**7. Conclusions and Future Outlook**

The importance of physico-chemical properties of the emerging corrosion inhibitors based on IL and graphene for corrosion prevention of metallic substrates were outlined. Despite the very interesting properties of ILs and graphene for corrosion inhibition, there have been very few reports on their application for corrosion protection of metals. On the other hand, in spite of the considerable progress made in the chemistry of inhibitors, the inhibition study in a corrosion system presents the same challenges today as it did in the past. The transport of the corrosion inhibitor from bulk solution to the surface of the metal and the active inhibitor species that is available to interact with the metal are the fundamental factors governing corrosion inhibition. In the case of inhibitors that adsorb on the metal surface and inhibit the corrosion, there are two main challenges: (1) metal-inhibitor interactions and (2) transport of the corrosion inhibitor from bulk solution to the surface of the metal. These challenges could be overcome through immobilization of corrosion inhibitors into micro-/nanocontainers.

Although active corrosion inhibitors lead to sufficient temporary protection of the underlying metal, in the case of local damage of the protective coating, to reach an even more extended lifetime protection or to have repeatable healing at a specific location, an additional functionality of damage closure is required. Therefore, there is a significant need to develop the new micro-/nanocapsules family which are sensitive to pH, temperature, environmental conditions changes and dispersion of them to coatings should be considered.

Further research should also be focused on using more advanced characterization techniques and more fundamental studies in order to further clarify the mechanism of corrosion inhibitors and investigate the correlation between the structure and observed corrosion inhibition. This understanding will help us to tailor the inhibitor structure to obtain required corrosion inhibition properties. This would be more pronounced in the case of appropriate chemical modifications, especially by using eco-friendly inhibitors, which can render the coating with enhanced anticorrosive characteristics.

**Acknowledgments:** The authors gratefully acknowledge the financial support of the Australian Research Council's Linkage grant for carrying out this work and also the industry partner Wave rider Energy for financial support of this work.

**Author Contributions:** Namita Roy Choudhury, Mona Taghavikish and Naba Kumar Dutta designed the structure of the review. Mona Taghavikish wrote the review with Namita Roy Choudhury, Naba Kumar Dutta and the manuscript was finalized through contributions of all authors. All authors have given approval to the final version of the manuscript.

**Conflicts of Interest:** The authors declare no conflict of interest.
