Ambient-temperature self-healing Superhydrophobic coatings: A fluorine-free green strategy for sustainable wood protection

Wood, a renewable and sustainable building material, suffers from poor durability in outdoor applications due to its hygroscopic nature. Current protective coatings often rely on energy-intensive processes or hazardous fluorinated chemicals, conflicting with the principles of green chemistry. Herein, we report a green strategy for fabricating self-healing superhydrophobic wood coatings that operate autonomously at room temperature. The coating is formed through a one-step co-condensation of octadecylamine (ODA) with methyltrimethoxysilane (MTMS) in ethanol, avoiding fluorinated compounds and external energy input for healing. The resulting surface exhibits a hierarchical micro/nano-structure, achieving an ultralow surface free energy (~6 mJ/m 2 ) and a water contact angle (WCA) exceeding 155°. After mechanical damage or severe plasma etching, superhydrophobicity is spontaneously restored within 36 h at ambient conditions. Notably, the MTMS/ODA coating demonstrates superior self-healing cyclability (43 cycles), exceptional UV stability (WCA > 140° after 936 h), and resistance to neutral/alkaline media. By significantly reducing water uptake and improving dimensional stability, this coating extends the service life of wood. This work presents a scalable, energy-efficient, and fluorine-free solution for protecting wood, aligning perfectly with the goals of sustainable construction and green materials engineering.