A novel surfactant synthesized by amidation of carbon nano dots with n-dodecylamine via an entirely green approach

The dense surface functional groups of carbon dots (CDs) provided several reactive sites for chemical modifications that might extend applications of CDs. Herein, we tried to modify nitrogen-doped CDs chemically which obtained by pyrolysis of citric acid and β-alanine with n-dodecylamine in aqueous medium for manufacturing cationic CDs surfactant (represented with NCDs-C12). The dilute solution of NCDs-C12 performed outstandingly in declining the surface tension of water from 72.0 to 32.0 mN m −1 , which was comparable to several new types of cationic surfactants. NCDs-C12 solution (in water medium) was apt to foam, which was by far better than that of some typical surfactants at the same concentration. Additionally, NCDs-C12 was positive charged and behaved perfectly in inhibiting the growth of E. coli or S. aureus . None of any organic solvent was used during the whole procedure. We herein provided a novel route of manufacturing a surfactant with renewable substances.