Micromechanics of Ti3C2Tx MXene Reinforced Poly(vinyl Alcohol) Nanocomposites

The key to effective mechanical reinforcement in polymer nancomposites lies within the stress transfer mechanisms and the distribution of the nanofillers within a polymer matrix. In this work, the micromechanics of Ti3C2Tx MXene-reinforced poly(vinyl alcohol) (PVA) nanocomposites have been studied in detail. Ti3C2Tx MXene/PVA nanocomposites were prepared by solution blending. The spatial orientation of Ti3C2Tx MXene in the nanocomposites was characterized by polarized Raman spectroscopy and the orientation factor was correlated to the effective Young's modulus of the flakes through well-established micromechanical theories. The mechanical properties of the nanocomposites were evaluated by tensile testing. A 27% increase in Young's modulus and a 24% improvement in tensile strength were achieved by addition of only 0.6 wt% Ti3C2Tx. Efficient stress transfer from the polymer matrix to Ti3C2Tx MXene in bulk nanocomposites has been observed through strain-induced Raman band shifts for the first time. The effective Young's modulus of the MXene nanoplatelets was calculated to be in the order of 300 GPa, in good agreement with the values derived from the application of micromechanical models.