Tribological Performance of Sol-Gel Derived Superhydrophobic Film

A simple two-step process was developed in this study to render aluminum with lower friction and superhydrophobicity. Alumina film was firstly fabricated on aluminum by Sol-Gel technology. Fatty acid was then deposited on alumina film to endow superhydrophobicity. The surface morphology of alumina film after treatment using boiling water or hydrazine solution was evaluated. The effect of molecular structure of fatty acid on the wettability of the composite film was investigated. Friction-reducing behavior of the superhydrophobic films on aluminum was determined in a ball-on-plate configuration. It was found that the stearic acid film on alumina film treated by hydrazine solution showed superhydrophobicity and low friction, leading to significantly extending lifespan of the alumina film.