Compressible, durable and conductive polydimethylsiloxane-coated MXene foams for high-performance electromagnetic interference shielding

Lightweight and compressible electromagnetic interference (EMI) shielding polymer nanocomposites are urgently required to solve increasingly serious electromagnetic pollutions. Two-dimensional transition metal carbides and nitrides (MXenes), especially Ti3C2Tx, are ideal candidates for constructing highly efficient conduction networks in polymer matrices due to their intriguing layered structure and high electrical conductivity. Herein, compressible and electrically conductive polydimethylsiloxane (PDMS)-coated MXene foams are fabricated by preforming three-dimensional (3D) MXene aerogel architectures assisted with sodium alginate (SA) followed by coating a thin layer of PDMS to enhance structural stability and durability of the porous architectures. Consequently, the lightweight MXene/SA hybrid aerogel achieves an outstanding conductivity of 2211 Sm-1 and a high average EMI shielding efficiency of 70.5 dB. Furthermore, the PDMS coating effectively endows the 3D conductance network with excellent compressibility and durability. The PDMS-coated MXene foam with 6.1 wt% of MXene reserves its high EMI shielding efficiency of 48.2 dB after 500 compression-release cycles. The lightweight, compressible and conductive PDMS-coated MXene foam is thus promising for applications in EMI shielding gaskets, wearable electronics, sensors and other specific areas.