SiBCN/ZrN fiber with multiphase synergy for multifunctional EMI shielding in complex environments

As electromagnetic pollution and extreme environments increasingly threaten the operational stability of electronic devices, there is a pressing need for lightweight, flexible materials that integrate electromagnetic shielding, high-temperature tolerance, and intelligent sensing. Herein, solution blow spinning combined with a multiphase-synergy design was employed to in situ form ZrN during high-velocity airflow drawing and high-temperature pyrolysis, enabling the scalable fabrication of ultrafine SiBCN/ZrN composite nanofiber. The introduction of ZrN significantly enhances the electrical conductivity and thermal stability of the fibers, while also promoting increased porosity and specific surface area during pyrolysis. This creates a multi-phase synergistic conductive and polarization network, endowing the composite mats with excellent electromagnetic shielding performance (SE T reaching 35 dB and SSE of 346.5 dB·cm 3 ·g −1 ). Furthermore, the material exhibits good mechanical flexibility and cyclic stability, maintaining fast and reversible responses under high strain conditions, with a high sensitivity of 15.49 kPa −1 and a rapid response time of 83 ms, while retaining stable signals after more than 1000 cycles. Moreover, the intrinsic fire resistance of SiBCN and the chemical stability of ZrN endow the SiBCN/ZrN composite nanofiber with excellent ablation resistance, allowing them to maintain structural integrity even after exposure to a 1200 °C flame. The preparation strategy proposed in this study not only enables the large-scale construction of multifunctional SiBCN/ZrN composite mats but also provides new insights and material foundations for their applications in electromagnetic shielding, fire safety, and intelligent sensing in complex service environments.