Gabriele Sosso
(University of Warwick)

The configurational entropy plays a key role in many theories of the glass transition, perhaps most prominently in Adam–Gibbs theory. In this context, the configurational entropy connects the dynamical slowing of supercooled liquids as they approach the glass transition to the number of their accessible configurations. Estimating the configurational entropy via computer simulations is a challenging endeavour, which somewhat surprisingly has not yet been undertaken for mixtures of molecular liquids. In this talk, I will present a tentative framework to do just that, by combining liquid entropy calculations with a potential energy landscape approach and applying it to mixtures containing rigid water and flexible methanol molecules. The resulting configurational entropy is consistent with Adam–Gibbs scaling for the diffusion of both species, although its predictive advantage over an Arrhenius description is modest and depends on composition. I will also discuss the practical limitations of the calculation and how improving this approach could help connect composition, molecular mobility, and glass formation in more complex mixtures, possibly of relevance in the context of pharmaceutical formulations and cryopreservation protocols.
 

Zoom registration link:
https://zoom.us/meeting/register/-MamirqORPu4ukPzObukRA