Influence of adhesives on the construction of a robust superamphiphobic surface

Abstract A hierarchical structure is a prerequisite for spray-coating of a superamphiphobic surface because of its capability to enhance surface roughness, and retain large numbers of fine air-pockets. However, utilization of adhesives always compromises the performance of the super-repellent coating. Therefore, it is of great significance and extremely challenging to fabricate a superamphiphobic surface. In the present work, a commercial inorganic adhesive aluminum dihydrogen phosphate (ADP) was applied to a hierarchically mesoporous TiO2 suspension to fabricate superamphiphobic coating. N2 adsorption-desorption isotherms were used to characterize the air-pockets inside the coating and to correlate the wettability of the coating with varied ADP contents. The results indicated that with the increase of ADP, it covered TiO2 building blocks and filled the space, which destroyed the hierarchical structure, resulting in a change from Cassie to Wenzel state. When the addition amount of ADP was less than 8%, superamphiphobic surface with excellent mechanical robustness could be achieved.