Color-Tunable Circularly Polarized Room-Temperature Phosphorescence by Intermolecular Phosphorescence Resonance Energy Transfer in a Chiral Co-assembled Liquid Crystal Polymer Network

Circularly polarized room-temperature phosphorescent (CP-RTP) materials have been attracting great attention due to their potential applications in anticounterfeiting. In this study, we designed and synthesized a host-guest copolymer (PBXT) with strong phosphorescence emission and a long emission lifetime using a self-doping strategy. The co-assembled liquid crystal polymer networks (LCPNs)x-(RI/SI)y doped with PBXT demonstrated a stronger RTP emission and longer lifetime (τ = 148 ms). Among them, (LCPNs)0.91-(RI)0.09 showed strong CP-RTP signals (|gRTP| = 0.071) through chiral supramolecular co-assembly. By dropping Nile Red (NR) into (LCPNs)0.91-(RI/SI)0.09, the resulting [(LCPNs)0.91-(RI/SI)0.09]0.9925-(NR)0.0075 emitted intense red circularly polarized luminescence (CPL) of NR dye (λem = 636 nm and |gem| = 0.073) with a long lifetime (τ = 26 ms) under the regulation of an intermolecular phosphorescence resonance energy transfer (PRET) mechanism. Additionally, [(LCPNs)x-(RI/SI)y]m-(NR)n has been explored for applications in time-varying information encryption and quadruplex anticounterfeiting information encryption through the PRET progress.