Preparation of transparent superamphiphobic coating by rationally designed rough structure

Superamphiphobic coating with excellent optical transmittance has immense potential for utilization in many fields. However, it is challenging to maintain superamphiphobic surface with high transparency. Herein, a lotus leaf-inspired double-layered coating is proposed. The bottom layer of the coating consisted of fluorosilane-modified epoxy resin, while the top layer was composed of fluorosilane-modified SiO 2 and cellulose nanofibers (CNFs). The trends of optical transmittance and oil-water contact angle of the coating at different mass ratios between SiO 2 and CNFs were systematically investigated, and the stability of the coating was further studied by means of immersion in water, tape peeling, falling sand abrasion, and ultraviolet radiation. Experimental results showed that the coating exhibited the best comprehensive performance when the mass ratio of SiO 2 to CNFs was 1:1. The coating exhibited optical transmittance of 79%, while the contact angles of water, glycerol, glycol, and hexadecane were up to 169°, 163.5°, 155.2°, and 125.4°, respectively. Even after the stability test, the coating still showed a good superamphiphobic performance. This demonstrates that the coating exhibited excellent optical transmittance, good chemical stabilities, and high mechanical stability. Graphical abstract