Abstract
The present work evaluated the structure and heterogeneities, surface chemistry, hydrophobicity level, and corrosion protection in a saline environment of electrodeposited sol-gel superhydrophobic coatings on carbon steel, using microscopy techniques, energy dispersive X-ray spectroscopy (EDX), water contact angle measurements, and electrochemical impedance spectroscopy (EIS). Furthermore, the effect of silane precursor concentration on the aforementioned response variables was tested. Regarding the structure, results point out rough deposits composed of two layers with different properties and thicknesses, and preferential deposition on the top area of the carbon steel coupon. Elemental mapping proved the chemical stability of the film in NaCl 3.5%wt., while increasing the amounts of silane precursor up to 40 mmol showed also increased results for water contact angle (157o), impedance modulus at 0.01 Hz (107 Ohm.cm2), and film thickness (70 µm). However, the addition of greater amounts resulted in miscibility issues in the hydrolysis solution.
Highlights
Superhydrophobic surfaces present the ability to repel polar liquids such as water so that the angle formed between the solid surface and the tangent of a water droplet is superior to 150o 1
Not explicitly designed to fabricate superhydrophobic surfaces, the electrodeposition of sol-gel coatings was first reported by Shacham et al.[11], resorting to the electrochemical generation of hydroxyl ions on conductive materials in order to control siloxane condensation reaction rates, sol stability, and, film deposition
It is worth noting that, even though the applied techniques cannot detect nanometric scales, its presence is expected due to the water contact angle values superior to 157o obtained by such film in previous work[15], in agreement with the CassieBaxter model[16]
Summary
Superhydrophobic surfaces present the ability to repel polar liquids such as water so that the angle formed between the solid surface and the tangent of a water droplet is superior to 150o 1. Such lack of affinity with water provides materials with important properties such as self-cleaning[2,3], anti-fogging[4,5], low friction in water[6,7], and coatings with improved barrier against water permeation, and, corrosion protection[8,9,10]. Wu et al.[12] developed electrodeposited coatings combining tetraethoxysilane (TEOS) and dodecyltrimethoxysilane (DTMS), a precursor with a long alkyl chain and responsible for the surface energy
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
