Talk by Maxime Bergman on October 5 at 3:00 p.m in Aula 2 Ed. Fermi, Sapienza

in ,

We are pleased to announce a seminar by Dr. Maxime Bergman (University of Fribourg) to be held in Aula 2 (2nd floor of the Fermi building, Department of Physics, Sapienza) on Tuesday, October 5 at 3:00 p.m.

Title Wave-driven particles at a fluid interface: quantum analogs and active dynamics

Abstract

Microgels have been shown to compress in stages: with increasing concentration, interpenetration of the networks occurs first, followed by faceting and finally isotropic compression. Each of these stages has its signature in the resultant yield and elastic moduli, and it is generally observed that a transition takes place from colloidal
dynamics to polymer behavior [1].

We have studied the liquid-to-solid transition of microgel suspensions using conventional macrorheology at 20, 24 and 28C. We capture the plateau value Gp of the storage modulus G'(w) as function of concentration, including overpacked conditions. Our aim is to link the evolution of Gp to the various stages of compression using a free energy minimization model [2] which explicitly considers entropic, brush and core contributions to the sample elasticity.

[1] G. M. Conley, C. Zhang, P. Aebischer, J. L. Harden and F. Scheffold, Nat. Comm., 10(1), 1-8 (2019)

[2] H. S. Kim, F. Scheffold and T. G. Mason, Rheol. Acta, 55(8), 683-697 (2016)