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Some marine animals form long‐lived luminescence for predation, communication, camouflage, and anti‐predation. These marine animals demonstrate soft nature, sustainable glowing, and underwater emission, which are difficult to achieve in synthetic room temperature phosphorescence (RTP) materials. Inspired by these marine animals, here the study reports RTP hydrogels that show long‐lived phosphorescence (lifetime >500 ms and afterglow >10 s) in water. Exceptional underwater mechanical properties are simultaneously achieved, including tensile strength of 5.1 MPa, tensile strain of 452%, and toughness of 19.3 MJ m−3. The key to this achievement lies in the in situ phase separation microarchitecture formed between polyacrylamide (PAM) and its partial hydrolysates, which confines the motions of polymer chains and protects vulnerable triplet excitons from quenching of water. Such a strategy shows the merits of facile fabrication without laborious synthesis. In addition, these RTP hydrogels offer repeatable photoprinting and highly stability in water, providing a versatile platform for underwater applications of RTP materials, including information encryption and camouflage of marine animals. [ABSTRACT FROM AUTHOR]

Polymeric room‐temperature phosphorescence (RTP) materials especially multicolor RTP systems hold great promise in concrete applications. A key feature in these applications is a triplet charge transfer transition. Aromatic electron donors and electron acceptors are often essential to ensure persistent RTP. There is much interest in fabricating non‐aromatic charge‐transfer‐mediated RTP materials and it still remains a formidable challenge to achieve color‐tunable RTP via charge transfer. Herein, a charge‐transfer‐mediated RTP material by embedding quinoline derivatives within a non‐aromatic polymer matrix such as polyacrylamide (PAM) or polyvinyl alcohol (PVA) is developed. Through‐space charge transfer (TSCT) is achieved upon alkali‐ or heat treatment to realize a long phosphorescence lifetime of up to 629.90 ms, high phosphorescence quantum yield of up to 20.51%, and a green‐to‐blue afterglow for more than 20 s at room temperature. This color‐tunable RTP emerges from a nonaromatic polymer to single phosphor charge transfer that has rarely been reported before. This finding suggests that an effective and simple approach can deliver new color‐tunable RTP materials for applications including multicolor display, information encryption, and gas detection. [ABSTRACT FROM AUTHOR]

The development of tough, stretchable and long‐lived room temperature phosphorescence (RTP) materials holds great significance for manufacturing and processing photoluminescent materials, but limited techniques are available to profile their mechanics‐photophysics correlation. Here we report glassy ionogels, and their mechanical properties and photophysical properties are fused by dynamic mechanical analysis (DMA), functioning like a human brain that perceives a material instantaneously by linking sensory perception and cognition. Depending on two special temperatures presented in DMA curves, Tloss (the peak of loss modulus (E”)) and Tg (glass transition temperature), the ionogels can vary from being either tough with persistent phosphorescence, extensible with effective phosphorescence or resilience with inefficient phosphorescence. Leveraging this method, we achieve stretchable and long‐lived RTP ionogels with tensile yield strength of 53 MPa, tensile strain of 497 %, Young's modulus of 782 MPa, toughness of 111.2 MJ/m3, and lifetime of 113.05 ms. Our work provides a simple yet powerful method to reveal the mechanics‐photophysics correlation of RTP ionogels, to predict their performance without laborious synthesis and characterization, opening new avenues for applications of RTP materials, including applications in harsh conditions (257 K or 347 K), shape memory and shape reconstruction. [ABSTRACT FROM AUTHOR]