Molecular\nAdditives as Competitive Binding Agents\nto Control Supramolecular-Driven Nanoparticle Assembly

Colloidal nanoparticle\nassembly methods can produce intricate superlattice\nstructures and often use knowledge of atomic crystallization behaviors\nto guide their design. While this analogy has enabled multiple routes\nto programming colloidal crystallization thermodynamics, fewer tools\nor strategies exist to manipulate nanoparticle superlattice growth\nkinetics in a controlled manner. Here we investigate how small-molecule\nadditives can be used to modulate the thermodynamics and kinetics\nof supramolecular-chemistry-driven nanoparticle assembly. Specifically,\nwe introduce monovalent binding agents into the superlattice growth\nsolution that compete with the multivalent interparticle bonding interactions\ndriving particle assembly, thereby altering interparticle bond strength\nby reducing the number of bridging complexes formed between particles.\nIn this manner, the assemblies can be steered to avoid kinetic traps\nand crystallize into faceted single crystals under isothermal conditions,\nalleviating the need for precise thermal control that has conventionally\nbeen required to produce large, faceted crystals in prior assembly\nmethods.