Multifunctional polydimethylsiloxane composites with interpenetrating conductive segregated network for exceptional electromagnetic interference shielding

Polydimethylsiloxane (PDMS) segregated composites incorporating MXene as a conductive filler were demonstrated significant advancements in electromagnetic interference (EMI) shielding applications. However, the EMI shielding effectiveness (EMI SE) at low conductive filler contents remains a challenge that requires further optimization. In this work, PDMS@MXene microspheres were prepared via electrostatic interactions and then integrated with silver nanowires (AgNWs) to construct a PDMS@MXene/AgNWs interpenetrating conductive network. Subsequently, the PDMS@MXene/AgNWs (PMA) composites were fabricated by infiltrating the PDMS matrix into the interpenetrating network. Within the PMA conductive composites, MXene nanosheets formed a continuous conductive network, while AgNWs served as bridging connectors to enhance charge transfer efficiency. Notably, the PMA composite at low conductive filler loading of 7.12 wt% achieved an electrical conductivity of 118.60 S m⁻¹ and an impressive EMI shielding efficiency/thickness (EMI SE/d) of 39.33 dB mm⁻¹. Furthermore, the PMA composite exhibited exceptional EMI shielding stability under various harsh environments, including extreme temperatures and acidic/basic chemical environments. Additionally, the photothermal conversion performance of the PMA composite and the capacitive sensing performance of sensors based on PMA composites highlighted their potential applications in body temperature regulation and information transmission. This work provides a promising approach for designing PDMS-based multifunctional EMI shielding composites, which hold great promise for wearable electronic devices.