Study of corrosion protection of mild steel by eco-friendly silane sol–gel coating

• Published in: Journal of sol-gel science and technology 2014-06, Vol.70 (3), p.329-338
• Main Authors: Asadi, N., Naderi, R., Saremi, M., Arman, S. Y., Fedel, M., Deflorian, F.
• Format: Article
• Language: English
• Subjects: Carbon steels; Ceramics; Chemistry; Chemistry and Materials Science; Coating; Colloidal gels. Colloidal sols; Colloidal state and disperse state; Composites; Contact angle; Corrosion prevention; Corrosion tests; Crosslinking; Electrochemical impedance spectroscopy; Electrochemistry; Electrode polarization; Exact sciences and technology; Field emission microscopy; General and physical chemistry; Glass; Immersion; Inorganic Chemistry; Low carbon steels; Materials Science; Nanotechnology; Natural Materials; Noise; Optical and Electronic Materials; Original Paper; Power spectral density; Protective; Protective coatings; Protective structures; Scanning electron microscopy; Silanes; Sol gel process; Sol-gel processes; Submerging; Substrates; Surface analysis (chemical); Tetraethyl orthosilicate; Variations
• ISSN: 0928-0707; 1573-4846
• DOI: 10.1007/s10971-014-3286-8

The effects of dipping duration in the silane solution and the sol pH on the protective performance of an eco-friendly silane sol–gel coating consisting a mixture of tetraethoxysilane, methyltriethoxysilane and glycidyloxypropyltrimethoxysilane applied on mild steel substrate were studied in this paper using electrochemical techniques and surface analysis. In consistency with the data obtained from electrochemical impedance spectroscopy and polarization curves, electrochemical current noise fluctuation analysis, appearance of the power spectral density plots and noise resistance indicated the most efficient sol pH and immersion time in the silane solution. In this regard, field emission type scanning electron microscopy images and water contact angle values revealed impact of the sol pH on the film structure. The enhancement in protective performance of the hybrid coating resulting from optimum immersion in the silane solution with appropriate pH was connected to the film homogeneity and higher cross linking and thickness as well. Moreover, a good trend correlation was observed between the noise resistance and low-frequency impedance modulus data.