Peng Fang, Chen Yian, Liu Hongchen, Chen Pan, Peng Feng, Qi Haisong
State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou, 510641, China.
College of Textiles, Zhongyuan University of Technology, Zhengzhou, 450007, China.
Adv Mater. 2023 Nov;35(46):e2304032. doi: 10.1002/adma.202304032. Epub 2023 Oct 15.
Smart-response materials with ultralong room-temperature phosphorescence (RTP) are highly desirable, but they have rarely been described, especially those originating from sustainable polymers. Herein, a variety of cellulose derivatives with 1,4-dihydropyridine (DHP) rings are synthesized through the Hantzsch reaction, giving impressive RTP with a long lifetime of up to 1251 ms. Specifically, the introduction of acetoacetyl groups and DHP rings promotes the spin-orbit coupling and intersystem crossing process; and multiple interactions between cellulose induce clustering and inhibit the nonradiative transitions, boosting long-live RTP. Furthermore, the resulting transparent and flexible cellulose films also exhibit excitation-dependent and color-tunable afterglows by introducing different extended aromatic groups. More interestingly, the RTP performance of these films is sensitive to water and can be repeated in response to wet/dry stimuli. Inspired by these advantages, the RTP cellulose demonstrates advanced applications in information encryption and anti-counterfeiting. This work not only enriches the photophysical properties of cellulose but also provides a versatile platform for the development of sustainable afterglows.
具有超长室温磷光（RTP）的智能响应材料备受青睐，但相关报道却很少，尤其是源自可持续聚合物的此类材料。在此，通过汉茨希反应合成了多种带有1,4 - 二氢吡啶（DHP）环的纤维素衍生物，其呈现出令人印象深刻的RTP，寿命长达1251毫秒。具体而言，乙酰乙酰基和DHP环的引入促进了自旋 - 轨道耦合和系间窜越过程；纤维素之间的多重相互作用导致聚集并抑制非辐射跃迁，增强了长寿命RTP。此外，通过引入不同的扩展芳香基团，所得的透明且柔性的纤维素薄膜还表现出激发依赖性和颜色可调的余辉。更有趣的是，这些薄膜的RTP性能对水敏感，并且可以响应湿/干刺激而重复。受这些优点的启发，RTP纤维素在信息加密和防伪方面展现出了先进的应用。这项工作不仅丰富了纤维素的光物理性质，还为可持续余辉的发展提供了一个通用平台。
