Flexible multifunctional polydimethylsiloxane composites with segregated structure fabricated by hydrophobic interaction for efficient electromagnetic interference shielding

The formation of segregated structure has been demonstrated as an effective strategy for achieving exceptional electromagnetic interference (EMI) shielding performance at low filler loadings. However, the acquisition of polymer particles and the formation of interactions with conductive fillers remain significant challenges for polydimethylsiloxane, which are crucial to the construction of a segregated structure. In this work, MXene sheets were functionalized and assembled onto the surface of polydimethylsiloxane microspheres via hydrophobic interaction. Subsequently, functionalized MXene/polydimethylsiloxane (FMP) composites with a segregated structure were fabricated by filtration and hot-pressing. The FMP composite containing 8.22 wt.% MXene exhibited a high electrical conductivity of 99.4 S·m^-1 and a satisfactory EMI shielding effectiveness/thickness (EMI SE/d) of 31.3 dB·mm^-1. Furthermore, the FMP composite demonstrated excellent reliability with over 90% retention of EMI shielding effectiveness under harsh environments such as ultra-high/low temperatures and acidic/alkaline solutions. Additionally, the photothermal conversion performance of FMP composites and the capacitive sensing performance of the sensor based on FMP composites indicated their potential for managing body temperature and monitoring human movement. Consequently, FMP composites show great promise in wearable electronics for effective electromagnetic interference shielding, thermal management and capacitive sensing.