Corrosion assessment of Ag/Strearic acid-modified Copper Foams in aqueous environments: An Electrochemical Impedance study

This study investigates the corrosion resistance of superhydrophobic copper foams, specifically designed for water-oil separation in marine environments. A comprehensive electrochemical analysis was conducted to evaluate the corrosion behavior of superhydrophobic foams fabricated using a two-step immersion process in silver nitrate (AgNO 3 ) and stearic acid solutions. Electrochemical impedance spectroscopy (EIS) provided insights into the foams' corrosion resistance in distilled water and 3.5% NaCl solution over immersion periods of up to 120 hours. The results demonstrated that the coatings effectively reduced total impedance values, significantly improving the durability of the foams in simulated marine conditions. Additionally, morphological changes in the coatings were examined using scanning electron microscopy (SEM) to assess surface integrity over time. Contact angle measurements were performed to monitor the hydrophobicity of the coatings, as maintaining water repellency is crucial for long-term performance. To further understand the corrosion mechanisms and protective efficiency of the coatings, the experimental electrochemical data were analyzed using equivalent electrochemical circuits. Overall, this study highlights the potential of superhydrophobic copper foams as highly durable and efficient materials for applications in harsh marine environments, offering strong corrosion resistance and stability under prolonged exposure to marine conditions. • Superhydrophobic coatings boost corrosion resistance of copper foams in seawater. • Spectroscopy confirms stearate layers and oxides forming on modified foams. • Coated foams retain contact angles >150° after 120 h in water and NaCl. • EIS and circuit modeling show lasting barrier performance under harsh conditions.