A waterborne coating for robust superamphiphobic surfaces

s Although recent progress has been made in the development of superamphiphobic fabrics, durability has been an obstacle to their wide application in practice. In this work, a robust water-borne superamphiphobic coating was successfully prepared using poly(vinylidene fluoride) (PVDF) latex particles (225 nm) modified with a cationic fluorocarbon surfactant (Zonyl 321) and an fluoroalkylsilane (FAS). It is demonstrated that the superamphiphobic coating could strongly adhere to various substrates (fabric, sponge, wood, and filter paper) to efficiently repel water and hexadecane under harsh environments such as strong ultraviolet (UV) irradiation, abrasion, plasma cleaning, boiling water, and strong acid/base corrosion. Furthermore, this coating could exhibit good thermal healing capability upon thermal annealing. Through a thorough study of the self-assembly structure of the composite PVDF/Zonyl 321/FAS particles, the robust superamphiphobic property was considered to relate to the following reasons. First, PVDF latex particles provided nanoscale roughness and good UV/chemical resistance. Second, cationic Zonyl 321 self-assembled onto negatively charged PVDF latex particles to form a shell structure with inner fluoroalkyl groups protected by the outer positive charges, which could provide strong adhesion to various fabrics. Third, FAS self-assembled into the fluoroalkyl shell and subsequent self-condensed to render a lightly crosslinked structure. After forming a dense coating onto a substrate, further crosslinking via self-condensation of FAS provided robustness for the coating. Subsequent thermal annealing at 130 °C drove the fluoroalkyl side chains to accumulate at the top surface for superamphiphobicity. This understanding of the composite PVDF/Zonyl 321/FAS system will help us design even better superamphiphobic coatings in the future.