Highly Tough, Stretchable, and Recyclable Ionogels with Crosslink-Enhanced Emission Characteristics for Anti-Counterfeiting and Motion Detection

Traditional luminescent ionogels often suffer from poor mechanical properties and a lack of recyclability and regeneration, which limits their further application and sustainable development. Herein, a luminescent ionogel with strong mechanical properties and good recyclability has been designed and fabricated by introducing dynamic coordination bonds via in situ one-step crosslinking of acrylic acid in ionic liquid of 1-ethyl-3-methylimidazolium diethylphosphate by zinc dimethacrylate. Due to the special crosslinking of dynamic coordination bonds along with the hydrogen bond interaction, the as-prepared ionogel displays excellent stretchability and toughness, good self-adhesiveness, fast self-healability, and recyclability. Interestingly, the obtained ionogels exhibit tunable photoluminescence caused by the crosslink-enhanced emission (CEE) effect from the coordination bonds. Importantly, ionogels can be applied in information storage, information encryption, anti-counterfeiting due to their simple and in situ preparation method, and their special fluorescence performances. Moreover, an ionogel-based wearable sensor has rapid response time and a high gauge factor of 3.22 within a wide strain range from 1 to 700%, which can monitor various human movements accurately from subtle to large-scale motions. This paper offers a promising way to fabricate sustainable functional ionic liquid-based composites with CEE characteristics via an in situ one-step polymerization method.