Speaker: Xin Yong, Assistant Professor of Mechanical Engineering at Binghamton University
Title: Brand New “Coffee Ring”: Interfacial Transport and Assembly
Abstract: Drying droplets of colloidal suspensions typically leave ring-like deposits at the periphery of the droplet footprints, resembling stains of coffee spills. This intriguing and ubiquitous phenomenon, known as the coffee-ring effect, has been investigated extensively in the part two decades due to its wide applications in photonics, diagnostics, and additive manufacturing. Many experimental, theoretical, and computational studies have uncovered complex fluid dynamics and interfacial phenomena in evaporating droplets that underpin the formation of ring patterns. However, the majority of documented efforts to date focused on particles dispersed in the bulk of the droplet. The dynamics of particles confined at the liquid-air interface remain largely unexplored. This presentation will describe recent advances in understanding transport and assembly of colloidal particles on the surface of evaporating sessile droplets and how colloidal interfacial assembly modulates deposition structures, mainly through computer simulations. Perspectives on how this new paradigm of coffee-ring effect may impact future applications in materials processing and manufacturing will be discussed.
Bio: Xin Yong is currently an assistant professor of mechanical engineering and associated faculty member of the Materials Science and Engineering program at Binghamton University. He received his B.S. in physics at Peking University in 2007 and Ph.D. in mechanical engineering from Rensselaer Polytechnic Institute (RPI) in 2012. After graduation, he completed a postdoctoral training in the department of chemical and petroleum engineering at the University of Pittsburgh. His research focuses on computational simulations and mathematical modeling of transport processes and interfacial phenomena in soft matter, including colloids, polymer, and biomolecular systems, which are funded by NSF, NIH, and industries. He is a recipient of the Doctoral New Investigator award from the American Chemical Society Petroleum Research Fund.
MSE Seminar Host: Shan Jiang