利用水热反应, 以柠檬酸为碳源制备碳量子点, 再以2,2,6,6-四甲基哌啶胺为修饰剂, 使碳量子点表面的含氧基团与2,2,6,6-四甲基哌啶胺反应, 实现了碳量子点的功能化。实验结果表明, 修饰后的碳量子点紫外吸收和蓝色荧光发射特性明显优于未修饰的碳量子点。修饰后的碳量子点平均粒径为3.16 nm, 荧光量子产率为21.2%, 水溶性好, 颜色浅, 可作为高得率浆纸张的光稳定剂使用, 并能提高纸张初始白度3ISO%~4ISO%。随着自由基捕获剂基团的引入, 碳量子点能有效捕获纸张因光照而产生的活性自由基, 提高了纸张的耐光性。

Novel carbon dots were successfully synthesized by hydrothermal reaction with citric acid as carbon source, and 4-amino-2,2,6,6-tetramethylpiperidine was used to react with the oxygen-containing groups on carbon dots surface. This method would optimize the properties of carbon dots. The modified carbon dots are better than the unmodified carbon dots on the characteristics of ultraviolet absorption and blue fluorescence-emission. The modified carbon dots exist in average particle size of 3.16 nm, and have high fluorescence quantum yield of 21.2% besides good water solubility and light color. The results show that the novel carbon dots can be used as light stabilizer in papermaking with high yield pulp and improved initial brightness of paper by 3ISO%-4ISO%. With the introducing of the radical scavenger groups, the novel carbon dots can effectively improve the light resistance of paper by capturing free radicals formed under lights.