S. Lisa Biswal, Professor Chemical and Biomolecular Engineering (CHBE), Rice University
"Driving Phase Transitions with “Big Atoms” Using Time-Varying Magnetic Fields"
Suspensions of colloids driven out-of-equilibrium demonstrate interesting collective behavior such as organized and directed clustering and swarming. These systems require continuous energy input, yet some of the dynamics of these driven systems resemble the equilibrium phase behavior of molecular fluids, such as crystallization, condensation, and phase separation. Consequently, there has been significant interest in exploring the applicability of thermodynamic concepts, such as pressure and surface tension, to describe nonequilibrium phenomena. I will describe the application of time-varying magnetic fields to induce new dynamical phases. Specifically, we will show how rotating magnetic fields can drive superparamagnetic particles to form steady-state vapor-liquid coexistence that can be analyzed with Kelvin’s equation to determine an "effective vapor pressure" for this active colloidal system. These results illustrate the convergence of statistical physics of simple liquids to nonequilibrium systems.
Sibani Lisa Biswal is the William M. McCardell Professor and Associate Chair in the Department of Chemical and Biomolecular Engineering and Associate Dean for Faculty Development in the George R. Brown School of Engineering at Rice University in Houston, Texas. She has a B.S in chemical engineering from Caltech (1999) and a Ph.D. in chemical engineering from Stanford University (2004). She is the recipient of an ONR Young Investigator Award (2008) and a National Science Foundation CAREER award (2009). She has received the George R. Brown Award for Superior Teaching (2015), the Rice University Alumni Professional Progress Award (2017), and the South Texas Section American Institute of Chemical Engineers Best Applied Paper Award (2018). She was selected as a 2020 Fellow in Drexel University’s Executive Leadership in Academic Technology, Engineering, and Science (ELATES) program. She leads the Soft Matter Engineering Laboratory, where she aims to connect a fundamental understanding of the interfacial forces and transport governing soft matter systems to identify new insights and ideas towards engineering new solutions for a variety of critical technological problems.