Hydrophobic coatings were fabricated without any

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hydrophobic coatings were fabricated without any further surface modifications, showing water contact angles of up to 160 ° [ 100 ]. Introduction of particles increases surface roughness of hybrid coatings. Uniform TiO 2 nanoparticles and fluoroalkylsiane (FAS-13) are introduced into the hybrid coatings to enhance hydrophobic property of the surface. TiO 2 nanoparticles increase surface roughness. The contact angle with water is 150 ± 1 ° . The super-hydrophobic coatings exhibit an excellent corrosion resistance in chlo- ride containing solution at the room temperature [ 101 ]. Micro-nanoscale binary structured composite particles of silica/fluoropolymer are prepared using an emulsion-med- iated sol–gel process, and then these composite particles are applied to various substrates. Rough coating surfaces on which water contact angles are larger than 150 ° are attained [ 102 ]. A biomimetic super-hydrophobic surface is composed of FAS-modified LBL structured film-coated electrospun nanofibrous membranes. The rough fiber surface caused by the electrostatic LBL coating of TiO 2 nanoparticles and poly(acrylic acid) (PAA) is used to imitate the rough sur- face of nanosized grooves along the silver ragwort leaf fiber axis. A (TiO 2 /PAA) 10 film-coated cellulose acetate nanofibrous membrane with FAS surface modification showed the highest water contact angle of 162 ° [ 103 ]. Preparation of super-hydrophobic coating has been dis- cussed. Sometimes we want to change hydrophobic char- acter of coating surfaces. How does hybrid coating surface change from super-hydrophobic to super-hydrophilic? UV/ozone treatments are used to control the surface coverage of hydrophobic organic ligands on the silica framework, allowing the contact angle with water to be continuously varied over the range of 160 ° to \ 10 ° [ 91 ]. A super-hydrophobic surface, of which contact angle is 151 ° , is obtained by modifying a SiO 2 microparticle film- coated glass plate with octadecyltriethoxysilane (ODS). The super-hydrophobic surface is converted to super- hydrophilic by remote oxidation using a TiO 2 photocatalyst for 40 min, due to oxidative decomposition of the ODS monolayer. The increase in the wet-ability of the super- hydrophobic surface with water is faster than that of a normal hydrophobic surface [ 104 ]. However, we can infer that the methods of changing from super-hydrophobic surface to super-hydrophilic also damage super-hydro- phobic coatings. Although super-hydrophobic hybrid coatings provide excellent corrosion protection for metals, the super- hydrophobic properties of man-made films fade away with light, scrub or environmental contamination slowly due to decomposition of special microsurface roughness, accu- mulation of pollutants or degradation of hydrophobic functionalities. The durable property of the present super- hydrophobic hybrid coatings is not enough for industrial application and needs to be improved [ 105 ]. The fouling behavior of superhydrophobic coatings with nanoscale interfacial roughness has been investigated. Super-hydro-
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