Crystallization in molecular and colloidal systems by means of computer simulations
Eduardo Sanz, Universidad Complutense de Madrid
Crystallization is often used in separation and purification industrial processes. Most drugs, for instance, are stored and delivered in a crystalline form. Moreover, climate change is strongly influenced by the crystallization of water in tropospheric clouds. It is therefore important to deeply understand the kinetics of this phase transition, and computer simulations is a very suitable tool for this purpose. The reason is that crystallization starts by a nucleation step that consists in the emergence of a small embryo of the crystal phase in the bulk of the parent fluid phase. In molecular systems, such embryo is rather small (contains of the order of 10^2-10^3 molecules) and short-lived (lasts for ~10^-9 seconds) and it can not therefore be directly visualized experimentally. In this talk I will discuss several numerical studies of crystallization. First, I will discuss a case study in which several crystal phases (polymorphs) compete to nucleate in a metastable fluid of oppositely charged colloids. Then, I will present a computational study of homogeneous ice nucleation at low supercoolings. Finally, I will present a study of the mechanism by which a colloidal glass becomes crystalline.