The Chinese University of Hong Kong, Hong Kong
Lei Xu obtained his PhD in Physics Department of the University of Chicago in 2006, and did his postdoc in School of Engineering and Applied Sciences in Harvard University from 2006 to 2009. He then joined the Physics Department of The Chinese University of Hong Kong in 2009 and he is currently a Professor working in the field of soft condensed matter experiment.
We study the breakup of a liquid thread inside another liquid at different surface tensions. In general, the pinch-off of a liquid thread is governed by the dynamics of fluid flow. However, when the interfacial tension is ultralow (2–3 orders lower than normal liquids), we find that the pinch-off dynamics can be governed by bulk diffusion. By studying the velocity and the profile of the pinch-off, we explain why the diffusion-dominated pinch-off takes over the conventional breakup at ultralow surface tensions.