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Finding Minimal Energy Paths for Droplets on Superhydrophobic Surfaces: A Phase Field ApproachKellen PetersenDepartment of Mathematics, New York University Monday, July 30, 2012 15:00-16:00, Interest in superhydrophobic surfaces has recently increased due to a number of interesting advances in science and engineering. Here we use a diffuse interface model for droplets on topographically and chemically patterned surfaces in the regime where gravity is negligible. We then examine the transition of droplets between different metastable/stable states by finding the minimal energy paths (MEPs) which correspond to the most probable transition pathways in the configuration space. In the case of a hydrophobic surface with posts of variable height and separation, we determine the MEPs corresponding to the transition between the Cassie-Baxter and Wenzel states. Additionally, we realize critical droplet morphologies along the MEP, associated saddle points of the free-energy potential and corresponding energy barriers. We analyze and compare the MEPs and free-energy barriers for a variety of surface geometries, droplets sizes, and static contact angles ranging from partial wetting to complete wetting. Speaker Bio: Kellen obtained his undergraduate degrees in Mathematics and Physics from the University of Utah and Master's degree in Mathematics from the Courant Institute (NYU). He is currently a doctoral student at the Courant Institute expecting to graduate in the Spring of 2013. He is interested in wetting and spreading, physical applications of diffuse interface theory, and complex fluids.
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