24‐Hour‐Long Afterglow from Single Polymer Chains Through Engineering‐Compatible One‐Pot Polycondensation Approach

We report the unprecedented observation of 24-h-long afterglow (HLA) emission from single polymer chains. The polymer chains were synthesized through a straightforward engineering-compatible one-pot polycondensation reaction. These polymers exhibit afterglow emissions exceeding 24 h under ambient conditions through charge separation and recombination mechanisms. Remarkably, these HLA polymers can be activated by sunlight and sustain a green afterglow for over 6 h at room temperature in air, rendering them suitable for practical engineering applications. Notably, the HLA is temperature-dependent, with lower temperatures substantially prolonging emission duration. At - 18 °C, afterglow persists for up to 10 days after ceasing photoexcitation, establishing these polymers as the longest-lasting afterglow polymeric materials reported to date. Moreover, the excellent processability of the 24-HLA polymers allows their facile fabrication into diverse forms including films and fibers using conventional polymer processing techniques, positioning them as promising candidates for flexible displays and wearable electronics.