Heterogeneous Fluorescent Organohydrogel Enables Dynamic Anti-Counterfeiting
Heterogeneous Fluorescent Organohydrogel Enables Dynamic Anti-Counterfeiting
复制标题
DOI：
10.1002/adfm.202108365
复制
发表时间：
2021-09-24
影响因子：
19
通讯作者：
Chen, Tao
中科院分区：
文献类型：
--
作者：
Le, Xiaoxia;Shang, Hui;Chen, Tao
荧光图案响应于外部刺激而显示出独特的颜色变化，这对于它们在防伪方面的应用是相当感兴趣的。但是，目前还缺乏高安全级别的智能荧光图案，呈现加密信息的动态显示。通过两步互穿技术制备了含萘酰亚胺基团（DEAN，黄绿色荧光单体）的聚（N，N-二甲基丙烯酰胺）（PDMA）水凝胶网络和含螺吡喃基团（SPMA，光致变色单体）的聚甲基丙烯酸十八酯（PSMA）有机凝胶网络。由于独特的异质网络，荧光颜色经历了一个连续的变化，从绿色到黄色到红色，通过荧光共振能量转移（FRET）过程随着照射时间的延长。此外，当H+被引入到系统中时，SP单元在UV光下表现出转化为质子化的mercury（MCH+）而不是mercury（MC），这抑制了FRET过程。通过选择性地用H+处理，荧光有机水凝胶可以作为加密秘密信息的有效平台，使它们更难以伪造。
Fluorescent patterns showing the unique color change in response to external stimuli are of considerable interest for their applications in anti-counterfeiting. However, there is still a lack of intelligent fluorescent patterns with high-security levels, presenting a dynamic display of encrypted information. In this study, a fluorescent organohydrogel is fabricated through a two-step interpenetrating technique, leading to the co-existence of naphthalimide moieties (DEAN, green-yellow fluorescent monomer) contained Poly(N,N-dimethylacrylamide) (PDMA) hydrogel network and Polyoctadecyl methacrylate (PSMA) organogel network bearing spiropyran moieties (SPMA, photochromic monomer). Due to the unique heterogeneous networks, the fluorescence color goes through a continuous change from green to yellow to red via the fluorescence resonance energy transfer (FRET) process with the extension of irradiation time. In addition, when H+ is introduced into the system, SP units exhibit transformation into the protonated merocyanine (MCH+) rather than merocyanine (MC) under UV light, which inhibits the FRET process. By selectively being treated with H+, the fluorescent organohydrogel can act as an effective platform for encrypting secret information, making them more difficult to forge.