Novel superhydrophobic core-shell fibers/epoxy coatings with self-healing anti-corrosion properties in both acidic and alkaline environments

In this study, a self-healing coating with inherent properties of superhydrophobicity and pH-responsibility is introduced through encapsulation of oleic acid and epoxy resin in cellulose acetate nanofibers by electrospinning method, followed by applying a layer of epoxy coating modified with both polydimethylsiloxane and SiO2 nanoparticles. The prepared core-shell fibers/epoxy coating has a static contact angle of 157.3 +/- 3 degrees with sliding angle of 3.5 +/- 0.5 degrees, while the electrochemical impedance spectroscopy results demonstrate that the self-healing rate of the scratched core-shell fibers/epoxy coating is 55.65 and 87.10 k omega cm2 d-1 after 4 and 12 days soaking in the 3.5 wt% NaCl solution with pH = 12.0 and 4.0, respectively. According to the results of the electro-chemical impedance spectroscopy, the corrosion resistance of the core-shell fibers/epoxy coating is remarkably more than the coating without fibers, and the coating with fibers exhibits a significant self-healing performance, excellent wear resistance, and chemical stability. This study would extend the application of the electrospinning technology in the field of superhydrophobic anti-corrosive coatings.