Silica-based superhydrophobic coating for wood panel: a review of recent advances and future perspectives

Superhydrophobic silica-based coatings have attracted significant attention for protective applications due to their exceptional water repellency, self-cleaning capability, and multifunctional potential. However, translating laboratory-scale performance into real-world applications remains challenging, primarily due to the limited durability under mechanical, chemical, environmental, and biological stresses. This review critically summarizes recent advances (2018–2025) in the design, fabrication, and long-term performance of silica-based superhydrophobic coatings, with particular emphasis on surface functionalization strategies, hierarchical micro/nano architectures, interfacial adhesion mechanisms, and realistic durability evaluations. The roles of sol–gel processing, silanization, polymer and bio-adhesive binders, and nanohybrid systems in enhancing mechanical robustness, corrosion resistance, UV stability, and biological durability, especially for wood protection, are systematically discussed. Furthermore, applications across various substrates, including wood, metals, glass, and transparent materials, are reviewed to highlight structure-property performance relationships. Finally, current limitations, research gaps, and future perspectives toward durable, environmentally benign, and application-ready superhydrophobic silica coatings are outlined. This review provides a comprehensive framework for the rational design of next-generation superhydrophobic coatings suitable for harsh service environments.