Transparent and lightweight electromagnetic shielding film with resistance to harsh conditions through interpenetrating encapsulation of silver nanowires network

Optically transparent electromagnetic interference (OTEMI) shielding materials are garnering significant attention due to their dual capabilities of providing electromagnetic interference (EMI) shielding while maintaining optical transparency. Beyond high shielding efficiency, the materials also require lightweight, ultra-thinness, flexibility, and reliability for extreme conditions applications like industrial and aerospace scenarios, which challenges most existing EMI shielding materials. Herein, we utilize the openings in the percolating silver nanowires network to realize the interpenetrating crosslink of polyamide acid, which enables the in-situ, damage-free encapsulation of the vulnerable conductive network and forms a lightweight OTEMI shielding film with exceptional stability. The 8 μm EMI shielding films show 29–46 dB shielding effectiveness in the 12–18 GHz range, with variable visible light transmittance (45 %-86 %@550 nm), while being capable of withstanding a broad temperature variation from 220 °C to − 170 °C. Moreover, the solution-processed film possesses excellent bending stability and chemical corrosion resistance, showing its unique applications in harsh conditions inaccessible to humans.