Dragonfly wing-inspired MXene-reinforced self-locking interpenetrating network coating with ultralow friction and corrosion resistance

Inspired by the rigid vein-flexible membrane hierarchical architecture of dragonfly wings with an exceptional natural system integrating strength, flexibility, and damage tolerance, we designed and fabricated, a robust, multifunctional composite coating (O-H-M) based on polysilazane (OPSZ), hydroxyl-terminated polybutadiene (HTPB), and MXene nanosheets for synergistic lubrication and corrosion protection. This bio-inspired design strategically integrates three complementary components: a rigid OPSZ backbone for structural support and substrate adhesion, flexible HTPB chains that enable energy dissipation via shear deformation and chain slippage, and 2D MXene nanosheets serving dual roles as a solid lubricant and nano-reinforcement. The “self-locking interpenetrating network” formed by chemical crosslinking between OPSZ and HTPB effectively mitigates the inherent brittleness of OPSZ, endowing the coating with remarkable toughness. MXene further enhances load-bearing capacity and wear resistance while constructing a labyrinth barrier against corrosive species. The resulting O-H-M coating achieves an ultralow friction coefficient (˂ 0.1) and a wear rate far reduced by one order of magnitude compared to pure OPSZ. It also exhibits outstanding long-term corrosion resistance, decreasing the corrosion current density of Q235B by three orders of magnitude relative to the bare metal substrate, and maintains robust stability under coupled tribocorrosion conditions. Molecular dynamics simulations reveal that the superior lubricity originates from synergistic effects: the cross-linked network facilitates molecular chain mobility and energy dissipation, while MXene enables interlayer sliding to reduce shear stress. This work offers practical and scalable paradigm for developing next-generation bio-inspired multifunctional coatings that balance mechanical robustness, lubricity, and chemical stability, with great potential for harsh engineering environments.