ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Novel A-π-D-π-A structure two-photon polymerization initiators based on phenothiazine and carbazole derivatives

Shanggeng Li, Jiaming Hu, Shuai Zhang, Cheng Feng, Longfei Zhang, Cheng Wang, Zhibing He, and Lin Zhang

Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang, China

E-mail: zhangshuai_scu@126.com

Received: 25 February 2021  Accepted: 21 May 2021

Abstract:

Two-photon polymerization additive manufacturing has great demand for new and efficient two-photon initiators. Acetylene bridged A-π-D-π-A initiator molecules based on phenothiazine and carbazole were designed and synthesized via Sonogashira coupling reaction utilizing benzophenone and fluorenone as electron-donating groups. The ultraviolet-visible absorption spectra, fluorescence emission spectra, two-photon absorption cross section, two-photon fluorescence properties, as well as their photoinitiation properties as initiators, were studied. The results showed that different electron donors and acceptors directly affect the photophysical properties of molecules, and their effects are interrelated. Among them, under the action of femtosecond laser, the two-photon absorption cross section of the molecule with phenothiazine as the donor and benzophenone as the acceptor can reach 327 GM at 780 nm. Two-photon polymerization experiments have also proved that it can indeed initiate trimethylolpropane triacrylate photopolymerization for micro-/nano-manufacturing. The scanning rate reached 2000 μm s⁻¹ at a laser power of 30 mW during the polymerization process, and the complete and clear three-dimensional structures were obtained. The highest resolution of the complete three-dimensional structure was about 280 nm.

Keywords: The additive manufacturing; Two-photon absorption; Photoinitiator; A-π-D-π-A structure

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-021-01713-9

Chemical Papers 75 (10) 5249–5256 (2021)