Durability Research Of Superhydrophobic Surfaces Prepared On Aluminum Substrate And Modified By PTES

Wetting is one of the most common phenomena in nature,in recent decades,researchers have paid a lot of attention to these phenomena and created a series of bio-science technologies.Lotus leaf with superhydrophobility and self-cleaning is a typical representative of wetting phenomena,known as the "Lotus Effect".Inspired by this phenomenon,a variety of methods about preparing superhydrophobic surfaces have been developed whose contact angle is greater than 1500 and sliding angle is less than 100 as well as achieving abundant results in the study.However,some problems have to be solved for this technology to be applied in the industry,such as the mechanical stability,preparation costs,aging problem and so on.Because of the weak micro/nano structure of superhydrophobic surface,contaminants in the environment can stick easily into the rough structure,resulting in decline of the superhydrophobility.Therefore,it is worthy for us to discuss the stability and durability of superhydrophobic samples in different kinds of environment,which benefits the development and application of this bionic technology.In this paper,superhydrophobic surfaces on the aluminum modified by PTES were prepared,and a series of experiments were designed to verify if the surfaces still maintained the superhydrophobic property after they were treated in different environments for a long time.Moreover,the reasons for the loss of superhydrophobility were analyzed.Firstly,we analyzed the wettability,surface topography and surface composition of the original superhydrophobic surfaces.Then they were placed in the artificial seawater in the natural surroundings.The wettability were analyzed again after different time intervals of corrosion.Meanwhile,the icephobic durability of superhydrophobic surfaces upon two multiple de-icing(ice-breaking and ice-melting)processes was studied.When the samples were no longer superhydrophobic,their surface topography and surface composition were investigated to analyze the causes of the loss of superhydrophobility.The results showed that superhydrophobic surfaces had good stability and durability in the natural surroundings,and the decrease of the superhydrophobility was mainly due to the destruction of the micro/nano structure.Meanwhile,considering the significance of superhydrophobic surfaces in the oceanic metal anti-corrosion area,we designed experiments to study their stability under different pressures in the artificial seawater.In the experiments,the superhydrophobic surfaces were immersed in the artificial seawater with different liquid pressures to simulate different depths of seawater.We tested the wettability of the samples and analyzed the reasons for the loss of superhydrophobility through the surface topography and surface chemical composition characterization.The consequences showed that the superhydrophobic samples could withstand the pressure up to 0.2 MPa(equivalent to 20 m depth in the seawater),and the liquid pressure mainly destroyed the micro/nano structure and the "air cushion" to make the samples lose superhydrophobility.However,the "air cushion" could be partially recovered through drying.