POLYMER COMPOSITE MATERIALS BASED ON CARBON DOTS

Carbon dots (C-dots) are promising nanomaterials with unique optical properties, including high photoluminescence, stability and low toxicity compared to traditional phosphors. They can be used as phosphors in light-emitting diodes or active layers in electroluminescent devices and have a long service life. However, their practical application is limited by their tendency to aggregation and concentration quenching in aqueous media. In this paper, we propose a method for stabilizing C-dots by introducing them into polymer matrices - polyvinylpyrrolidone (PVP) and polyvinyl alcohol (PVA), which allows obtaining transparent, mechanically strong and highly efficient luminescent composite materials. C-dots were synthesized by the hydrothermal method from o-phenylenediamine, which provided a high quantum yield (25%) and luminescence in the blue region of the visible spectrum. It was found that the optimal concentration of C-dots in water is 0.02% by weight, but their introduction into polymer matrices made it possible to significantly increase the content of nanoparticles without losing their luminescent properties. The highest luminescence intensity was observed at a concentration of 1.6% by weight of C-dots in both polymer matrices. Using fluorescence microscopy, the uniform distribution of carbon dots in the polymers was confirmed, and based on spectrophotometric analysis, it was shown that the composite films have high transparency in the entire visible range. At the same time, the films demonstrated good photostability: after 6 hours of UV irradiation, the intensity decreased by 27% for PVA-based composites and 30% for PVP-based composites. The obtained results demonstrate that the obtained polymer composite materials based on C-dots have promising characteristics for use as light-transforming coatings and components of various optoelectronic display and information transmission devices, including LEDs, organic displays, light converters, etc.