    Phone: 215-573-6037
    Venue
    Zoom – email kathom@seas.upenn.edu

    Abstract: 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.