Photoinduced oxygen-catalyzed RAFT polymerization using heterogeneous bionic enzymes

Abstract

Exploiting aerobic polymerization approaches is the feasible strategy to fundamentally address the phenomenon of oxygen blocking polymerization. A photo-bionic enzyme-reversible addition-fragmentation chain transfer (RAFT) polymerization system (COF/H2O/O2) was successfully constructed,...

Recognition of “Oxygen-/Water-Fueled” PET-RAFT Protocol Matched to Covalent Organic Frameworks

“…To further visualize the intrinsic association of the COF-dominant “oxygen-/water-fueled” PET-RAFT protocol, we performed a controlled analysis of key active species upon each other. The UV–vis spectra of benzoquinone (BQ) (Figures a and S17, S18) recorded a gradual decrease of the characteristic absorption peak with increasing light exposure time, corroborating the suitable reduction potential of the COFs . The comparison shows that with the addition of TEA, the items showed a faster decrease in frequency.…”

“…The UV−vis spectra of benzoquinone (BQ) (Figures 6a and S17, S18) recorded a gradual decrease of the characteristic absorption peak with increasing light exposure time, corroborating the suitable reduction potential of the COFs. 30 The comparison shows that with the addition of TEA, the items showed a faster decrease in frequency. TEA acts as an electron sacrificial agent mainly to trap holes and reduce the recombination efficiency between charge and holes, allowing more photogenerated electrons to come into contact with oxygen.…”

“…•− /H 2 O system suggests a robust and feasible approach to meet the above challenge. 30 However, the relationship between Hence, the O 2 •− /H 2 O system of the "oxygen-/water-fueled" PET-RAFT protocol was investigated to recognize the constraints of the O 2…”

“…Therefore, it remains a formidable challenge to be in a completely open environment, especially in the aqueous phase. The discovery of a COF-based mimetic enzyme-catalyzed O 2 •– /H 2 O system suggests a robust and feasible approach to meet the above challenge . However, the relationship between the mechanism of the O 2 •– /H 2 O system and the structure of COF is not yet clear.…”

Photocontrolled RAFT polymerization: past, present, and future

“…Very recently, Hou, Xiao, Zhao, and coworkers reported that 1,3,6,8-tetrakis(4-formylphenyl)pyrene (TFPPy)-azine based covalent organic frameworks (COFs) generated initiating hydroxyl radicals from water and atmospheric air under white light irradiation (15 mW cm À2 ). 172 Photoinduced production of the superoxide radical anion followed by reaction with water generated hydroxyl radicals. Thus, in a completely open vial, the polymerization rate increased with an increase in the volumetric ratio of water to dioxane, whereas polymerization did not proceed in the absence of water.…”