A Glassy Hydrogel Platform for Color-Tunable Room-Temperature Phosphorescence via Unmodified Aromatic Compounds Encapsulation and Arbitrary Shape Programming

Realizing full-color room-temperature phosphorescence (RTP) under aqueous conditions remains a significant challenge due to the inherent difficulty of stabilizing hydrophobic phosphors within water-based matrices, let alone for unmodified commercial hydrophobic aromatic compounds. In this work, we introduce a versatile glassy hydrogel platform engineered through a solvent exchange-induced nanoscale phase separation strategy, which enables the stable encapsulation of various commercial aromatic compounds within a rigid polymer network. The resulting hydrogels exhibit tunable full-color RTP with long-lived lifetimes, enhanced emission underwater, and outstanding mechanical robustness. In addition to their plastic-like rigidity, these glassy RTP hydrogels display shape-memory characteristics and allow for programmable 2D/3D structural reconfiguration. Notably, they facilitate multidimensional information encryption through multicolor triplet-to-singlet Förster resonance energy transfer (TS-FRET) and enable high-resolution spatial patterning. This work offers a general strategy for constructing RTP hydrogels and hydrogel-derived plastics, opening promising avenues for advanced anticounterfeiting, optical sensing, and underwater photonic applications.