| Mother nature is always teaching us a lot. For instance, when the water droplet falls onto the surface of lotus leaf, it is able to remain the shape of sphere instead of spreading out, the dust can even be washed away by water to realize "self-cleaning effect", which is the representative figure of superhydrophobic surface. Across the sea polluted by crude oil, the seafowl cannot survive on account of the contaminated feathers, while fish can always manage alone owing to their oil droplet repelling ability of fish skin underwater. These superhydrophobic surfaces as well as superolophobic surfaces possessing particular infiltration properties attract more and more attention of researchers. They observe that due to the utilization of principles of bionics and by means of adopting micro and nanofabrication methods, we can composite rough structure similar to the surface of living substrate and can also construct surfaces with these properties on objects we needed. It is because the surface rough structure with proper surface energy are the critical factor to realize these particular wetting surfaces, which accord with Cassie-Wenzel theory well. Besides, these properties endow materials wider application space, such as self-cleaning, anti-corrosion, oil-water separation, delay-icing, anti-fogging and so on. Herein, we adopt one-step chemical method to prepare superhydrophobic inorganic engineering metal and alloy surface, underwater superoleophobic inorganic copper mesh which can be used in oil-water separation. And their relative performance is discussed throughly as following:In chapter 1, we firstly briefly introduced the wetting property and relevant concept, such as surface tension, contact angle, sliding angle, contacting angle hysteresis. Then we exhibited some typical wetting surface in nature by means of figure and word. The representative Wenzel, Cassie-Baxter wetting theory and the relationship between them were introduced specifically. Finally the preparation methods to construct different wetting substrates from different perspective were concluded.In chapter 2, we prepared superhydrophobic surfaces by one-step wet chemical method on metal aluminum and zinc simultaneously. The contacting angle (150°) and the sliding angle (it is less than 5°) make the surface possess self-cleaning ability. When the method is slightly improved, it can be applied to 8011 aluminum alloy. Apart from their excellent repelling property, their anti-corrosion, delaying-icing, superhydrophobic mechanism, reversible transformation, ultraviolet resistance property were all explored systematically.In chapter 3, an inorganic superhydrophilic-underwater superoleophobic membrane was fabricated on copper mesh by means of wet chemical one-step method. The mesh exhibited excellent underwater repelling oil ability with the oil contact angle of 159 for 1,2-dichloroethane. We also investigated the oil-water separation efficiency and relevant effect and found that 180# mesh could achieve 99.2% separation efficiency with the reaction time of 10s. The membrane remained stable in acid or alkaline solution, high water flux, strong intrusion pressure endurance and good stability under high temperature, all above broadened its practical application field. When suffered from green treatment, it could turn to superhydrophobic and then returned to the origin state with little fluctuation. The characteristic make the membrane we constructed show optimistic application prospect.In chapter 4, we reviewed and summarized the whole paper, meanwhile the potential prospect was illustrated as well. |
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