Ultralong Organic Phosphorescent Foams with High Mechanical Strength.

Ultralong organic phosphorescence (UOP) has aroused enormous interest in recent years. UOP materials are mainly limited to crystals or rigid host-guest systems. Their poor processability and mechanical properties critically hamper practical applications. Here, we reported a series of ultralong phosphorescent foams with high mechanical strength. Phosphorescence lifetime of the foam can reach up to 485.8 ms at room temperature. Impressively, lightweight gelatin foam can bear a compressive pressure of 4.44 MPa. Moreover, phosphorescence emission of polymer foam can be tuned from blue to orange through varying the excitation wavelength. Experimental data and theoretical calculations revealed that ultralong phosphorescence was ascribed to the fixation of multiple hydrogen bonds to the clusters of carbonyl groups. These results will allow for expanding the scope of luminescent foams, providing an ideal platform for developing ultralong phosphorescent materials with high mechanical strength.