Vitrification is a spontaneous non-equilibrium transition driven by osmotic pressure

Abstract Persistent dynamics in colloidal glasses suggest the existence of a non-equilibrium driving force for structural relaxation during glassy aging. But implicit assumption literature that form within metastable state bypasses search vitrification and aging its connection with state. The natural relation osmotic pressure to number-density gradients motivates us investigate as this force. We use dynamic simulation quench polydisperse hard-sphere liquid into putative glass region while monitoring pressure. Following quenches various depths volume fraction ϕ (where RCP ≈ 0.678 7% polydispersity), overshoots value, then decreases age toward pressure, redistribution coordination number interparticle voids smooths heterogeneity age. For 0.56 ⩽ 0.58, accessible post-quench redistributes age, allowing relax strong supercooled easily reach At higher fractions, 0.59 < 0.64, encounters barrier is subsequently overcome by system ⩾ overshoot small compared high pressure; stops particles acquire contacts get stuck, freezing far from Overall, drives rearrangements responsible both age-relaxation. energy, structure identifies transition, 0.63 g 0.64. leverage energy density put forth mechanistic view occurs via individual particle motion driven spontaneous minimization process off back