Bioinspired nano-fishnet structural construction for ultra-high dynamic toughness of carbon nanotube composite films

Structure design and interlocking construction are expected to generate desirable mechanical properties of advanced carbon nanotube (CNT) film for their impact protective applications. However, inadequate orientation and weak interlocking network often suffer from the large difference between the measured and theoretical mechanical properties. Here, we introduced a bioinspired nano-fishnet construction strategy to accurately control the alignment and interlocking state of CNT in the film. The strategy creates an aligned and densified structure as well as strong interlocking network via coordinated regulation of stretching and p-phenylene benzobisoxazole (PBO) infiltration. The developed PBO-CNT film shows excellent dynamic mechanical properties with a dynamic tensile strength of 4.92 ± 0.2 GPa and a toughness of 118.96 ± 9.78 MJ·m⁻³ with the ability to support weights up to 166,667 times its own. In addition, the relationship of structural regulation strategies and enhancement mechanisms of composite PBO-CNT film has been further revealed. This work establishes a structural design paradigm for optimizing the dynamic performance of carbon-based materials in protection management.