Corrosion inhibitor embedded spherical micro-pits fabricated using cetyltrimethyl ammonium bromide as etching template for self-healing corrosion protection

• A template chemical etching method for fabricating the spherical micro-pits.
• Etched spherical micro-pits as reservoirs used for inhibitor encapsulation.
• The inhibitor embedded spherical micro-pits confer self-healing property on system.
• The defects in system as a trigger induce the rapid release of embedded inhibitor.
• The released inhibitor restrains the corrosion of substrate for a longer time.

In this study, a self-healing system is composed of spherical micro-pits layer storing inhibitor and epoxy layer for physical shielding. The spherical micro-pits were fabricated in a copper substrate via HNO3 etching technique with the assistance of cetyltrimethyl ammonium bromide (CTAB) and ultrasonication. By means of localized electrochemical measurements, significant inhibition of corrosion activity can be observed in the scratched area. After being scratched, the self-healing system rapidly releases the inhibitor embedded in the spherical micro-pits to resist the corrosion process. The exposed copper is covered with an inhibitor adsorption film and protected effectively.