Evidence for Spinodal Phase Separation in Two-Dimensional Nanocrystal Self-Assembly

Abstract

The drying of thin nanocrystal solution films creates a varied range of structured aggregate spatial patterns as a function of surface coverage. These images can be understood as predicted kinetic stages in the fluid-fluid spinodal phase separation of a 2D van der Waals particle system. It is suggested that phase separation occurs due to increased van der Waals nanocrystal−nanocrystal interaction in the presence of air, as compared with the shielded interaction in organic solvents.