Synthesis of a fluorescent cation surfactant derived from carbon quantum dots

Carbon quantum dots (CQDs) with easier preparation, lower manufacture cost and fluorescent feature caught extensive interests. Herein, a technique of synthesizing a novel cationic surfactant, derived from CQDs via chemical modification, was reported in this work in detail. Firstly, the CQDs were synthesized by aqueous solutions of citric acid and 3-(dimethylamino)-1-propylamine under hydrothermal condition at 180 °C for 60 min. Then the CQDs reacted with excess 1-chlorododecane in alcohol medium via quaterisation for synthesizing the CQDs cationic surfactant. During the processes, the solvent alcohol as well as the excess of 3-(dimethylamino)-1-propylamine and 1-chlorododecane could be isolated efficiently and recycled. The experimental results showed that the CQDs cationic surfactant possessed versatility such as a good performance of reducing the surface tension of water, wonderful antibacterial effect on colibacillus at a lower concentration and a high fluorescent quantum yield.