Chitin-based bamboo-inspired carbon aerogels enabling excellent absorption-dominated electromagnetic interference...

Achieving a balance between significant absorption capacity and rapid thermal diffusion is crucial for developing high-performance electromagnetic interference shielding materials. Inspired by the pits on straight holes of bamboo, an emulsion ice templating strategy was developed to fabricate bamboo-like carbon aerogels (BCA) based on chitin nanofibers, which demonstrated both a high absorption coefficient (A) and excellent thermal dissipation. Benefiting from the pits on straight holes, the BCA exhibited excellent diffuse reflection and scattering capabilities for electromagnetic waves, which facilitated the transition of the shielding mechanism from reflection-dominated-type to absorption-dominated-type, while effectively balancing the relationship between electrical conductivity, A, and electromagnetic interference shielding effectiveness (EMI SE). Specifically, BCA1-1100 exhibited an outstanding EMI SE of 73.9 dB, with a specific EMI SE value of 15,338.3 dB·cm²·g^-1 and an A of 0.61. The excellent EMI SE arose from multiple shielding mechanisms, including diffuse reflection, scattering, conduction loss, and polarization loss, which effectively absorbed electromagnetic waves. Meanwhile, the pits enhanced convective thermal transfer, facilitating the shift of thermal energy within the BCA from anisotropic to isotropic diffusion, thereby significantly dissipating the thermal energy generated by electromagnetic wave absorption. This biomimetic design strategy provided a novel solution to secondary electromagnetic reflection and thermal accumulation.