Macroscopic mechanical behavior and microscopic dynamics in network-forming systems

Conf’luence Luca Cipelletti
L2C UMR 5221 Université de Montpellier and CNRS, Montpellier – Institut Universitaire de France

Vendredi 19 novembre à 10 h 30 – Amphithéâtre Nougaro
En live :

Abstract :

I’ll describe recent experiments in our group where we couple rheology measurements to space and time-resolved dynamic light scattering, aiming at understanding the relationship between microscopic dynamics and linear and non-linear viscoelastic properties. I’ll show that the microscopic dynamics is a very sensitive indicator of the ultimate fate of soft solids, able to detect precursors signs of failure well ahead other microscopic or macroscopic quantities [1,2]. I’ll then focus on mucus gels, where an unexpected acceleration of the microscopic dynamics is seen upon applying a very modest shear strain, well within the rheological linear regime [3].

[1]   Aime, S., Ramos, L. & Cipelletti, L. Microscopic dynamics and failure precursors of a gel under mechanical load. PNAS 115, 3587–3592 (2018).

[2]   A. Pommella, L. Cipelletti, L. Ramos, Role of normal stress in the creep dynamics and failure of a biopolymer gel, L., Phys. Rev. Lett. 125, 268006 (2020).

[3] D. Larobina, A. Pommella, A.-M. Philippe, M. Y. Nagazi, L. Cipelletti, Enhanced microscopic dynamics in mucus gels under a mechanical load in the linear regime, to appear in PNAS.

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