Scalable Production of 24‐Hour‐Long Afterglow Plastics Through Molecular Doping Strategy

Abstract The development of polymeric afterglow materials has garnered significant interest due to their promising applications in sensing technologies, smart devices, and optoelectronic systems. However, conventional engineering plastics typically exhibit limited afterglow properties owing to rapid nonradiative decay processes under ambient conditions. This study presents a breakthrough in the fabrication of plastics with 24‐h‐long afterglow (HLA) properties through a molecular doping strategy compatible with industrial engineering processes. By utilizing aromatic plastics as electron acceptor and the matrix, spirofluorene derivatives are incorporated as electron donors and chromophore dopants via a melt blending technique, a widely established method in polymer manufacturing. The resulting doped plastics demonstrated green afterglow persisting for 24 h under ambient conditions. At 4 °C, the HLA lasted for up to 100 h after ceasing photoexcitation, setting a new benchmark for polymeric materials. Remarkably, these materials could be activated by natural sunlight and maintain a visible green afterglow for 5 h in ambient air. Mechanism studies revealed that the HLA phenomenon is associated with the formation of donor/acceptor exciplexes upon photoexcitation. Additionally, the HLA plastics exhibited exceptional mechanical flexibility and optical transparency, making them highly suitable for advanced applications in flexible displays and next‐generation wearable technologies.