Introduction by guest editors

We herein report the use of carbon dots (CDs) in photoinduced atom transfer radical polymerizations (ATRP) as green metal-free sensitizers. In particular, the production of a polymethacrylate (poly-METAC, METAC = 2-(methacryloyloxy)ethyl]trimethylammonium chloride) by using cheap and easily affordable CDs made from citric acid and diethylenetriamine, under both ultraviolet (UV, λ = 365 nm) and visible light was studied. Different solvent systems have been tested and a CuII complex was used as catalyst. Under the best conditions a polymer in 89% conversion and with a narrow dispersity (1.4) was obtained. The first order kinetics and the “on-off” experiments gave further evidence of the constant concentration of radicals and of the controlled mechanism of the polymerization.