Dynamic Superlattice from Nanocrystal-Liquid Crystal Hybrid Materials

The growth of superlattices (SLs) made from self-assembled nanocrystals (NCs) is a powerful method for creating new materials and gaining insight into fundamental molecular dynamics. Previous explorations of NCSL syntheses have mostly compared them to crystallization. However, NCSL synthesis has not broadly shown cooling crystallization from saturated solutions as a reversible crystallization–dissolution process. We demonstrate the reversible growth of NCSLs by dispersing NCs in liquid crystal (LC) “smart solvents,” and harnessing the transitions between the isotropic and nematic phases of the LCs. The growth mode and morphology can be tuned. The superlattice from this nanocrystal-liquid crystal hybrid system is very dynamic and with temperature response of drammatic lattice expansion and phase transitions. The resulting materials can be considered as colloidal interstitial solid solutions.