水溶性碳量子点的制备及防伪应用

Preparation and anti-counterfeiting of water-soluble carbon quantum dots

摘要:

以壳聚糖为原料，采用水热法一步制备水溶性的荧光碳量子点（CQDs），考察反应条件（壳聚糖质量浓度、温度和时间）对CQDs产物表面官能团和产率的影响，采用TEM、FTIR、XRD、UV-Vis和PL等技术对其形貌、结构和性能进行了表征，并探究其在防伪领域的应用。结果表明，当壳聚糖质量浓度为10 g/L，温度为180 ℃，时间为12 h时，制得的CQDs结构完整且产率较高；微观表现为球状纳米颗粒，直径约为36.2 nm，表面伴有羟基和氨基官能团；制得的CQDs在293和330 nm处均有吸收峰，表现为蓝色荧光，荧光量子产率约为39.8%。将其配制成墨水后，结合喷墨印刷，在自然光和紫外光下可有效实现加密信息的“显”和“隐”，具有较好的防伪效果。

Abstract:

Fluorescent carbon quantum dots (CQDs) were prepared from chitosan by one-step hydrothermal method. The effects of reaction conditions such as mass concentration of chitosan, temperature and time on surface functional group and yield were investigated. The morphology, structure and properties of samples were characterized by TEM, FTIR, XRD, UV-Vis and PL spectra. The application in the field of anti-counterfeiting was explored. The results showed that the prepared CQDs had complete structure and high yield under the conditions of mass concentration of chitosan of 10 g/L, temperature of 180 ℃, and time of 12 h. The spherical CQDs nanoparticles had a diameter of about 36.2 nm, accompanied by hydroxyl and amino functional groups on the surface. In addition, CQDs exhibited strong absorption peaks at 293 and 330 nm, which show a blue fluorescence. The fluorescence quantum yield was about 39.8%. After they were made into ink for ink-jet printing, the encrypted pattern could be "visible" and "hidden" effectively under natural light and UV light, indicating the ink prepared from CQDs has excellent anti-counterfeiting effect.