Polyvinylidene Difluoride-SiO2-Silane Based Superhydrophobic Coatings on Carbon Steel with Enhanced Corrosion Resistance and Self-Cleaning Property

A novel PVDF-SiO2-Silane-based superhydrophobic (SHP) coating was fabricated on carbon steel samples with enhanced corrosion resistance and self-cleaning properties. The coating was fabricated by incorporating hydrophobic SiO2 nanoparticles into the PVDF matrix first and then coating with a silane based low surface energy material. Perfluoro octyl triethoxy silane (PFOTES) and hexadecyl trimethoxy silane (HDTMS) were the low surface energy materials used. Field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), energy dispersive x-ray spectroscopy (EDS), attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy and x ray photoelectron spectroscopy (XPS) characterization of the coatings revealed the formation of micro-nano hierarchical structures and also the presence of Si, O, F, and C in the coating. SHP carbon steel samples showed water contact angles (WCA) > 170 degrees and sliding angle similar to 0 degrees. The SHP property was unaffected after immersion in water and showed good chemical repellence to acidic and basic solutions. The prepared SHP samples showed excellent self-cleaning property. Electrochemical impedance spectroscopy (EIS) studies showed that the charge transfer resistance (R-ct) of SHP samples was almost 10 times more than that of bare samples in aggressive chloride conditions. [GRAPHICS] .