Integration of TpPa-1 COF and MXene in Chitosan-Based Aerogels for Impedance Matching and Electromagnetic Interference Shielding

MXene-based aerogels are promising for electromagnetic interference (EMI) shielding due to their lightweight nature and high conductivity. However, their practical application is often hindered by severe impedance mismatch and excessive secondary reflection. To overcome this limitation, we developed a multifunctional ternary composite aerogel (MTCA) via a synergistic self-assembly strategy. In this architecture, TpPa-1 covalent organic framework (COF) was grown in situ and integrated with MXene nanosheets within a chitosan matrix. The resulting hierarchical porous structure significantly optimizes impedance matching. Consequently, the optimized MTCA achieves an EMI shielding efficiency of 39.93 dB in the X-band, operating via an absorption-dominated mechanism. This performance stems from enhanced interfacial polarization at the MXene/COF heterojunctions and prolonged microwave propagation paths facilitated by multiple scattering within the porous network. Furthermore, the aerogel exhibits multispectral stealth capabilities: it demonstrates low infrared emissivity (ε = 0.50), superior thermal insulation (surface temperature of 28.7 °C under an 80 °C heat source), and effective visual camouflage adaptable to environmental backgrounds. This work presents a robust strategy for designing advanced stealth materials that integrate efficient absorption-dominant EMI shielding with multispectral compatibility.