Lanthanide-polyoxometalate-based anti-swelling luminescent conductive organohydrogel for information encryption and underwater sensing

Luminescent hydrogels have attracted great research interests in information encryption for their unique physicochemical properties and design versatility. However, the relatively limited functionality of luminescent hydrogels constrains their practical applications. Consequently, the development of multifunctional stimulus-responsive hydrogels has become increasingly imperative. Introducing conductive property into luminescent hydrogels is conducive to expanding their functional applications. Herein, a luminescent conductive organohydrogel with multifunctional was prepared through covalent crosslinked network supplied by poly(2-hydroxyethyl methacrylate) (PHEMA) and non-covalent crosslinked network supplied by polyquaternium-10/Na 9 EuW 10 O 36 (JR-400/EuW 10 ) via solvent exchange method. The acquired PHJ 0.06 EE organohydrogel exhibits reversible luminescent switching behavior upon HCl/NH 3 stimuli. Due to microphase separation, its transparency demonstrates significant variation across different solvents environments. These properties enable it to be used as an information storage device. Combining reversible luminescent switching property with transparency changes achieves advanced information encryption. Furthermore, the organohydrogel exhibits outstanding mechanical properties, anti-freezing property, anti-drying property, anti-swelling property (equilibrium swelling rate in water after 15 days is −1.51%) and adhesive property. Importantly, after soaking in water for 24 h, the organohydrogel functions as a flexibility wearable sensor with good strain sensitivity (GF = 3.321), pressure sensitivity (S = 0.975 kPa −1 ), rapid response, stable and repeatable electrical signals. It can monitor motions in both air and underwater environments while it can transmit information via Morse code in both conditions. Combining luminescent switching with conductivity properties achieves information encryption transmission. This work provides a novel strategy for preparing anti-swelling luminescent conductive organohydrogel, revealing its potential applications in information encryption and underwater sensing.