Substituted Thioxanthone-Based Photoinitiators for Efficient Two-Photon Direct Laser Writing Polymerization with Two-Color Resolution
Substituted Thioxanthone-Based Photoinitiators for Efficient Two-Photon Direct Laser Writing Polymerization with Two-Color Resolution
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DOI：
10.1021/acsapm.0c01291
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发表时间：
2021-02-22
影响因子：
5
通讯作者：
Boudouris, Bryan W.
中科院分区：
文献类型：
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作者：
Chi, Teng;Somers, Paul;Boudouris, Bryan W.
近年来，通过直接激光写入（DLW）光聚合进行的纳米光刻印刷引起了越来越多的关注，因为这种印刷的速度有所提高，而已实现的特征尺寸已大大减小到纳米级范围。具体而言，异丙基噻吨酮 (ITX) 已被用作 DLW 聚合过程中常见的光引发剂之一，因为它具有高效的光引发能力，并且能够通过应用第二波长的光来抑制其引发性能。然而，如果要实施先进的高通量纳米制造技术，学术界和工业界都需要基于这种成功原型构建的改进的光引发材料。在此，通过计算设计并随后合成了具有定制光学和电荷转移特性的下一代噻吨酮基光引发剂。特别是，相对于 ITX 核心，具有专门调节的电子供体和电子受体质量的分支与初始噻吨酮底物偶联。在充分表征其分子和光学特性后，很明显这些引发剂在光聚合引发方面相对于 ITX 具有明显的进步。因此，提出了一种冠军光引发剂化学物质来证明增强的双光子聚合 DLW，从而表现出超分辨率特性。通过这种方式，我们引入了一种清晰的方法，可以系统地设计未来的光引发剂，以增强双光子聚合 DLW 纳米打印工艺。
Nanolithographic printing by direct laser writing (DLW) photopolymerization has attracted increased attention in recent years, as the speed of this printing has increased, while the feature sizes that have been realized have decreased well into the nanoscale regime. Specifically, isopropyl thioxanthone (ITX) has been utilized as one of the common photoinitiators in DLW polymerization processes because of its high-efficiency photoinitiating abilities and its ability to have its initiation properties inhibited through the application of a second wavelength of light. However, improved photoinitiating materials that are built from this successful archetype are required, by both academic and industrial circles, if advanced high-throughput nanomanufacturing techniques are to be implemented. Here, next-generation thioxanthone-based photoinitiators with tailored optical and charge transfer properties were computationally designed and subsequently synthesized. Particularly, branches with specifically modulated electron donor and electron acceptor qualities, relative to the ITX core, were coupled to the initial thioxanthone substrate. After having their molecular and optical properties characterized in full, it was evident that these initiators possessed a clear advancement in terms of photopolymerization initiation relative to ITX. As such, a champion photoinitiator chemistry was brought forward to demonstrate enhanced two-photon polymerization DLW such that superresolution properties were exhibited. In this way, we introduce a clear means by which to systematically design future photoinitiators for enhanced two-photon polymerization DLW nanoprinting processes.