Thermal-Response of Promesogenic-Ligands Functionalized Nanocrystals

Limited by the mobility of building units, assembled superstructures often lack dynamics, narrowing the potential for applications in smart materials. Here we introduce a novel approach using a specially designed dendritic ligand that exhibits liquid crystal-like behavior at the interface to enable the realization of dynamic superlattices. The ligands act as a thermally triggered lubricant between nanocrystals. It allows the substrate-bounded (dried) nanocrystal solids to transform from poorly ordered aggregates to superlattices with high crystallinity and preferred orientation simultaneously when subjected to thermal activation. With the help from <i>in situ</i> X-ray scattering, the process of the reorientation of the superlattices are revealed and the bottom-to top transition was observed. The superlattice also prefer to expose the most stable facet at the interface to the substrate.