Hybrid Ti₃C₂T _x MXene and Carbon Nanotube Reinforced Epoxy Nanocomposites for Self-Sensing and Structural Health Monitoring

Herein we present the transformative effects of multiwall carbon nanotube (MWCNT)-MXene hybrid nanofillers on the mechanical, electrical, and piezoresistive properties of the resulting epoxy nanocomposites. The utilization of the MWCNT-MXene hybrids significantly improves the dispersion of fillers within the epoxy matrix, effectively eliminating the agglomeration of individual fillers and improving the stress transfer efficiency. With just 1 wt % MWCNT-MXene hybrid, we observed improvements in the Young's modulus and the flexural modulus, which increased by 31 and 28%, respectively, when compared to neat epoxy. Furthermore, the fracture toughness of these composites was 84.5% higher than that of neat epoxy, primarily attributed to crack deflection and filler debonding mechanisms. The hybrid composites exhibited increased piezoresistive sensitivity during tensile, flexural, and fracture tests due to the creation of a percolating network of MWCNT and MXene nanoplatelets. Our findings have implications for the development of advanced hybrid materials, holding promise for applications in strain sensors and self-sensing structures.