The dependence of drop evaporation rate and wettability on corrosion kinetics

Abstract

The effect of corrosion of aluminum alloy on the droplets evaporation kinetics both for superhydrophilic and superhydrophobic surfaces is studied experimentally. The characteristic stages of the drop diameter changes due to corrosion correlate with the evaporation stages. Corrosion controls the drop wettability and the evaporation rate. At high rates of corrosion and with intense gas release, the evaporation rate is shown to decrease due to a reduction in the rate of heat supply to the droplet surface. The performed analysis of limiting factors illustrates that evaluating only electrochemical factors is not sufficient. Modeling the corrosion kinetics also requires taking into account the statistical nature of the corrosion process, which depends on the wettability and diameter of the drop. It has been for the first time demonstrated that the corrosion kinetics is determined by the modes of wetting. Expressions relating the corrosive current to the modes for the contact line of the drop are presented. Pre-temperature annealing of the material leads to an increase in the rate of corrosion and the appearance of large pits.