Intermittent dynamics and logarithmic domain growth during the spinodal decomposition of a glass-forming liquid Auteur(s): Testard V., Berthier L., Kob W. (Article) Publié: The Journal Of Chemical Physics, vol. 140 p.164502 (2014) Texte intégral en Openaccess : Ref HAL: hal-00991464_v1 PMID 24784282 Ref Arxiv: 1309.1587 DOI: 10.1063/1.4871624 WoS: 000336047700043 Ref. & Cit.: NASA ADS Exporter : BibTex | endNote 57 Citations Résumé: We use large-scale molecular dynamics simulations of a simple glass-forming system to investigate how its liquid-gas phase separation kinetics depends on temperature. A shallow quench leads to a fully demixed liquid-gas system whereas a deep quench makes the dense phase undergo a glass transition and become an amorphous solid. This glass has a gel-like bicontinuous structure that evolves very slowly with time and becomes fully arrested in the limit where thermal fluctuations become negligible. We show that the phase separation kinetics changes qualitatively with temperature, the microscopic dynamics evolving from a surface tension-driven diffusive motion at high temperature to a strongly intermittent, heterogeneous and thermally activated dynamics at low temperature, with a logarithmically slow growth of the typical domain size. These results shed light on recent experimental observations of various porous materials produced by arrested spinodal decomposition, such as nonequilibrium colloidal gels and bicontinuous polymeric structures, and they elucidate the microscopic mechanisms underlying a specific class of viscoelastic phase separation. Commentaires: 18 pages |