Department of Physics, NCU
Why are flowing soap films stable?
Speaker
Dr. Ildoo Kim
Postdoctoral Research Associate, Brown University
Date 2018.05.07 (Mon)
Time 11:00-12:00
Place S4-208
數學與理論物理中心
Center for Mathematics and Theoretical Physics
Abstract: Soap bubbles and films are abundant and can be seen in everywhere from the household kitchen to the large factory. In science, the flowing soap films are useful tools to simulate two-dimensional flows. These liquid films are very thin (several microns) but mechanically stable so they can last for a long time (several minutes). In this talk, the underlying physical mechanisms that makes those thin films stable will be discussed. The key mechanism is the elasticity that arises from the adsorption of surfactants to the interface. Soap film possesses equilibrium and out-of-equilibrium, depending on the time scale. We introduce experimental measurements of two elasticities, which are rationalized by the equation of state and the Langmuir adsorption model.