New Promesogenic Ligands for Host Medium Microencapsulation by Quantum Dots via Liquid Crystal Phase Transition Templating

The design, synthesis, properties, and performance of a new class of promesogenic calamitic side-tethering organic ligands used to direct quantum dot nanoparticle self-assembly are described. This work was motivated by inadequate modularity, step count, and yield associated with syntheses of existing ligands. Attaching the new ligands to quantum dots and dispersing them in a liquid crystal host affords hollow micrometer-sized capsules via phase transition templating. The capsules resist thermal decomposition up to 350 °C—significantly higher than any previously reported microcapsules assembled from side-tethering calamitic ligand-functionalized nanoparticles. These novel ligands can be used for encapsulation applications where stability under high temperature is required. Evaluation of the capsules by small-angle X-ray scattering shows that interparticle spacing varies from 10 to 13 nm depending on the ligand used and is correlated to aminoalkyl chain length.