[SY-M3] Symposium M-3

[SY-M3] Time- and History-dependent Structure and Morphology of van-der-Waals Liquids forming Physical Gels and Porous Glasses

^○Magdaleno Medina-Noyola, Leticia Lopez-Flores, Jose Manuel Olais-Govea, Benigno Zepeda-Lopez (Instituto de Fisica (Laboratorio Nacional de Ingenieria de la Materia Fuera de Equilibrio), Universidad Autonoma de San Luis Potosi, Mexico)

In spite of its relevance, no universal principle seems to exist that explains how Boltzmann’s postulate S = k_B ln W operates for non-equilibrium conditions, predicting, for example, the transformation of liquids into non-equilibrium amorphous solids (glasses, gels, etc.) in terms of molecular interactions. Here, however, we present evidences that the missing fundamental principle to understand non-equilibrium states of matter is provided by Onsager’s description of irreversible processes and thermal fluctuations, adequately combined with Boltzmann’s postulate and extended to genuine non-equilibrium conditions [J. Phys.: Cond. Matter 21: 504103 (2009)]. Formatted as the non-equilibrium self-consistent generalized Langevin equation (NE-SCGLE) theory of irreversible processes in liquids [Phys. Rev. E 82, 061503 (2010)], this approach has been shown to provide a fundamental tool for the understanding of the most essential fingerprints of the transformation of liquids into amorphous solids, such as their aging kinetics or their dependence on the protocol of fabrication [J. Chem Phys. 143, 174505 (2015); Phys. Rev. E 96, 022608 (2017)]. In this work we focus on the NE-SCGLE-predicted scenario of the structural and morphological transformation of van-der-Waals (or "Lennard-Jones--like") simple fluids into hard-sphere glasses at hight densities and temperatures, into physica gels at intermediate densities and low temperatures, into porous glasses at intermediate densities and even lower teperatures, and into cluster-cluster aggregates al very low densities and temperatures. As an illustration, we present the visualization of the non-equilibrium development and arrest of sponge-like structures by arrested spinodal decomposition. The comparison of the theoretical predictions (based on a simple specific model system), with simulation and experimental data measured on similar but more complex materials, suggests the universality of the predicted scenari.