Reversible Molecular Exoskeleton for On-Demand Decoupling of Environmental Stability and Interfacial Reactivity in...

The practical commercialization of two-dimensional transition-metal carbides (Ti3C2Tx MXenes) faces a fundamental paradox: while environmental isolation is necessary to prevent thermodynamically induced oxidative degradation, conventional permanent polymer encapsulation inevitably sacrifices intrinsic interfacial reactivity and charge transport. Herein, a switchable interfacial engineering strategy is developed to construct a reversible molecular exoskeleton using a pH-responsive L100/EPH polymer matrix, thereby effectively decoupling long-term environmental durability from on-demand physicochemical functionality. This matrix establishes a dense dynamic hydrogen-bonded network that not only serves as a stringent kinetic barrier to oxidative permeation but also structurally pins the MXene nanosheets to suppress inter-lamellar slippage, thereby reinforcing mechanical toughness and suppressing structural creep. Consequently, the protected composite film exhibits extraordinary structural endurance under severe industrial conditions, while achieving an enhanced electromagnetic interference shielding effectiveness of 68.66 dB, driven by intensified interfacial polarization. Crucially, this sacrificial exoskeleton can be rapidly and quantitatively dissociated via mild alkaline activation, thereby seamlessly reactivating the MXene film and restoring its non-destructive intrinsic conductivity (6748 S cm-1) and hydrophilicity. This reversible dynamic interface strategy provides a highly scalable and robust pathway for the long-term storage, transport, and on-demand device integration of highly reactive 2D materials.