Intrinsically N-doped phthalonitrile-derived carbon aerogel composites for integrated electromagnetic interference shielding, thermal protection, and mechanical robustness

Porous phthalonitrile-derived carbon materials (PNCM) are an emerging family of multifunctional carbon characterized by high porosity and intrinsically N-doped skeletons. These N-rich frameworks enable highly efficient electromagnetic interference (EMI) shielding without the need for additional nitrogen sources. However, existing pore-forming methods (e.g., foaming, templating) have limited controllability and designability in structural construction and functional integration. This paper proposes an aerogel-engineering strategy to endow PNCM with diverse multifunctionality. Specifically, phthalonitrile polymer aerogels and their corresponding carbon aerogels (PNCA) are prepared using a universal sol–gel–drying–carbonization route. After carbonization at 1000 °C, an intrinsically N-doped amorphous carbon aerogel monolithic material (C1000) can be obtained, which has a hierarchical porous structure and a specific surface area of 241 m 2  g −1 . C1000 exhibits excellent EMI shielding effectiveness of up to 110 dB and a low thermal conductivity of 0.09 W m −1  K −1 . Furthermore, the combination of aerogel-engineering strategy and co-carbonization process facilitates the construction of fiber-reinforced carbon aerogel composites. The resulting PNCA composite maintains EMI shielding performance while also exhibiting improved mechanical stability and ablation resistance. This work has demonstrated a multifunctional aerogel-engineering strategy for constructing porous PNCM, achieving broader structural tunability and integrated EMI shielding, thermal protection, and mechanical robustness.