The need to create new enhanced corrosion resistant coatings has grown because of the financial burden corrosion places on certain industries such as oil industry. Organic inhibitors have been extensively reported to protect metals and metallic alloys from corrosion although they have a negative impact on environment. Development of better corrosion resistant coatings such as metal alloys, metal-ceramics, polymers, and hydrophobic films are examples of corrosion resistant coatings for metals and alloys. Recently, superhydrophobic coatings have been widely implemented into many fields including anti-fogging transparent materials, self-cleaning surfaces, biomedical and corrosion applications. In the proposed chapter, a comprehensive review will be dedicated for the fundamentals and developments of superhydrophobic materials including theoretical background; superhydrophobicity in nature; preparation techniques; and recent attempts to develop superhydrophobic surfaces.
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Many researches have studied the role of superhydrophobicity on corrosion prevention (Ejenstam et al., 2013; Grignard et al., 2011; Jin, Li, Han, Wang, & Sun, 2014; Su & Yao, 2014; Zhou, Lu, Xin, & Liu, 2013). Learning from nature, a superhydrophobic surface can be produced by manufacturing an optimum surface roughness pursued by passivation with a low surface energy coating leading to a very low area of contact between the solid surface and the liquid, causing a water drop to roll off the surface. As the contact area of water on a superhydrophobic solid surface is omitted, such surfaces would effectively decrease the contact area of water. Therefore, the superhydrophobic film can resist corrosion and protect the metals. It is well known that, copper and its alloys have been one of the important materials in industry owing to its thermal and high electrical conductivities, mechanical workability and its comparatively noble properties. It is vastly utilized in various implementation in communications and electronic industries as a conductor in electrical power lines, pipelines for territorial and processing water utilities involving heat exchangers, heat conductors and seawater (Kim, 2008). Hence, corrosion of copper and its resistance in a wide variety of media, especially when they have chloride ions, have aggravated concern of a number of researchers (Barthlott & Neinhius, 1997; Bhushan, 2011b; Gennes, Wyart, & Quere, 2004). In addition to copper, aluminum and its alloy are also vastly utilized in marine, aerospace, and automotive applications due to their low density, convenient mechanical properties and comparatively good corrosion protection. Aluminum and its alloy possess a naturalistic corrosion resistance from its oxide layer, but it may be corroded if subject to aggressive environments (Traverso & Canepa, 2014). The appropriate coatings on copper, aluminum and their alloys may be reliable and add longer service life.