Harnessing Sub1 nm GdOOH Nanowires for Synergistic Cross-Linking-Entanglement Engineering in High-Performance Polymer Composite Gels

Conventional polymer gels often suffer from the intrinsic trade-off among strength, toughness, and low-temperature stability, which severely limits their applications. Herein, a subnanowire (SNW)-induced cross-linking-entanglement synergistic strategy is proposed by incorporating GdOOH subnanowires (GdOOH SNWs) into a poly(acrylic acid) (PAA) network to construct a multiscale cooperative structure featuring dynamic coordination cross-linking and topological entanglements. Rheological analysis demonstrates that the introduction of GdOOH SNWs effectively prolongs network relaxation behavior and promotes the formation of a cross-linking-entanglement synergistic network. This synergy yields exceptional mechanical properties of the composite gel: 729% elongation at break, 367.3 kJ/m 3 toughness (5.65-fold enhancement over pure PAA), and 16.7-fold higher fracture energy (68.6 kJ/m 2 ) in notched samples, demonstrating superior crack resistance. The gel exhibits strong adhesion to diverse substrates (skin, metal, polymer) via hydrogen bonding, coordination, and mechanical interlocking. With optimized conductivity (0.054 S/m) and strain-sensitive response (gauge factor (GF) up to 0.899 at 500% strain), the gel-based sensor achieves high-fidelity monitoring of human motions (e.g., joint bending, vocalization). Notably, the composite gel also demonstrates remarkable frost resistance, maintaining high sensing performance even at −80 °C. This work pioneers a nanocomposite design paradigm leveraging entanglement-cross-linking balance, opening avenues for advanced electronic skins and wearable healthcare devices operable under harsh environmental conditions.