Influence of Adding Functionalize Fluoroalkylsilanes (PFDTES) into a Novel Silica-Based Hybrid Coating on Corrosion Protection Performance on an Aluminium 2024-t3 Alloy

Silica-based coatings prepared by sol-gel polymerizing technology have been shown to exhibit excellent chemical stability combined with reducing the corrosion of metal substrates, showing promising use in aerospace and marine applications to protect light alloys. Moreover, this technology is an eco-friendly technique route for producing surface coatings, showing high potential for replacing toxic pre-treatment coatings of traditional conversation chromate coatings. This study aims to investigate the enhancement in corrosion protection of a hybrid-organic-inorganic silica-based coating cured at (80°C) by increasing the hydrophobicity to work on the aluminium 2024-T3 alloy. This approach involving a novel silica-based hybrid coating was prepared by introducing a 1H,1H,2H,2Hperfluorodecyltriethoxysilane (PFDTES) into the base hybrid formula created from tetraethylorthosilicatesilane (TEOS) and triethoxymethylsilane (MTMS) precursors; this formula was enhanced by introducing Polydimethylsiloxane polymer (PDMS). The corrosion protection properties of these coatings were examined by immersed in 3.5% NaCl with electrochemical impedance testing (EIS) and Potentiodynamic polarization scanning (PDPS). The chemical elements confirmation was done by infrared spectroscopy (ATR-FTIR); all this was supported by analyzing the surface morphology before and after the immersion by using scanning electron microscopy (SEM). The results of Electrochemical impedance testing analyses reveal the new open finite-length diffusion circuit element due to electrolyte media diffusion preventive by fluorinated groups. Also, it shows increases in corrosion protection arising from the increasing the hydrophobicity of the fluorinated coating compared to other formulas cured under similar conditions and bare Substrate. Additionally, the modified sol-gel exhibited improved resistance to cracking, while the increased hydrophobicity may also promote self-cleaning.