Ti₃C₂ MXene as a new nanofiller for robust and conductive elastomer composites

Ti₃C₂ MXene with a layered 2D structure was applied as a novel functional filler in rubber for the first time. A facile and green method was proposed to fabricate rubber/Ti₃C₂ nanocomposites via a freeze-drying & mechanical mixing process. It was found that Ti₃C₂ with ∼1 nm thickness fabricated by etching Al from Ti₃AlC₂ phases can be dispersed in styrene-butadiene rubber (SBR) evenly in a single-layered state. Mechanical strength and electrical and thermal conductivities of the rubber nanocomposites were remarkably enhanced by the incorporation of Ti₃C₂, showing dramatic improvement compared with reduced graphene oxide (rGO) reinforced rubber composites. For example, the thermal conductivity of SBR nanocomposites with 3 wt% rGO was 0.265 W m^-1 k^-1, while that of SBR nanocomposites with only 1.96 wt% Ti₃C₂ reached 0.477 W m^-1 k^-1. Meanwhile, the resistance of rubber/Ti₃C₂ nanocomposites was stable under complex deformation and their sensitivity was well recovered during stretching/shrinking cycles under large strain. Moreover, it was discovered that incorporating Ti₃C₂ in rubber nanocomposites dramatically improved the wet skid resistance and thermal stability without increasing the rolling resistance. Ti₃C₂ MXene with a distinctive structure and properties as well as uniform dispersion will have more potential for the preparation of high-performance rubber nanocomposites, especially for green tires and flexible sensors.