Facile Synthesis of Smart Nanocontainers as Key Components for Construction of Self-Healing Coating with Superhydrophobic Surfaces

SiO(2)-imidazoline nanocomposites (SiO(2)-IMI) owning high loading capacity of corrosion inhibitor, 1-hexadecyl-3-methylimidazolium bromide (HMID), and a special acid/alkali dual-stimuli-accelerated release property have been synthesized via a one-step modified Stöber method. SiO(2)-IMI were uniformly distributed into the hydrophobic SiO(2) sol to construct “host”-“guest” feedback active coating with a superhydrophobic surface (SiO(2)-IMI@SHSC) on aluminium alloy, AA2024, by dip-coating technique. SiO(2)-IMI as “guest” components have good compatibility with “host” sol-gel coating, and more importantly, once localized corrosion occurs on the surface of AA2024, SiO(2)-IMI can simultaneously respond to the increase in environmental pH around corrosive micro-cathodic regions and decrease in pH near micro-anodic regions, promptly releasing HMID to form a compact molecular film on the damaged surface, inhibiting corrosion spread and executing a self-healing function. The scanning vibrating electrode technique (SVET) was applied to illustrate the suppression process of cathodic/anodic corrosion activities. Furthermore, benefiting from the superhydrophobic surface, SiO(2)-IMI@SHSC remained its protective ability after immersion in 0.5 M NaCl solution for 35 days, which is far superior to the conventional sol-gel coating with the same coating thickness. The facile fabrication method of SiO(2)-IMI simplifies the construction procedure of SiO(2)-IMI@SHSC, which have great potential to replace non-environmental chromate conversion coatings for practical use. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s11671-016-1444-3) contains supplementary material, which is available to authorized users.