Zhao Zhengdong, Shen Yuan, Liu Yang, Wang Jiaqi, Ma Mingjian, Pan Jiangbo, Wang Di, Wang Chengyu, Li Jian
Key Laboratory of Bio-based Material Science & Technology, Ministry of Education, Northeast Forestry University, Harbin 150040, China; College of Material Science and Engineering, Northeast Forestry University, Harbin 150040, China.
J Colloid Interface Sci. 2024 Oct 15;672:142-151. doi: 10.1016/j.jcis.2024.05.227. Epub 2024 May 31.
The remarkable optical properties of carbon dots, particularly their tunable room-temperature phosphorescence, have garnered significant interest. However, challenges such as aggregation propensity and complex phosphorescence control via energy level manipulation during synthesis persist. Addressing these issues, we present a facile gel platform for tunable afterglow materials. This involves chemically cross-linking biomass-derived silicon-doped carbon dots with carboxymethylcellulose and incorporating non-precious metal salts (BaCl, CaCl, MgCl, ZnCl, ZnBr, ZnSO) to enhance phosphorescence. Metal salts boost intersystem crossing via spin-orbit coupling, elevating triplet state transitions and activating phosphorescence. Chemical bonding and salt-induced coordination/electrostatic interactions establish confinement effects, suppressing non-radiative transitions. Diverse salt-gel interactions yield gels with tunable phosphorescence lifetimes (9.48 ms to 32.13-492.39 ms), corresponding to afterglow durations ranging from 3.20 to 11.86 s. With its broad tunability and high recognition, this gel material exhibits promising potential for dynamic multilevel anti-counterfeiting applications.
碳点卓越的光学性质，尤其是其可调节的室温磷光，已引起了广泛关注。然而，诸如聚集倾向以及在合成过程中通过能级操纵进行复杂磷光控制等挑战依然存在。为解决这些问题，我们提出了一种用于可调余辉材料的简易凝胶平台。这包括将生物质衍生的硅掺杂碳点与羧甲基纤维素进行化学交联，并加入非贵金属盐（氯化钡、氯化钙、氯化镁、氯化锌、溴化锌、硫酸锌）以增强磷光。金属盐通过自旋轨道耦合促进系间窜越，提高三重态跃迁并激活磷光。化学键合以及盐诱导的配位/静电相互作用产生限制效应，抑制非辐射跃迁。多样的盐 - 凝胶相互作用产生了具有可调磷光寿命（9.48毫秒至32.13 - 492.39毫秒）的凝胶，对应余辉持续时间为3.20至11.86秒。这种凝胶材料具有广泛的可调性和高识别性，在动态多级防伪应用中展现出了广阔的潜力。
