# Advanced Micro/Nanocapsules for Self-Healing Coatings
## 2 Self-Healing Coatings Based on Additives Including Corrosion Inhibitors
The fabricated protective film prevented the aggressiveness of Cl\({}^{-}\) in the solution, resulting in the existence of exceptional corrosion inhibition efficiency for the modified coating with the aforementioned loaded microcapsules. In the study of [PERSON] and his team, an intelligent coating for mild steel corrosion protection was developed [23]. Free radical polymerization was used for the synthesis of a hybrid hydrogel based on benzotriazole, polyethyleneimine, hydroxypropyl acrylate, and vinyltriethoxysilane. The prepared hydrogel was used in the fabrication of an intelligent coating that was applied to mild steel. Electrochemical characterizations were conducted for the corrosion protection assessment of the intelligent coating. The obtained results showed that the increase in the hydrogel in the coatings resulted in an improvement of the anti-corrosion capability of the coatings. The corresponding mechanism relied on the formation of an inhibitor-adsorptive layer onto the mild steel due to the release of benzotriazole. In order to promote the application of dissimilar material blisks for advanced aero-engines built from Ti17 (\(\alpha\)+\(\beta\)) and Ti17(\(\beta\)) alloys developed via linear friction welding (LFW), a thorough investigation was conducted on the failure mechanisms and performance enhancements of these joints. Using methods including in situ tensile testing with scanning electron microscopy and quasi in situ electron back-scattering diffraction combined with transmission electron microscopy for high-cycle fatigue analysis, the study concentrated on microstructural changes, including phase transformations and dynamic recrystallization. Microstructural changes during welding were determined via \(\alpha\) dissolution and continuous dynamic recrystallization (CDRX) of the \(\beta\)-phase. According to the research findings, microcracks at \(\alpha\)/metastable \(\beta\) borders on the Ti17 (\(\alpha\)+\(\beta\)) side were linked to high-cycle fatigue failure, whereas tensile failure was associated with dislocation slip concentration in the thermomechanically impacted zone [24]. The integration of micro- and nanocontainers into self-healing coatings significantly enhances their functional applications in material science. Microscale containers, typically ranging from 50 to 200 \(\mu\)m, are designed to easily rupture under mechanical stress, thereby releasing healing agents stored within them, which is crucial for the efficient repair of damaged areas. This intelligent release mechanism is not solely dependent on mechanical stress; it can also be finely tuned to respond to various environmental stimuli, such as changes in pH or temperature, ensuring active agents are discharged only when necessary. The responsiveness of these containers to external stimuli facilitates the smart release of agents, improving the self-healing capabilities and corrosion protection of advanced coatings. Nanocontainers, due to their smaller size, are particularly effective for carrying corrosion inhibitors, allowing a more efficient delivery of active agents and enhancing the protective qualities of the coatings. The release of active agents from these containers through capillary action when cracks form aids in restoring the coating's barrier properties. This combination of intelligent design and responsive behavior underscores the transformative potential of micro/nanocontainers in the development of advanced self-healing materials, marking a significant advancement in modern material science and technology [25]. The development, characterization, and validation of self-healing coatings, including corrosion inhibitors, is an active area of research that pays attention to enhancing the economic viability, environmental friendliness, and effectiveness of these advanced materials.