One of the latest strategies for corrosion protection is the use of self-healing coatings, called self-healing coatings, which can repair the damaged surface of the substrate without human intervention . A self-healing outer coating can release an active healing agent when it breaks down and prevent spontaneous corrosion, which is of growing interest. The most interesting property of such coatings is hydrophobicity, which plays a fundamental role in corrosion protection.
Such oil coatings are inherently free of pinholes and can quickly self-heal many times when scratched, making them potentially useful as an emergency solution for protective barriers. The unusual thing is that the oil coating does not drip, it adheres very well and at the same time can heal quickly if it is scratched. Although in the electrochemical test shown in Fig. 5(m), only 3 consecutive “repair-repair” cycles have been shown, the oil coating is actually quite scratch resistant and can self-repair up to hundreds of times in the same place. Although the self-regeneration process took place during the first three days of salt spray exposure, the result was that the adhesion of the coating to the substrate after damage and the german protection of the substrate were maintained, resulting in a reduction of 65%. in the amount of creep corrosion observed after 1000 hours of exposure to ASTM B117 (Figure 2[b]).
For testing, the coating was fully cured and, as in plants that have been regenerated, this gradual return has already taken place, so the system will be more protected. When damaged, the system recognizes that the coating flows easily and reconnects to quickly repair the metal from scratches and cracks. Damage can be visible scratches, cracks or delaminations on the layer, or invisible corrosion between the metal and the coating. When scratched, coating components from nearby areas migrate into the damaged area and again protect the underlying alloy.
When the protective coating is damaged, the microencapsulated liquid healing agent is released from the broken microcapsules and polymerizes to repair the damaged area. Self-contained coating systems that automatically initiate healing when damaged; thus, damage triggers healing agents. healing agents The coating’s self-healing technology is based on AMI’s core-shell structure microcapsule and can be repaired when the coating is damaged. The self-healing capability of a nanocomposite coating is partly a result of the polymer coating morphology and can be used in other polymer systems for specific applications to provide self-healing capability.
These coatings can re-repair millimeter-scale scratches, apply easily to metal underwater, and protect metal from corrosion for extended periods of time. viscosity of silicone oil microcapsules, but it does not depend on materials. Due to their easy modifiability, due to which it is possible to obtain the desired useful properties, polymers and composites containing them are among the most used materials for obtaining self-healing coatings [2–16]. The ability of such coatings to repair local damage caused by climatic causes or mechanical damage is an important factor influencing their desirability. By using light microcapsules as thickeners, even low viscosity oils can form continuous and highly stable protective coatings on metal surfaces.
There is no report comparing coatings containing microcapsules encapsulated in various natural oils to evaluate which oil has the best anti-corrosion effect. Polymer vinyl ester coatings containing TiO 2 particles can be used to protect 5083 aluminum alloy from corrosion. The PANI/sol-gel coating provides aluminum alloy corrosion protection through a self-healing mechanism due to the ability of polyaniline to enter into a redox reaction.
High-viscosity fluids, such as lubricants, can form very stable coatings, but high-viscosity fluids, such as lubricants, do not flow easily to repair scratched areas. To protect metals from these unwanted scratches and cracks, Northwestern University researchers developed developed a self-healing oil-based coating. The main problem with one-shot coatings is that when damaged, the repair starts only at the surface, allowing corrosion under the layer, or only under the layer, preventing corrosion. On the substrate, but Weakens surface barriers, making them susceptible to corrosion.
This study shows that after scribe damage to the coating, the self-healing system built into the coating releases a repairing agent that forms a barrier at the damage site, resulting in a much greater reduction in scribe depth than the system does to the damage. Control (compare Figure 3 [a] and [b]). Overall, the results discussed herein demonstrate that self-healing additives can be used to improve the performance of coating systems that are prone to mechanical damage, microcracking and subsequent substrate corrosion in use.
Self-healing materials that perform in-situ self-healing at the microscopic level in response to macroscopic damage may be considered sustainable and durable materials that can be used in electronics, energy, transportation, and coatings applications. More advanced self-healing materials may follow, including self-healing gaskets and pipe liners.
While future work will further develop our understanding of the limitations and functionality offered by the inclusion of self-healing additives in marine protective coatings, what we have achieved so far suggests that coatings that provide this type of damage repair, can significantly reduce maintenance costs. service life and reduced downtime of resources. What is unclear is whether this same approach can be used for other types of coatings, but given that most coatings are based on polymers and that the research paper explicitly outlines the search for a way to make self-healing coatings of various types, I’d like to be cautiously optimistic.
Self-curing coatings are typically based on the microencapsulation approach pioneered by Dry et al.67 but optimized specifically for coating applications63,64. Hard polymer capsules have been used to incorporate inhibitors64, polymer monomers63 and linseed oil65 to provide the healing function of the coating. Protective coatings can also be obtained by deposition from a strongly negative polystyrenesulfonate (PSS) polyelectrolyte and a weakly positive polyethyleneimine (PEI) polyelectrolyte .