“…In the case of seawater, volatile corrosion inhibitors that trap molecules or ions in the medium to prevent their contact with the metal substrate are of interest. Examples of these organic inhibitors that can also be found in the literature are turmeric, L-cysteine or methylene blue, among others [ 36 , 37 , 38 ]. Some of the organic corrosion inhibitors can, in some cases, offer a double functionality: an efficient response to corrosion phenomena, thanks to the free radicals in their structure, such as turmeric, dimethyl yellow, chlorophenol red or crystal violet with antioxidant power, and the visual perception of pH changes that can identify corrosion processes as they occur, acting as optical sensors.…”