Sustainable Quantum Dot-Vitrimer Composites: A Synergy of Quantum Dots and Dynamic Covalent Bonds.

Functional nanocomposites combining quantum dots (QDs) and polymers have garnered significant attention due to their unique optical properties. However, the presence of toxic heavy metal ions remains a significant challenge for eco-friendly material development. Herein, the design and fabrication of a quantum-dot-in-vitrimer (QD@vitrimer) nanocomposite is introduced, which leverages dynamic covalent bonds, providing chemical extractability of the embedded QDs from crosslinked polymers. Unlike commercially available UV-cured resins, the QD@vitrimer nanocomposite demonstrates uniform QD dispersion with minimal aggregation, as confirmed by synchrotron transmission small-angle X-ray scattering and high-resolution scanning transmission electron microscopy. The composites can be degraded via an alcoholysis process driven by built-in catalysts, enabling rapid breakdown and efficient QD extraction under neutral conditions. 99.9% QD extraction efficiency is achieved while preserving the crystal structure and photoluminescence quantum yield of the QDs, significantly enhancing the reusability of these valuable nanomaterials, as verified by inductively coupled plasma optical emission spectrometry and synchrotron X-ray absorption spectroscopy. Finally, the QD@vitrimer nanocomposite is refabricated using the recycled QDs, establishing a closed-loop system that extends the material's lifecycle. This work highlights the pioneering strategy for developing chemically recyclable, eco-friendly luminescent nanocomposite, offering a new direction for advancing green materials in advanced applications.