Ultrawide Modulus-Tunable Room-Temperature Phosphorescent Polymer Blends

Developing room-temperature phosphorescence (RTP) materials with tunable mechanical properties remains challenging. Herein, we report a facile strategy for achieving RTP with a tunable modulus via heterogeneous matrix construction through physical blending of polystyrene (PS) and polyethylene glycol (PEG). A β-diketonate phosphor (G), non-emissive in pure PS or PEG under air, exhibits a bright yellow-green afterglow in the PS/PEG blend. Phosphorescence performance (afterglow duration: 0.8−3.3 s) depends on the dye concentration, molecular weight of PEG, and PS/PEG ratio. Remarkably, the shear modulus of the blend system can be continuously tailored from 4 × 10−2 Pa to 5 × 108 Pa, covering flowable liquids all the way to rigid solid states, simply by tuning the PEG molecular weight and blending composition. This work integrates tunable mechanical properties with efficient RTP within a single system, opening possibilities for anti-counterfeiting and information encryption.