Silicone-Enhanced Polyvinyl Alcohol Hydrogels with Intrinsic Photoluminescence and High Mechanical Intensity

Photoluminescent hydrogels show great potential in the fields of information storage and security, environmental monitoring and protection, in vivo noninvasive monitoring, drug delivery, and tissue engineering. Current fluorescent hydrogels are prepared by coupling or doping fluorescent units, such as semiconductor quantum dots, metal–ligand complexes, lanthanide ions, and organic dyes, into polymer hydrogel matrices. However, conventional fluorescent hydrogels have intrinsic defects, including poor photostability, toxicity, and low mechanical strength, which severely limit their applications. In this study, we developed an intrinsically photoluminescent dual-network hydrogel with excellent mechanical properties. Poly(vinyl alcohol) formed the first hydrogel network, with aminopolysiloxane and citric acid forming the second (APSi network) via amidation-cross-linking chemistry. The introduction of the APSi network endowed the hydrogel with photoluminescence and enhanced mechanical properties, which can be adjusted by changing the APSi-network content. The innovatively developed hydrogel possesses intrinsic photoluminescence, excellent light stability, tunable mechanical properties, and is highly biocompatible, which highlights its potential applicability in many fields. This study provides a simple and versatile strategy for preparing novel fluorescent hydrogels with multidisciplinary application potential.