Protective Organic Coatings with Anticorrosive and Other Feedback-Active Features: Micro- and Nanocontainers-Based Approach

Abstract

Development of materials possessing the ability to recover their main function(s) in response to destructive impacts is, today, one of most rapidly growing fields in material science. In particular, protective organic coatings with the features to heal or restore their protective function autonomously are of great interest in fighting surface deterioration processes like corrosion, biofouling, and other affecting metallic structures. Embedding of micro- and nanocontainers in protective coatings is a frequently used technique nowadays to provide them one or several feedback-active functionalities. Depending on the container's morphology and active agent(s) filled, coatings with specifically aimed self-recovering functionalities (anticorrosive, water-repelling, antifouling, etc.) or multifunctional coatings can be created. In the present paper, different types of containers for self-recovering functional coatings synthesized by use of mesoporous nano- and microparticles or on the emulsion basis are presented. L-b-L polyelectrolyte deposition, interfacial polymerization, surface precipitation, Pickering emulsions, and in situ emulsion polymerization were utilized for the preparation of nano- or micro-scaled containers. Morphology of containers, efficiency of encapsulation, and kinetics of active agents release were investigated using modern techniques such as transmission mode in the scanning electron microscopy (T-SEM), cryo scanning electron microscopy (Cryo-SEM), etc. Incorporation of containers in the coating matrix was followed by the experimental modeling of external impacts, leading to simultaneous container damage. Subsequent release of the active agent at the affected site caused the active feedback of the coating and self-recovery of its specific protective function. The advantages of novel container-based protective coatings as compared to conventional ones are illustrated by corrosion tests results according to ASTM Standard B117.