High-Toughness Epoxy-Based Composites with a Bioinspired Three-Dimensional Interconnected Skeleton for Photothermal Conversion Applications

Advanced epoxy (EP)-based composites, retaining excellent physical and mechanical properties, are in demand in many high-end devices, such as fan blades of aeroengines. However, the irreconcilable conflict between stiffness and toughness within an EP often leads to catastrophic brittle fracture. Herein, inspired by the medulla skeleton of wing feathers of <i>Milvus migrans</i>, bioinspired EP-based composites (BECs) were obtained via integrating functionalized three-dimensional interconnected skeleton into a brittle EP. The BEC's fracture toughness is enhanced by 111.43%. Significantly, the maximum fracture toughness (<i>K</i>_JC) of the BEC is 3.5 times greater than that of the EP. Moreover, under 100 mW/cm² irradiation, the BEC can be heated from room temperature to 90 °C in 5 min, exhibiting excellent photothermal conversion capacity. The BEC expands the possible applications of conventional EP-based composites in engineering materials and energy management fields. The proposed bioinspired strategy provides a new avenue to design novel EP-based composites with strong mechanical properties and multifunction integration.