A dual-crosslinking strategy for building photoluminescence hydrogel with toughness, self-recovery, and two-color tunability

The development of tenacity photoluminescent (PL) hydrogels is very great significance to promote the application of optical technology in hydrogel. Herein, we report a high-toughness PL hydrogel that combines synthetic hydrophilic lanthanide complex (LCs) and tannic acid (TA) with polyvinyl alcohol (PVA) by frozen-thawing. The resulting hydrogel has high mechanical strength (1194.46-kPa tensile strength, 1266.17-kJ m −3 toughness energy, 1915.58-kPa compressive strength, and 269.79-kJ m −3 energy dissipation at 80% compression), excellent self-recover and anti-fatigue performance, good photoluminescence, and switchable functions under UV light, showing red (254 nm) and green (365 nm), respectively. The design strategy offers a new approach for the preparation of multifunctional and tenacity PL hydrogels.