Three-dimensional (3D) printing utilizing controlled polymerization systems is emerging as a powerful approach to fabricate “living” objects, which can be further modified with various functionalities. Here, we report photoinduced free radical-promoted cationic reversible addition–fragmentation chain transfer (RAFT) polymerization under broad wavelengths from ultraviolet (UV) to near-infrared (NIR) light. A commercially available iron catalyst, cyclopentadienyl iron dicarbonyl dimer (Fe₂(Cp)₂(CO)₄), was used as the photocatalyst, and several diphenyliodonium salts were examined as oxidants. Various poly(vinyl ether)s with controlled molecular weights and a narrow dispersity (1.06–1.32) were prepared through this method. Relatively high chain-end fidelity can be observed and has been demonstrated by successful chain-extension experiments. In addition, benefiting from the penetrating ability of NIR light, 3D objects with different thicknesses were achieved by employing stereolithography-based 3D printing techniques. Furthermore, the postfunctionalization of these 3D printed objects with fluorescent monomers provides a facile method to build 3D objects with complex functionality and potential applications in anticounterfeiting materials.

中文翻译：

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光诱导自由基促进阳离子 RAFT 聚合实现“活”3D 打印

利用受控聚合系统的三维 (3D) 打印正在成为一种强大的制造“活”物体的方法，可以通过各种功能对其进行进一步修改。在这里，我们报告了在从紫外 (UV) 到近红外 (NIR) 光的宽波长下光诱导自由基促进的阳离子可逆加成-断裂链转移 (RAFT) 聚合。市售的铁催化剂，环戊二烯基铁二羰基二聚体（Fe ₂ (Cp) ₂ (CO) ₄) 被用作光催化剂，并研究了几种二苯基碘鎓盐作为氧化剂。通过该方法制备了各种分子量可控、分散度窄（1.06-1.32）的聚（乙烯基醚）。可以观察到相对较高的链端保真度，并已通过成功的扩链实验得到证明。此外，得益于近红外光的穿透能力，采用基于立体光刻技术的 3D 打印技术实现了不同厚度的 3D 物体。此外，这些 3D 打印物体与荧光单体的后功能化提供了一种简便的方法来构建具有复杂功能的 3D 物体和在防伪材料中的潜在应用。