Andrea Giuntoli: A world of information from the picosecond dynamics

Predicting the macroscopic properties of a material from its microscopic features is the Holy Grail of Material Science. It is nevertheless a daunting task, due to the complexity of molecular interactions and emergent phenomena at multiple length and time scales. The hunt is then open for simple microscopic markers of macroscopic behavior, which would shed light on the fundamental physics of these phenomena and provide tools to guide new materials design.

I will show that the mean square displacement of particles at the picosecond time scale, accessible to both simulations and experiments, is a powerful predictor of the dynamics and viscoelastic properties of many glass-forming materials. Theoretical advancements of the last decade provide insight into the nature of the glass transition, linking the picosecond displacement to the dynamical heterogeneity, relaxation time, and elastic modulus of glass-formers. Recent developments of these ideas gave rise to predictive relations for the shear-thinning of polymer melts, state-of-the-art modeling techniques for dynamically informed coarse-grained models, and guidelines for the development of new elastoplastic materials.