Plant cuticle-inspired “skeleton-skin” strategy: Engineering robust and superhydrophobic wood composites via in-situ molecular assembly

In nature, the plant cuticle serves as a sophisticated organic barrier, where a rigid polysaccharide framework is integrated with self-assembled epicuticular waxes to resist environmental stressors. Inspired by this evolutionary paradigm, we propose a “skeleton-skin” dual-reinforced strategy to fabricate a robust, superhydrophobic, and antibacterial wood composite (SPAFD). A rigid internal “Skeleton” was constructed by selectively removing lignin and conducting in-situ ring-opening polymerization of polylactic acid within the cellulose scaffold, achieving a 746% increase in compressive strength. Simultaneously, a durable external “skin” was engineered through the synergistic interfacial assembly of arachidic acid and 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane, mimicking the hierarchical protection of plant waxes. Supported by density functional theory calculations, this integration overcome interfacial kinetic barriers to reach a deep thermodynamic basin, while establishing a localized low-energy electrostatic shield that masks substrate polarity. Consequently, the SPAFD composite achieves stable superhydrophobicity (water contact angle > 154°) and maintains its non-wetting integrity under severe mechanical abrasion, chemical corrosion, and long-term hydrothermal aging (80 °C, 80% RH for 56 days). Additionally, a dual “passive-active” antibacterial mechanism was achieved, combining physical anti-adhesion with chemical sterilization via slow-release lactic acid. This work provides a theoretically guided approach for transforming wood into high-performance structural materials for rigorous outdoor applications. Graphical