Aggregation-Induced Emission Luminogen Catalyzed Photocontrolled Reversible Addition–Fragmentation Chain Transfer Polymerization in an Aqueous Environment
Zhiying Li, Qianjin Lian, Youwei Xu, Yichuan Zhang, Pengfei Zhang, Jin Geng
Abstract
A robust aggregation-induced emission luminogen photocatalyst, 5,6-bis(4′-(diphenylamino)-[1,1′-biphenyl]-4-yl)pyrazine-2,3-dicarbonitrile (DCDPP-2TPA), for photoinduced electron transfer-reversible addition–fragmentation chain transfer (PET-RAFT) polymerization was investigated. A variety of well-defined polymers with narrow polydispersities (Đ < 1.20) were prepared using the donor–acceptor (D–A) type aggregation-induced emission luminogen as a photocatalyst (as low as 5 ppm with respect to monomers) under visible light at ambient temperature. The use of ppm level of metal- or organo-photocatalysts for PET-RAFT polymerization has been investigated before, but mainly in organic solvents, and very much fewer studies were reported in aqueous environments. The polymerization strategy was successfully demonstrated in water with or without oxygen-free conditions and resulted in structure-controlled polymers. We observed that the fluorescence of DCDPP-2TPA was intensified linearly with an increase in the degree of polymerization.