Lattice Gas Model for the Drying-Mediated Self-Assembly of Nanorods

A coarse-grained lattice gas model is developed to study drying-mediated self-assembly of nanorods. Out-of-equilibrium simulations of the model provide insight into the dynamics of solvent evaporation and the formation of ordered arrays of nanorods. Two different initial depositions of the nanorods on the substrate are studied: a random deposition and a prealigned deposition. We show that an initial random alignment of the nanorods in a thin liquid layer typical of drop casting experiments leads to local order only on time scales relevant for experiments. On the other hand, long-range order can be achieved when external forces are used to prealign the nanorods before evaporation. The effects of nanorod coverage, aspect ratio, spatial and orientational diffusion, and evaporation schemes are discussed.