Insulating and flexible electromagnetic-shielding nanofiber composite film for direct wrapping on electronics even in harsh conditions

Current electromagnetic interference (EMI) shielding materials mainly depends on electrical conductivity, it still remains great challenges to avoid short-circuit risks and assemble into macroscopic films with strong mechanical strength. To address these problems, we rationally design and prepare a multilayer-structured EMI shielding nanocomposite film (P-Co-MX), where MOF-derived porous Co–C as the magnetic layer and MXene as the conductive layer are sandwiched between two poly(m-phenylene isophthalamide) (PMIA) nanofiber membranes, with the PMIA membranes as insulating and protection layers. Benefiting from the rational design of multi-layer structure, P-Co-MX exhibits high EMI shielding effectiveness in X-band (8.2–12.4 GHz) with absorption-dominated EMI shielding feature. Owing to the protection of PMIA nanofiber layers, P-Co-MX shows high resistivity, excellent flexibility and stable EMI shielding performance even in harsh conditions, including 200 ℃ high temperature, − 196 ℃ ultralow-temperature and corrosive conditions (pH = 3). These unique features allow for direct wrapping on the signal lines in highly miniaturized and flexible electronics to solve EMI issue.