Dr. Domenico Truzzolillo

University of Montpellier, France

Off-equilibrium surface tension in colloidal suspensions



Surface tension between immiscible fluids is a well-understood and well-characterized phenomenon. By contrast, much less is known about the
 effective, off-equilibrium surface tension that arises when a
(transient) interface is created between miscible fluids. I present a thorough experimental investigation of the Saffman-Taylor instability arising when a simple fluid (the solvent of a colloidal or polymer
suspension) is pushed through a miscible, more viscous one (the colloidal or polymer suspension itself). I'll show that the resulting interface pattern can be accounted for by the non-linear rheological properties of the suspension and an effective surface tension. Comparing
 hard particle and polymer suspensions, I'll show how the effective surface tension is affected by the internal structure of the suspended objects.

Date: 28/4/2015
Time:15:00 (coffee & cookies will be served at 14:45)
Place:FORTH Seminar Romm 1