Assembly by Solvent Evaporation: Equillibrium Clusters and Relaxation Times

We present a theoretical and computational description of equillibrium clusters of alkylthiolated gold nanocrystals assembled by solvent evaporation. We consider N nanocrystals in an octane or nonane liquid droplet. Equillibrium structures consist of Tetrahedron (N=4), Square pyramid (N=5), Octahedron (N=6), Pentagonal bipyrimad (N=7), Biaugmented triangular prism (N=8), Gyroelongated square pyramid (N=9), Sphenocorona (N=10), Icosahedron (N=13). We also characterize the relaxation times of the system and show that they increase linearly with N, thus deviating from the classical Maxwell theory of solvent evaporation. Implications for self-assembly of superlattices will also be discussed.