Non-Equilibrium View of the Amorphous Solidification of Liquids with Competing Interactions

TL;DR

This paper applies a non-equilibrium theoretical framework to understand how liquids with competing short-range attractions and long-range repulsions undergo dynamical arrest, leading to diverse glass and gel states.

Contribution

It introduces the first use of non-equilibrium self-consistent generalized Langevin equation theory to SALR systems, linking thermodynamic instabilities with kinetic arrest phenomena.

Findings

Thermodynamic instabilities promote phase separation.

Kinetic arrest leads to amorphous solidification.

Diverse glass and gel states emerge from the interplay.

Abstract

The interplay between short-range attractions and long-range repulsions (SALR) characterizes the so called liquids with competing interactions, which are known to exhibit a variety of equilibrium and non-equilibrium phases. The theoretical description of the phenomenology associated to glassy or gel states in these systems has to take into account both, the presence of thermodynamic instabilities (such as those defining the spinodal line and the so called $\lambda$ line) and the limited capability to describe genuine non-equilibrium processes from first principles. Here we report the first application of the non-equilibrium self-consistent generalized Langevin equation theory, to the description of the dynamical arrest processes that occur in SALR systems after being instantaneously quenched into a state point in the regions of thermodynamic instability. The physical scenario predicted by this theory reveals an amazing interplay between the thermodynamically-driven instabilities, favoring equilibrium macro- and micro-phase separation, and the kinetic arrest mechanisms, favoring non-equilibrium amorphous solidification of the liquid into an unexpected variety of glass and gel states.