Stable and Elastic Electromagnetic Interference Shielding Composites with Microtubule‐Like Silver Nanoparticles via Swelling‐Dissolution Strategy

Elastic composites with robust electromagnetic interference (EMI) shielding effectiveness (SE) play a pivotal role in electronic systems by ensuring their normal operation and preventing information leakage. However, obtaining an optimal equilibrium between exceptional resilience and superior EMI SE presents considerable challenges in elastic composite development. In this study, a novel swelling‐dissolution strategy is proposed to construct a microtubule‐like silver nanoparticle (AgNP) 3D conductive network in polydimethylsiloxane (PDMS). The PDMS/AgNP composites exhibited outstanding electrical conductivity (2511.9 S/m) and superior EMI shielding capability (111.1 dB), with a remarkably low reflection loss (1.43 dB). Moreover, the PDMS/AgNP composites exhibit excellent strain recovery ratios (≈99%) over a wide temperature range (−40 to 130 °C) and under substantial compression deformation (50% strain). Even after exposure to more challenging environments—including different liquid environments and multiple compression among others—the EMI shielding performance remains at more than 92% of its initial level. The PDMS/AgNP composites simultaneously achieve robust compression performance and ultrahigh EMI shielding capability, demonstrating their enormous potential as EMI shielding elastomeric gaskets in extreme environments.