Printable, room-temperature self-healing and full-color-tunable emissive composites for transparent panchromatic display and flexible high-level anti-counterfeiting

The luminescent self-healing materials have a significant prospect in optical device applications such as biosensing, multicolor displays, and high-level anti-counterfeiting. Herein, a novel printable, room-temperature self-healing and full-color-tunable luminescent composites were developed through the noncovalent binding of physically cross-linked p(HFBM-co-SBMA)/EMITFSI and excitation-orthogonalized RGB-switchable UCNPs. According to a strategy of Selective photon capture (SPC), the RGB-switchable core-sextuple-shell UCNPs were first established for red/green/blue-switchable luminescence under three different excitations (980/808/1550 nm) and even full-color output through the combination of 980/808/1550 nm light. The copolymer p(HFBM-co-SBMA), pre-synthesized via free radical polymerization, was incorporated with ionic liquid EMITFSI to formulate room-temperature self-healing material owing to ion–dipole interactions between EMITFSI and p(HFBM-co-SBMA). Afterward, the integration of 30 wt% EMITFSI copolymer and fluothane-modified UCNPs resulted in the formation of the final full-color-tunable luminescent self-healing composites, which not only exhibited superior Young’s modulus and healing efficiency than some previously reported room-temperature self-healing materials, but also realized full-color-tunable emissions under ternary 980/808/1550 nm excitations. Significantly, the luminescent self-healing composites, which also exhibited colorless character and high transmittance, could be employed as printable inks for making various luminescent patterns (including clock, flower, and QR code) on flexible substrates via convenient and cost-effective screen-printing technique. As the results of proofs of concept, these luminescent patterns displayed fantastic viewing capability and highly secured property, which showed enormous potential of the proposed luminescent self-healing composites in flexible panchromatic display and high-security-level anti-counterfeiting. To our knowledge, this work provides the strategy for constructing full-color-tunable self-healing luminescent composites for the first time. Undoubtedly, the well-designed luminescent self-healing materials will provide new insights and guidance for exploiting the new generation of flexible optical devices, especially multicolor displays and anti-counterfeiting devices.