Self-assembly of Dispersed Gold Nanorods and Shape Complementary Mechanism*

Nanoparticle self-assembly promises scalable fabrication of composite materials with unique properties, but the device-size, dynamics process and symmetry control of assembly structures remain challenges. By adjusting the interactive forces and assembly conditions, we realize centimeter-scale self-assembly monolayer of the octagonal gold nanorods. The self-assembly dynamics are investigated by successive optical imagings in the critical stage of a droplet drying containing the dispersed gold nanorods. Shape complementarity is the primary way to control the symmetry of nanoparticle assemblies. Using it, tetragonal superlattice, breaking through the only hexagonal symmetry of the superlattice is realized. Multiscale modeling reveals that the governing forces arise from hierarchical molecular and colloidal interactions. These assembly strategies might be instructive for designing assembly of various nanoparticles and realizing diverse assembly structures with pre-engineered properties.