Facile synthesis of fluorine-free, hydrophobic, and highly transparent coatings for self-cleaning applications


Non-fluorinated coatings have recently emerged as a new approach to avoid contamination on transparent surfaces. This research work concerns the synthesis of highly transparent, hydrophobic, durable, and self-cleaning coatings as an alternative to fluorine-based coatings used on glass. The developed coating is produced by a chemical route (sol–gel method) using two silica-based precursors, hexamethyldisilazane, and tetraethoxysilane (HMDS/TEOS). Then, the prepared Gel HMDS/TEOS was deposited on glass slides by the dip-coating technique. Afterward, the effects of mechanical durability, water-drop testing, thermal cycling testing, and aging times on the hydrophobicity of the gel were analyzed. The properties of the coating were characterized by optical microscopy, scanning electron microscopy, UV–VIS-NIR spectrophotometry, and contact angle measurement. The results show that the organic modification of the gel by trimethylsilyl (–Si–(CH3)3) groups leads to a homogeneous and a hydrophobic surface. Sufficient dilution of this gel with ethanol has been found to provide a highly transparent coating without losing its hydrophobic property. In addition, the robust and durable coating exhibits high self-cleaning performance suitable for various industrial applications.

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We acknowledge financial support from the Société Nationale des Chemins de Fer Français (SNCF) as a part of SURFNET project, set up by the Institut de Recherche Technologique (IRT) RAILENIUM. We also thank the Laboratoire des Matériaux Céramiques et Procédés Associés (LMCPA) and the Université Polytechnique Hauts-de-France (UPHF) for their collaboration.

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Correspondence to Abderrahmane Hamdi.

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Hamdi, A., Chalon, J., Laurent, P. et al. Facile synthesis of fluorine-free, hydrophobic, and highly transparent coatings for self-cleaning applications. J Coat Technol Res (2021). https://doi.org/10.1007/s11998-020-00444-y

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  • Non-fluorinated coatings
  • Transparent surfaces
  • Hydrophobicity
  • Self-cleaning