Mechanical Behavior and Fracture Mechanisms of MXene/PVDF Nanocomponsites: In Situ Characterization and Multiscale Analysis

ABSTRACT

The integration of two‐dimensional (2D) MXene nanosheets into polyvinylidene fluoride (PVDF) matrices enables the design of multifunctional nanocomposites with enhanced properties. However, most attention has been dedicated to their electrical and dielectric characteristics, with information about the effect of MXene on mechanical properties being limited. This study systematically investigates the mechanical performance, fracture behavior, and interfacial mechanics of PVDF‐based composites containing from 0.25 to 3 wt.% Ti ₃ C ₂ T _x MXene using experimental characterization and finite element modeling. Multiscale characterization, including SEM, micro‐CT, XRD, and Raman spectroscopy, including in situ SEM and Raman spectroscopy during tensile testing, showed that optimal MXene incorporation (∼1–1.5 wt.%) nearly doubles tensile strength and significantly improves stiffness compared to pristine PVDF, while reducing elongation at break from 12.3% to 1–2% due to filler‐induced chain confinement. Fracture analysis revealed that MXene flakes promote crack deflection, branching, and interfacial sliding, thereby enhancing energy dissipation and altering the failure mode from ductile to a multi‐stage fracture process. In situ Raman spectroscopy confirmed effective stress transfer at the MXene–polymer interface up to a 1.3% strain. Finite element modeling using cohesive zone approaches complemented these findings and highlighted the critical roles of interfacial strength, flake aspect ratio, and alignment on mechanical reinforcement and damage evolution. Strong interfaces and well‐aligned, high‐aspect‐ratio flakes maximize load transfer and tensile strength, while weak interfaces and filler aggregation undermine performance. These findings establish quantitative design principles for MXene–polymer composites, demonstrating that optimized filler content, alignment, and interfacial bonding can nearly double strength and stiffness, paving the way for mechanically strong multifunctional MXene‐based films for flexible electronics, sensors, and other devices.