Long-chain surface-modified red-emitting carbon dots as fluorescent additives for 3D printing vat-photopolymerization†

Carbon dots have recently attracted tremendous scientific attention thanks to their enhanced luminescence properties, photostability and low toxicity. In particular, red-emitting carbon dots (RCDs) are assuming increasing importance in biomedical applications, such as bio-imaging and phototherapy. At the same time, the possibility to create functional and complex objects by means of vat-photopolymerization-based three-dimensional (3D) printing techniques is continuously growing. This work describes the synthesis of long-chain surface-modified red emitting carbon dots, L-RCDs by esterification of RCDs, obtained from green reagents with a new solvothermal synthesis, and their employment as fluorescent additives in two formulations of photopolymerizable resins. The printing process proceeded smoothly in all cases, and red-emitting objects with different mechanical properties have been successfully obtained.