Significantly improved dielectric and mechanical performance of Ti₃C₂T_x MXene/silicone rubber nanocomposites

MXenes are attracting great interest for their excellent electrical and mechanical properties. High dielectric constants have been achieved in polymer-based nanocomposites with MXenes as fillers, but these materials suffer from large dielectric losses. In this work, Ti₃C₂T_x MXene/silicone rubber (SR) nanocomposites were prepared because of the low dielectric loss of SR. The effects of Ti₃C₂T_x MXene nanosheets on the thermal stability, dielectric and mechanical performance of the nanocomposites were investigated. A dielectric constant of 6.2 accompanied by an extremely low dielectric loss of 0.001 at 10³ Hz frequency was obtained in the nanocomposites when 1.2 wt% Ti₃C₂T_x MXene was loaded. The enhanced dielectric properties are mainly attributed to the Maxwell-Wagner-Sillars effect and the microcapacitor model. Moreover, the thermal stability of the nanocomposites can reach 450 °C. Tensile strength of 430 kPa, elongation at break of 341% and reduced elastic module of 402 kPa were also obtained in the nanocomposite with 2 wt% Ti₃C₂T_x MXene. This work provides a method for fabricating polymer-based nanocomposites with excellent dielectric properties under low filling content, which is crucial for modern electronic applications.