Engineering Glasses And Gels Using Soft Colloids
July 21-24, 2019
At high concentration, dispersions of deformable particles such as emulsion droplets microgels, micelles and star polymers form entropic and jammed glasses that behave like weak elastic solids at rest but yield and flow at high stresses. In the jammed regime, the packed amorphous microstructure of the suspensions lies at the heart of their generic rheological behavior. Individual particles are trapped in cages and can only move past one another appreciably if the local stress exceeds the strength of the contact interactions.
Chemistry offers a panel of strategies to tune the internal architecture of particles and the contact interactions, which in the general case involve elastic repulsion and attractions of different origins. We will review recent advances that bridge the gap between particle scale properties, local architecture, and macroscopic rheology, thereby opening new routes towards the rational design of glasses and gels using soft colloids. A special attention will be given to stimuli-responsive microgels which can be seen as the archetype of soft colloids. We will demonstrate that weakly crosslinked microgels belong to a new universality class of soft colloids whereas attractive interactions lead to a dual glass-gel paradigm.
Michel Cloitre, "Engineering Glasses And Gels Using Soft Colloids" in "Colloidal, Macromolecular and Biological Gels II", Samiul Amin, Manhattan College, USA Saad Khan, North Carolina State University, USA Srini Raghavan, University of Maryland College Park, USA Eds, ECI Symposium Series, (2019). https://dc.engconfintl.org/cmb_gels_ii/39