The Institute of Chemistry, the Hebrew University of Jerusalem , Edmond J. Safra campus, Givat Ram, Jerusalem, 91904, Israel.
Nano Lett. 2017 Jul 12;17(7):4497-4501. doi: 10.1021/acs.nanolett.7b01870. Epub 2017 Jun 15.
Additive manufacturing processes enable fabrication of complex and functional three-dimensional (3D) objects ranging from engine parts to artificial organs. Photopolymerization, which is the most versatile technology enabling such processes through 3D printing, utilizes photoinitiators that break into radicals upon light absorption. We report on a new family of photoinitiators for 3D printing based on hybrid semiconductor-metal nanoparticles. Unlike conventional photoinitiators that are consumed upon irradiation, these particles form radicals through a photocatalytic process. Light absorption by the semiconductor nanorod is followed by charge separation and electron transfer to the metal tip, enabling redox reactions to form radicals in aerobic conditions. In particular, we demonstrate their use in 3D printing in water, where they simultaneously form hydroxyl radicals for the polymerization and consume dissolved oxygen that is a known inhibitor. We also demonstrate their potential for two-photon polymerization due to their giant two-photon absorption cross section.
增材制造工艺能够制造出从发动机零件到人工器官等复杂且功能齐全的三维（3D）物体。光聚合是最通用的技术，可通过 3D 打印实现这些工艺，它使用光引发剂在吸收光后分解成自由基。我们报告了一种基于混合半导体-金属纳米粒子的新型 3D 打印光引发剂。与传统的光引发剂在辐照时被消耗不同，这些粒子通过光催化过程形成自由基。半导体纳米棒吸收光后，发生电荷分离和电子转移到金属尖端，从而在有氧条件下进行氧化还原反应形成自由基。特别是，我们证明了它们在水中的 3D 打印中的用途，其中它们同时形成用于聚合的羟基自由基，并消耗已知抑制剂溶解氧。由于其巨大的双光子吸收截面，我们还证明了它们在双光子聚合中的潜力。
