Aggregation-induced emission polymer systems with circularly polarized luminescence

Functional materials with circularly polarized luminescence (CPL) have attracted tremendous attention due to their promising applications in three-dimensional displays, chiral recognition and catalysis, photoelectronic devices, contrast imaging, information encryption, and other fields. Among various CPL-active materials, polymeric systems with aggregation-induced emission (AIE) have emerged as excellent candidates because of their efficient aggregate-state fluorescence, large solid-state dissymmetry factor, excellent processibility, diversified self-assembly behaviors, and readily switchable CPL properties. This review summarizes and discusses the recent progress as well as future perspective of diverse AIE polymer systems with CPL, including CPL-active covalent AIE polymers, CPL-active supramolecular AIE polymers, and AIEgen/polymer composites with CPL. According to the location or introduction method of AIEgen in polymer structures, this review further divides CPL-active covalent AIE polymers into three categories, including polymers with AIEgen in main chains, polymers with AIEgen in side chains, and CPL-active polymers with clusterization-triggered emission. CPL-active supramolecular AIE polymers are discussed based on the driving force for the formation of supramolecular polymers, including host-guest interactions, metal coordination, and other non-covalent interactions. Moreover, examples on the construction of CPL-active AIEgen/polymer composites by physically mixing AIEgens with chiral (supra)polymers are also presented. This review is anticipated to provide readers with an overall view on the design strategies of CPL-active AIE polymers, and facilitate further research on the development of CPL materials and AIE polymers with advanced applications.