Plant-inspired multifunctional fluorescent cellulose nanocrystals intelligent nanocomposite hydrogel

Intelligent hydrogel has great application potentials in flexible sensing and artificial intelligence devices due to its intrinsic characteristics. However, developing an intelligent hydrogel with favorable properties including high strength, superior toughness, excellent conductivity and ionic sensing via a facile route is still a challenge. Herein, inspired by biologically chelating interactions of phytic acid (PA) in plants, a plant-inspired versatile intelligent nanocomposite hydrogel was readily fabricated by incorporating PA into the interface of fluorescent cellulose nanocrystals (F-CNC). Under PA "molecular bridge", the hydrogel simultaneously realized superflexibility (1000 %), high strength, superb self-healing ability, remarkable fluorescence and chloride ion sensibility as well as good ionic conductivity (2.4 S/m). The hydrogel could be assembled as a flexible sensor for real-time monitoring of human motion with excellent sensitivity and stability since high sensitivity toward both strain and pressure. F-CNC acted as a functional trigger could confer the hydrogel good fluorescence and high sensitivity toward chloride ion. This design confirms the synergy of F-CNC in boosting strength, ionic sensing, and ionic conductivity, addressing a long-standing dilemma among strength, stretchability, and sensitivity for intelligent hydrogel. The one-step incorporating tactic under mild ambient conditions may open an innovative avenue for the construction of intelligent hydrogel with novel properties.