Synthesis and characterization of corrosion resistance and hydrophobic fluorine-based coating via sol–gel process

Hydrophobic and anticorrosion hybrid coating was synthesized via sol–gel process. For this purpose, coating was synthesized based on sol–gel precursors utilizing Tetraethylorthosilicate (TEOS), 3-glycidoxypropyl trimethoxysilane (GPTMS) and tetra (n-butyl orthotitanate) (TBT) and fluorine monomer (¹H, ¹H, ²H, ²H-Perfluoro octyltriethoxysilane, PFOTES) incorporated in obtained coatings. All prepared solutions were coated on iron plates by 120 μm by film applicator and then cured at room temperature. Hybrid network was characterized by X-ray diffraction spectroscopy, Atomic Force Microscopy(AFM), scanning electron microscope (SEM), energy-dispersive spectroscopy (EDS), and Fourier transform infrared (FTIR). Structural properties of obtained coatings indicated uniform distribution and dispersion with nano-sized inorganic particles (10–20 nm) and contact angle tests showed the oleophobicity of coatings increased by increasing the PFOTES which is related to lowering of surface energy by the presence of fluoropolymer. Anti-corrosion property of hybrid coating was checked based on polarization curves and EIS measurement and parametrically analyzed in an equivalent circuit when the coating was exposed to salt solution. Physical properties of coatings were measured by Taber test and pencil hardness test for scratch resistance. Hydrophobicity was measured as static water contact angle test. The corrosion resistance, Taber abrasion resistance and hydrophobicity increased significantly by increasing within the content of the fluorine chains.