A room-temperature self-healing and mechanically robust siloxane elastomer via synergistic complexation and cation–π interactions for high-performance electromagnetic interference shielding

Abstract

The rapid development of flexible electronic devices and the growing concern over electromagnetic radiation pollution have created an urgent need for electromagnetic interference (EMI) shielding materials with both excellent mechanical performance and room-temperature self-healing capability. However, it is still a big challenge to meet this requirement. In this work, a room-temperature self-healing and mechanically robust supramolecular elastomer is designed by incorporating an electron-rich indole derivative and Fe³⁺ into a siloxane polymer via synergistic short-range complexation interactions between Fe³⁺ and the indole derivative and long-range cation–π interactions between Fe³⁺ and the indole derivative as cross-linking points. The resulting siloxane elastomer exhibits excellent mechanical properties (tensile strength of 2.86 MPa and elongation at break of 487%), strong adhesion (923 kPa), and remarkable self-healing efficiency (99%). Leveraging its adhesive property, the siloxane elastomer is integrated with silver nanowires (Ag NWs) to fabricate a composite film. The composite film demonstrates excellent self-healing and superior EMI shielding effectiveness of up to 70.83 dB. This work presents a convenient and rapid strategy for developing multifunctional materials for next-generation flexible electronics.