Laponite nanosheets(XLP)@Graphene(GN) Nanocomposite Conductive Hydrogels Based on Cellulose for Flexible Sensing Applications

This study utilized ionic liquids (ILs) to exfoliate Laponite nanosheets(XLP), altering the interlayer spacing of XLP, thus significantly improving its dispersibility and stability. More importantly, ILs can also benefit the dispersibility of graphene (GN) as well. The synergistic effects of sodium carboxymethyl cellulose (CMC), acrylamide, acrylic acid, SMA, and XLP significantly enhanced the mechanical properties of the hydrogel. At the same time, evenly dispersed GN enhanced the conductivity and sensing ability of the hydrogel dramatically. The hydrogel's multi-network structure, including physical cross-linking, chemical cross-linking, hydrophobic associations, and hydrogen bonding interactions, exhibited excellent mechanical performance and flexibility. The hydrogel sensors demonstrated excellent strain sensing capabilities, effectively responding under various strain conditions with high sensitivity and stability over a wide range of strains. Notably, the hydrogel sensors showed good responsiveness and repeatability in detecting human joint movements (wrist, elbow, knee), allowing for the differentiation of different joint motions. In summary, the P(AM-co-AA)/SMA/CMC/XLP/GN hydrogel, with its excellent dispersibility, mechanical properties, and sensing capabilities, exhibits great potential for applications in flexible sensors and wearable devices. This multi-mechanism enhancement strategy provides an effective method and theoretical foundation for designing high-performance hydrogel materials. Future research can further optimize the material's properties and expand its applications in other fields.