Environmentally Friendly Photoluminescent Coatings for Corrosion Sensing

Although an increasing number of studies are being devoted to the field of corrosion, with topics from protection to sensing strategies, there is still a lack of research based on environmentally eco-friendly materials, which is essential in the transition to sustainable technologies. Herein, environmentally friendly composites, based on photoluminescent salts dispersed in vegetable oil-based resins, are prepared and investigated as corrosion sensing coatings. Two salts NaA, where A- is a lanthanide complex anion (with Ln = Nd³⁺, and Yb³⁺), are incorporated into the resins as active functional fillers and different coatings are prepared on carbon steel substrates to assess their functional properties. The influence exerted by a corrosive saline solution on the morphology, structural, and photoluminescent properties of the coatings is evaluated, and their suitability for the practical detection of the early corrosion of coated carbon steel is demonstrated. The photoluminescence of the composite coatings depends on the corrosion time, with the effect being more important for the coatings doped with Nd³⁺. The present work shows that the composites obtained are suitable candidates for corrosion sensing coating applications, offering improved sustainability.