Ven. 11/10/2019 14:00 Andromede, Bâtiment 11, Etage 3
GOKHALE Shreyas (Department of Physics, Massachusetts Institute of Technology)
Collective effects in colloidal systems: From glassy dynamics to active noise-driven clustering
Colloidal systems - collections of micrometer-sized particles suspended in a solvent - constitute a versatile and important class of soft materials. On one hand, they serve as optically visible analogues of atoms and molecules, providing valuable information on local structure and dynamics associated with a variety of condensed matter phenomena such as crystal nucleation and glass formation. On the other hand, they serve as mesoscopic building blocks that can be self-assembled into functional materials. In this talk, I will illustrate both of these applications of colloidal systems through specific examples. In the first part, I will demonstrate how information on particle dynamics from experiments on dense colloidal suspensions can be harnessed to critically compare and contrast microscopic predictions of the Random First-Order Transition Theory and Dynamical Facilitation, which are two prominent competing theories of glass formation. In the second part, I will show that purely repulsive colloidal particles undergo dynamic clustering when immersed in an active bath composed of motile bacteria. The clustering dynamics are governed by the interplay between short-ranged effective attraction between colloids mediated by collisions with bacteria and long-ranged hydrodynamic interactions. These experiments open a new route to nonequilibrium self-assembly at the micrometer scale driven by the “active noise” generated by self-propelled particles.
Pour plus d'informations, merci de contacter Truzzolillo D.