Tough and highly stretchable multifunctional ionogels based on phase-separated structure and nanocellulose macromolecular covalent cross-linker

Recently, ionogels have attracted significant attention in the field of flexible wearable sensors. However, obtaining high-mechanical-strength ionogels is still a challenge. Herein, we use nanocellulose as a macromolecular covalent cross-linker combined with a phase-separation design strategy to prepare a highly tough and multifunctional ionogel. This ionogel has excellent mechanical properties, including high tensility (975%), strength (3.29 MPa), and toughness (13.15 MJ m⁻³). The introduction of Zn²⁺ induces the formation of a dynamic cross-linked structure, endowing the ionogel with good self-healing properties (up to 60%). Due to the rich functional groups in the ionogel, it exhibits robust self-adhesive properties (850 J m⁻²). With these properties, this ionogel can be used to fabricate strain sensors to detect human motion, and simply spraying curcumin on the gel surface also allows it to monitor the pH of sweat during motion. This work broadens the multifunctional applications of ionogels and provides an opportunity for the high-value utilization of nanocellulose.