Currently, there are only a few industrial and academic works focused on photopolymerization conducted under natural light. To address this challenge, six new dyes are synthesized as photosensitizers and combined with additives (an amine and an iodonium salt) to create three-component photoinitiation systems. These systems can efficiently initiate both the free radical polymerization (FRP) of an acrylate monomer and the cationic polymerization (CP) of an epoxy monomer. Remarkably, the FRP process, facilitated by these systems under natural sunlight, required only a low loading of dyes (0.1 wt% relative to the monomer), and the conversion obtained with dye-B1 as the photosensitizer can reach 90% within 5 minutes. It highlights the viability of natural sunlight as an efficient light source for polymerization processes. More interestingly, dye-B1 can effectively initiate metal-free CP of an epoxy monomer. The chemical mechanism underlying photopolymerization is comprehensively investigated through a combination of theoretical calculations, photolysis experiments, fluorescence quenching experiments, cyclic voltammetry (CV), and electron spin resonance spin trapping (ESR-ST) experiments. Leveraging the exceptional photoinitiation ability of dye-B1, the corresponding three-component photoinitiating system is applied to 3D printing, achieving high-precision 3D patterns via direct laser writing (DLW).

中文翻译：

---

用于光聚合的阳光驱动光引发系统及其在激光直写中的应用


目前，关注自然光下光聚合反应的工业界和学术界的著作还很少。为了应对这一挑战，合成了六种新染料作为光敏剂，并与添加剂（胺和碘鎓盐）结合以创建三组分光引发系统。这些体系可以有效引发丙烯酸酯单体的自由基聚合（FRP）和环氧单体的阳离子聚合（CP）。值得注意的是，这些系统在自然阳光下促进的FRP工艺仅需要较低的染料用量（相对于单体的0.1 wt%），并且以染料-B1作为光敏剂获得的转化率可以在5分钟内达到90%。它强调了自然光作为聚合过程的有效光源的可行性。更有趣的是，染料-B1 可以有效引发环氧单体的无金属 CP。通过理论计算、光解实验、荧光猝灭实验、循环伏安法（CV）和电子自旋共振自旋捕获（ESR-ST）实验相结合，全面研究了光聚合的化学机理。利用染料-B1优异的光引发能力，将相应的三组分光引发系统应用于3D打印，通过激光直写（DLW）实现高精度3D图案。