Super-hydrophobic materials have broad application prospects in industry, agriculture and daily life. Not only the types of the materials but also the structure and the morphology of their surface have a significant impact on the hydrophobicity of materials. In this study, nano-structured TiO2 coatings were deposited on glass surface by vacuum cold spray using agglomerated nano-TiO2 powder and aggregated nanostructured TiO2 powder to create nanostructured and micro-nano hierarchical structured TiO2 surface. The surface morphology of nanostructured TiO2 deposited surface was characterized by scanning electron microscopy and 3D laser microscopy. The influences of the surface morphology, annealing and fluoroalkylsilane adsorption treatment on the wettability of the surfaces were investigated. The results showed that the nanostructured TiO2 coatings in the as-sprayed and annealed states were hydrophilic. However, after adsorbing treatment by fluoroalkylsilane, the nanostructured TiO2 deposited glass surface exhibited super-hydrophobicity. The contact angle of water drops on TiO2 coating surfaces became greater than 120° up to 170° depending on the local surface morphology. Moreover, micro-nano hierarchical structured TiO2 coatings obtained by VCS using aggregated nano-TiO2 after fluoroalkylsilane adsorption exhibited excellent super-hydrophobic performance and the contact angle was greater than 170° and water droplets tended to roll on the surface with extremely low adhesion.

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