Facile room-temperature preparation of multifunctional superhydrophobic coatings based on basalt/TiO2 reinforced fluorocarbon varnish

Etching basalt scales boosts active sites and area, enhancing modification efficacy. • A micro-nano structure (EB/TiO₂) improves coating abrasion resistance effectively. • Excellent corrosion resistance results from a stable air layer during immersion. • Nano-TiO₂ can significantly improve the dispersion properties of basalt scales. Superhydrophobic coatings have increasingly demonstrated unique advantages in corrosion protection for marine engineering applications. However, their practical engineering implementation is often constrained by three key limitations: complex preparation processes, difficulties in large-scale application, and poor mechanical durability. Addressing these challenges, this study develops a multifunctional superhydrophobic coating suitable for room-temperature preparation and scalable application. Stable and cost-effective basalt scales serve as the microstructure foundation for robust superhydrophobic structures. Chemical etching is employed to activate the reactive sites on the basalt scale surfaces. By leveraging the silane bonding characteristics of 1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane, the construction of low surface energy treatment and the micro-nano hierarchical structures of basalt scales modified by nano-TiO 2 are accomplished in a single step. The resulting multifunctional superhydrophobic coating exhibits a water contact angle of 155.4°, retaining over 150° even after 60 friction cycles. In a 3.5 wt% NaCl solution, the impedance modulus at 0.01Hz (|Z| 0.01 Hz ) reaches which is six orders of magnitude higher than that of the bare substrate. Additionally, the coating demonstrates exceptional durability and self-cleaning properties. Notably, the entire preparation process is conducted at room temperature, significantly facilitating large-scale engineering applications, mass component processing, and commercial translation.