Possible Approaches to the Synthesis of Nanocomposites from a Liquid-Crystalline Polymer and CdSe/ZnS Quantum Dots

Liquid-crystalline polymer poly[4-(omega-acryloyloxyhexyloxy)]benzoic acid is synthesized by reversible addition-fragmentation chain transfer polymerization. The ligand exchange reaction of core-shell CdSe/ZnS quantum dots with the gradient composition of constituent elements stabilized by oleic acid (combined with trioctylphosphine) affords 4-(omega-acryloyloxyhexyloxy)benzoic acid-based ligands which are bound through the interaction of carboxyl groups the surface of quantum dots via ionic bonding. The RAFT polymerization of 4-(omega-acryloyloxyhexyloxy)benzoic acid in solution in a mixture with initial quantum dots gives rise to a polymer in which a part of benzoic acid fragments is bound with quantum dots while another part retains the ability to form cyclic dimers. The polymerization product becomes insoluble in organic solvents which most probably indicates that the process of polymerization is accompanied by crosslinking. The direct mixing of quantum dots with poly[4-(omega-acryloyloxyhexyloxy)]benzoic acid in solution causes the partial replacement of quantum dots with macromolecule units while maintaining the liquid-crystalline state of the system in general at the content of quantum dots in the composite up to 50 wt %.