Smart epoxy coating modified with isophorone diisocyanate microcapsules and cerium organophosphate for multilevel corrosion protection of carbon steel

Enhanced Corrosion Resistance of Carbon Steel in Hydrochloric Acid Solution by Polyoxometalate-Estertin Derivatives

“…For instance, ionic liquids (ILs) have shown their outstanding performance in corrosion inhibition of steels in the acidic environment owing to many attractive characteristics such as high stability, high solubility, and low environmental hazards, although they suffer from the high production cost sometimes. , Moreover, plant extract corrosion inhibitors have been widely studied as green corrosion inhibitors owing to their high inhibition efficiency, chemical stability, and environmental friendliness. However, their application is limited by the difficulty of separation. − In recent years, intelligent corrosion inhibitors with pH responsivity, self-assembly, and self-healing properties have attracted more and more attention of scientists. − Despite the above achievements, the development of new sustainable, environmentally friendly, and highly efficient corrosion inhibitors in acidic media is still an important topic in metal protection.…”

Multilevel Self-Healing Characteristics of Smart Polymeric Composite Coatings

“…Moreover, at a high-frequency range, the Bode and phase angle plots of SLPC (Figure 10A,B) showed a capacitive attitude that exhibits small changes with immersion times, reflecting the high stability and minimum mass transfer, which proves the decent corrosion impeding properties of these coatings over the immersion period. 73 The evaluation results showed that the presence of inhibitor-loaded HNTs in SLPC can suppress the corrosion process at the steel surface for a certain period because of the physical adsorption of the corrosion inhibitor at the scratched zone.…”

Corrosion‐Responsive Self‐Healing Coatings

“…The release of MBT in PANI microparticles was hence enhanced in alkaline conditions to the higher solubility of MBT at higher pH values. [119] Besides, the release of corrosion inhibitors was enabled by dissolving of organophosphate [105] and mesoporous silica nanoparticles (see Figure 8c) in alkaline conditions. [101]…”

“…Corrosion inhibitors can form protective passive layers at corroded parts of the coating via several mechanisms (Figure 10): i) precipitation of protective oxide/hydroxide or other inorganic layers, such as phosphates, that are formed or promoted by inorganic corrosion inhibitors; ii) chelation between corrosion inhibitors and metal ions; iii) physi-or chemisorption of corrosion inhibitors on metal surfaces. For the first working mechanism, for instance cerium [86][87][88]105,114,117,118,168] and chromium-based [169] corrosion inhibitors provide self-healing via the mechanism that these cerium or chromium ions, migrate to corroding metal sites and react-usually as oxidizing reactants-to yield protective layers of cerium or chromium oxide/hydroxide. Another example is the self-healing of silk coatings which was attributed to precipitation of ions and compounds located in different layers.…”

“…Another possibility is that protective layers can be produced by reactions of a self‐healing agent and water at corroded sites. For instance, isophorone diisocyanate (IPDI) healing agent was released from microcapsules embedded in epoxy [ 105 ] and acrylic [ 93 ] coatings, and then reacted with water to produce isophorone‐diamine. The obtained isophorone diamine reacted with remaining IPDI to yield protective polyurea layers.…”