Glassy States in Asymmetric Mixtures of Soft and Hard Colloids

Domenico Truzzolillo (1, 2) , Daniela Marzi (3) , John Marakis (2) , Barbara Capone (3) , Manuel Camargo (4) , Abdul Munam (5) , Firmin Moingeon (5) , Mario Gauthier (5) , Christos Likos (3) , Dimitris Vlassopoulos (2)

1 L2C - Laboratoire Charles Coulomb
2 FORTH-IESL - Institute of Electronic Structure and Laser
3 Faculty of Physics [Vienna]
4 Centro de Investigaciones en Ciencias Básicas y Aplicadas
5 University of Waterloo [Waterloo]

By employing rheological experiments, mode coupling theory, and computer simulations based on realistic coarse-grained models, we investigate the effects of small, hard colloids on the glassy states formed by large, soft colloids. Multiarm star polymers mimic hard and soft colloids by appropriately varying the number and size of their arms. The addition of hard colloids leads, depending on their concentration, to either melting of the soft glass or the emergence of two distinct glassy states.We explain our findings by depletion of the colloids adjacent to the stars, which leads to an arrested phase separation when the repulsive glass line meets the demixing binodal. The parameter-free agreement between experiment, theory, and simulations suggests the generic nature of our results and opens the route for designing soft-hard colloidal composites with tunable rheology.

Domaines: Matière Molle [cond-mat.soft]

Domenico Truzzolillo, Daniela Marzi, John Marakis, Barbara Capone, Manuel Camargo, et al.. Glassy States in Asymmetric Mixtures of Soft and Hard Colloids. Physical Review Letters, 2013, 111 (20), pp.208301. ⟨10.1103/PhysRevLett.111.208301⟩. ⟨hal-00909433⟩