Dr. D. Truzzolillo

Laboratoire Charles Coulomb (L2C), UMR 5221 CNRS-Universite de Montpellier, France

Dynamic and structural signature of jamming of soft repulsive colloids

Abstract

 

Studying two distinct colloidal systems (PniPam microgels and charged silica particles) we experimentally pointed out the existence of both anomalous dynamic and structural behavior of soft colloids suspensions approaching the jamming transition. Combining macroscopic (rheology) and microscopic (SAXS and time resolved DLS)  investigation, we show that the onset of yield-stress  is followed by : 1) a minimum of the stretching exponent characterizing the decay of the dynamic structure factor; 2) a very weak dependence of the structural relaxation time on particle volume fraction above jamming and 3) a concomitant maximum of the height of the first peak of the static structure factor vs volume fraction. Looking at the fundamental differences both in terms of morphology and particle-particle interactions between the two colloidal systems investigated, we believe that our results are general and might concern a wide class of soft colloids.


Date: 20/1/2016
Time:12:00 (coffee & cookies will be served at 00:00)
Place:FORTH Seminar Room 1