Evaporation-Driven Coassembly of Hierarchical, Multicomponent Networks.

Self-assembly is an increasingly popular approach to systematically control the formation of complex, multicomponent materials with structural features orders of magnitude larger than the constituent colloidal nanocrystals. Common approaches often involve templating prefabricated patterns to control particle organization- or programming-specific interactions between individual building blocks. While effective, such fabrication methods suffer from major bottlenecks due to the complexity required in mask creation for patterning or surface modification techniques needed to program directed interactions between particles. Here, we propose an alternative strategy that aims to bypass such limitations. First, we design a ligand structure that can bridge two distinct nanocrystal types. Then, by leveraging the solvent's evaporative dynamics to drive particle organization, we direct a cross-linked, multicomponent system of nanocrystals to organize hierarchically into ordered, open-network structures with domain sizes orders of magnitude larger than the constituent building blocks. We employ simulation and theory to rationalize the driving forces governing this evaporation-driven process, showing excellent agreement across theory, simulations, and experiments. These results suggest that evaporation-driven organization can be a powerful approach to designing and fabricating hierarchical, multifunctional materials.