الفهرس 
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Abstract
Superhydrophobic coatings with water contact angle (WCA) greater than 150o have received great interest owing to their unique properties like water repellent, self cleaning, and corrosion resistance. The main objective of the present study is to produce superhydrophobic composite coatings using the spray technique to investigate the wettability and corrosion behavior of the coated materials for industrial applications. The literature review of this study discusses the superhydrophobic property in nature that humans try to mimic. Surface wetting conditions and their theories were studied. The techniques of fabrication of superhydrophobic surfaces were also discussed. Different applications of superhydrophobic surfaces were mentioned. Advantages of Polyvinylidene fluoride (PVDF) polymer used in this work were also stated. The PVDF was mixed with various concentrations of nanoparticles, and the mixture was sprayed onto steel, aluminum, and glass substrates. The wettability and morphology of the coated surfaces were investigated using the sessile droplet method and scanning electron microscopy (SEM), respectively. The corrosion resistance of bare substrates was compared to that of those coated with PVDF alone and those coated with PVDF/ nanoparticles using Tafel polarization techniques. The force of adhesion between the coat and the substrates was measured in pounds per square inch. A nano-indentation test was also used to measure the hardness of the coating layer. The results indicate that the PVDF containing 1.5 wt. % ZnO or 1.5 wt. % Al2O3 coated substrates showed a significantly higher water contact angle (> 150◦) and lower contact angle hysteresis (< 10◦). The PVDF containing 2 wt. % TiO2)-coated substrates showed a water contact angle more than 140◦ and lower water contact angle hysteresis (WCAH) (< 10◦), compared to the uncoated and PVDF-coated substrates. Moreover, corrosion test results showed that the superhydrophobic PVDF/ nanoparticles coatings had a much higher corrosion protection efficiency and iii polarization resistance for steel and aluminum than that of the uncoated and PVDF coated ones. The adhesion force between the coating layer and the substrates were shown to be moderately accepted for the coatings having the best WCA and WCAH values. The composite-coated substrates showed a significantly higher hardness and elastic modulus than those coated with PVDF alone.