PET-RAFT polymerization catalyzed by cadmium selenide quantum dots (QDs): Grafting-from QDs photocatalysts to make polymer nanocomposites

Abstract

We report herein the first example of light-controlled radical reversible addition–fragmentation chain transfer (RAFT) polymerization facilitated by cadmium selenide (CdSe) quantum dots (QDs) as the photocatalyst and the grafting-from CdSe QDs nanoparticles to create polymer-QDs nanocomposites in a one pot photopolymerization. The CdSe QDs undergo a monophase ligand exchange with chain transfer agents (CTAs) via bithiol groups, enabling dispersion of CdSe in polar solvents as well as the grafting of CTAs on the surface of QDs. Photoinduced electron transfer (PET) between QDs and free CTAs facilitates the polymerization of multitude of functional monomers with temporal control, low dispersity (Đ ≈ 1.06), and high chain-end fidelity. More importantly, we leveraged CdSe QDs bound to CTAs to synthesize well-dispersed core–shell organic–inorganic polymer-QDs nanocomposites using a grafting-from polymerization approach.