The significant in situ multicolored patterning without changing printing tools nor substrate media still remains challenging, especially toward practical applications for anti-counterfeiting. This research invented a unique universal approach for the laser-induced in situ synthesis of colorful fluorescent patterns (from blue: CIE 0.15, 0.18 to red orange: CIE 0.36, 0.39) through the controlled formation of N, S doped carbon dots (CDs) in solid composite polymer films or hydrogel with a hierarchical and physically unclonable microsurface architecture for anti-counterfeiting. The in situ patterning approach, coupled with multi-layer technique, yielding designable blue, yellow, orange, and red orange color under 365 nm in the same pattern. A 5 cm² colorful pattern can be efficiently finished within 5 min without changing substrate and the line width accuracy can be up to 300 μm. The absolute quantum efficiency of the blue pattern reached as high as 23 %. The fluorescent patterns can be survived at indoor for 24 months. The hydrogen bonding interactions between the CDs precursor and polymer facilitated the generation, uniform dispersion and stabilization of CDs during the laser irradiation. The hypothesis that laser irradiation induced photochemical reactions of CD precursors within a polymer matrix was supported by thermodynamic assessments. The universality of in situ fluorescent patterning strategy was demonstrated by developing fluorescent patterns on both solid polymer films, hydrogel, pharmaceutical packaging and textile

中文翻译：

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通过红外 CO2 激光写入对聚合物涂层中的碳点进行快速原位光化学合成，用于颜色可调荧光图案化


在不更换印刷工具或基材介质的情况下，重要的原位多色图案仍然具有挑战性，尤其是对于防伪的实际应用。这项研究发明了一种独特的通用方法，通过在固体复合聚合物薄膜或水凝胶中控制形成 N、S 掺杂碳点 （CD） 来激光诱导原位合成彩色荧光图案（从蓝色：CIE 0.15、0.18 到红橙色：CIE 0.36、0.39），具有分层和物理不可克隆的微表面结构用于防伪。原位图案化方法与多层技术相结合，在 365 nm 下以相同的图案产生可设计的蓝色、黄色、橙色和红橙色。无需更换基板，即可在 5 分钟内高效完成 5 cm² 的彩色图案，线宽精度可达 300 μm。蓝色图案的绝对量子效率高达 23 %。荧光模式可以在室内存活 24 个月。CDs 前驱体和聚合物之间的氢键相互作用促进了激光照射过程中 CDs 的产生、均匀分散和稳定。激光照射诱导聚合物基体内 CD 前驱体的光化学反应的假设得到了热力学评估的支持。通过在固体聚合物薄膜、水凝胶、药品包装和纺织品上开发荧光图案，证明了原位荧光图案化策略的通用性