Encapsulating carbon dots in polymethyl methacrylate nanoparticles toward improved solid-state fluorescence quantum yield

In this paper, we prepare carbon dots (CDs) through hydrothermal method, and then the CDs are encapsulated in polymethyl methacrylate (PMMA) nanoparticles through the suspension polymerization of MMA nanodroplets, obtaining a CD/PMMA nanocomposite with a CD concentration of 0.3 wt%. The CDs of the nanocomposite are confined in the PMMA nanoparticles, so there is no excessive resonance energy transfer or direct π-π interaction among the CDs in different nanoparticles, weakening the aggregation caused quenching compared with conventional CD/PMMA composite fabricated by directly blending the CDs with bulk PMMA. Consequently, the quantum yield (QY) of this CD/PMMA nanocomposite is higher than that of the conventional CD/PMMA composite, and even very close to that of the dilute CD solution. This study may provide a universal method to prepare CD/polymer solid-state fluorescent materials with higher QYs compared with conventional CD/polymer composites prepared through direct blending CDs with bulk polymers.