Industrializable synthesis of narrow-dispersed carbon dots achieved by microwave-assisted selective carbonization of surfactants and their applications as fluorescent nano-additives

A robust and cost-efficient strategy for the large-scale synthesis of carbon dots (C-dots) allowing structural control was developed by microwave-assisted selective carbonization of surfactants. In this strategy, surfactants serving as carbon sources were transformed into C-dots constructed by a cross-linked core and peripheral fatty chains after the carbonization of the hydrophilic moiety. The pendent fatty chains did not only provide the C-dot good oil-solubility but also promised uniform nanoscale structure by restricting the core growth during the carbonization due to their higher and higher steric hindrance on the surface. As examples, four inexpensive industrial surfactants were selected to synthesize C-dots in kilogram scale, which showed no limitation in further enlargement. The resultant C-dots showed significant fluorescence and were subjected to polymer synthesis and processing as nano-additives for preparing fluorescent polymeric materials, polymer melt viscosity reduction, and mechanical reinforcement. Both the ideal industrializable synthesis and ideal association with polymer synthesis and processing indicate that the C-dots are ready to go from lab to industry. The robust and economic strategy for the large-scale synthesis of narrow-dispersed hydrophobic C-dots and their successful application as fluorescent nano-additives indicate that C-dots are ready to go from lab to industry.