Long-Lived Glassy States in Dense Nearly Hard Sphere Colloids

(Received 26 May 1994, accepted in final form 10 October 1994)

Abstract
By means of Brownian dynamics simulation methods for a Yukawa-potential system and for a hard-sphere system, we investigated systematically the induction time after a rapid compression until crystallization takes place in nearly hard-sphere colloidal systems. Although long-lived disordered states have been experimentally found for an effectively one-component colloidal system, we found that such a state cannot be realized by simulations using a purely one-component system with a spherically-symmetric simple interparticle interaction potential. We found that a crystalline state can exist stably when the size polydispersity is larger than some critical value as is predicted by recent density functional theories. We also found that even a smaller size polydispersity than the critical one can make a disordered state considerably stable, while other factors play minor roles in the stabilization of the disordered states in comparison. We therefore tentatively attribute the considerable stability of the disordered states observed in experiments to the particle size polydispersity.