香豆素修饰的碳量子点光稳定剂的制备与性能

利用柠檬酸为碳源，通过水热反应制备碳量子点，再采用EDC/NHS酰胺反应催化体系，将7-氨基-4-甲基香豆素(AMC)修饰到碳量子点表面，合成出一种香豆素修饰的碳量子点光稳定剂 (AMC-CQDs)，研究了其光学性能和在纸张表面的应用性能，并且运用1931-CIE色度坐标，初步探究了纸张返黄过程的色度变化规律。结果表明： 合成的AMC-CQDs粒径均匀(4.13nm),具有良好的水溶性和紫外吸收性能，基本实现紫外区的全覆盖吸收,且其最大荧光发射波长为431nm，荧光量子产率达到38.7%，适用于高得率浆纸张增白，对纸张的初始白度可以提高4.71 ISO%；色度坐标显示该碳量子点光稳定剂对于色度坐标位于y＝1.553x－0.184附近的纸张具有良好的光物理增白效果。

Preparation and Properties of Coumarin Modified Carbon Point as Light Stabilizer

The carbon dots were successfully prepared by hydrothermal reaction using citric acid as the carbon source firstly. And then the 7 - amino - 4 - methyl coumarin (AMC) was used to modify the carbon quantum dots in the EDC / NHS amide reaction system to a coumarin-modified carbon light stabilizer (AMC-CQDs). The optical properties and the application properties on the surface of the paper were studied, and the law of change on chromaticity of the paper was analyzed by the 1931-CIE chromaticity coordinates. The results revealed that the synthesized AMC-CQDs had uniform particle size (4.13nm), good water solubility and UV absorption which could realize the full coverage absorption in UV-light area. The maximum fluorescence emission wavelength of AMC-CQDs was 431nm, the fluorescence quantum yield was 38.7% and initial whiteness of the paper could be increased by 4.71 ISO%, which indicated that the compound was suitable for high yield pulp paper whitening. In addition, the results of chromaticity coordinates showed that the carbon light stabilizer had good performance on the physical whitening effect for the paper with chomaticity coordinates near the line y = 1.553x-0.184.