Abstract

Using computer simulations we study nucleation in a colloidal supension of hard rods. We study the kinetic pathways for the isotropic-to-nematic transition in a fluid of long hard rods, and find spinodal decomposition as well as nucleation and growth depending on the supersaturation [1]. In supersaturated isotropic fluid states of short hard rods, we observe nucleation of multilayered crystalline clusters. At sufficiently high supersaturations, we find that the nucleation is hampered by glassy dynamics. For intermediat rods, we find that the formation of the (stable) smectic phase out of a supersaturated isotropic state is strongly suppressed by an isotropic-nematic spinodal instability that causes huge spinodal-like orientation fluctuations with nematic clusters diverging in size [2]. In suspensions of colloidal platelets, we find that the cubatic phase is metastable, and that perpendicularly oriented particle stacks in the isotropic fluid phase inhibits the formation of the columnar phase [3].

[1] A. Cuetos and M. Dijkstra, Physical Review Letters 98, 095701 (2007). [2] R. Ni, S. Belli, R. van Roij, and M. Dijkstra, Physical Review Letters 105, 088302 (2010). [3] M. Marechal, A. Patti, M. Dennison, and M. Dijkstra, Physical Review Letters 108, 206101 (2012).