Tunable interfacial shear strength of Ti3C2 MXene bilayers via controlled hydration: a molecular dynamics study

MXenes are conductive, surface-tunable 2D carbides/nitrides whose interlayer mechanics in realistic hydration are poorly quantified. Using molecular dynamics (LAMMPS, CVFF/IFF), we measure how intercalated water controls shear at OH-terminated Ti3C2 bilayers. We simulate five hydration states (dry→full monolayer) and, under incremental lateral loads, compute slip probabilities versus shear stress; logistic fits give median slip stress τ_0.5. Dry interfaces sustain ~103 MPa. At 25% coverage, sparse water solvates –OH groups and lubricates, reducing τ_0.5 to ~8 MPa. With added water, H-bond networks bridge the sheets and progressively restore load transfer: ~22 MPa (50%), ~34 MPa (75%), and ~39 MPa (100%). The non-monotonic trend shows a lubricant-to-load-bearing crossover with coverage. Controlling hydration therefore offers a practical knob to tune adhesion, friction, and energy dissipation in MXene laminates; we outline extensions to other terminations and note opportunities for nanoscale shear benchmarking.