Organic‒Inorganic Multiscale Crosslinking Assembly for Ultrahigh‐Toughness Nanocomposites

Abstract Strength and toughness have traditionally been regarded as mutually exclusive, but simultaneously achieving both high strength and high toughness in organic‒inorganic nanocomposites remains a significant challenge. Inspired by natural nacre and bone, inorganic ionic oligomers and organic molecular chains are employed to achieve multiscale crosslinking assembly, advancing from the ionic‐molecular level to nanolines, nanorods, nanofibers, microfibers, and ultimately to nanocomposite films and bulk nanocomposite materials. This process results in a highly integrated organic‒inorganic hierarchical ordered structure, imparting exceptional record‐breaking ultrahigh toughness (558.90 ± 34.84 MJ m −3 ), excellent tensile strength (353.84 ± 18.77 MPa), and fracture energy (2.93 MJ m −2 ) to the nanocomposite films. The resulting bulk nanocomposite exhibits outstanding bending mechanical properties (a maximum bending stress of 207.17 ± 12.37 MPa, and a bending energy of 37.62 ± 7.33 MJ m −3 without fracture), exceptional fatigue resistance, and remarkable toughness in extreme environments (e.g., −196 and 200 °C). Furthermore, the nanocomposites can undergo hydrothermal‐induced recycling and regeneration owing to their noncovalent crosslinking nature. Consequently, these nanocomposites exhibit significant potential for applications in high‐performance structural engineering materials. The proposed organic‒inorganic multiscale crosslinking assembly tactic based on inorganic ionic oligomers presents a promising approach for the fabrication of ultrahigh‐toughness nanocomposites.