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.