Self-Healing Anticorrosion Polyelectrolyte Multilayer Using Smart Nanocontainer

High-value materials in, for example, the automotive, railroad, and aerospace industries require the multifunctional coatings for improved performance, self-healing, and durability. It is especially urgent to find new routes for the next generation protective coating, especially taking into consideration the banning of carcinogenic Cr(VI) ions. In this respect, the protective coating should provide the specific functionalities in response to the external stimulus. Here, we introduce the polyelectrolytes, branched poly(ethyleneimine) (BPEI) and poly(acrylic acid) (PAA), to build the multilayer structures. Polyelectrolyte nanocontainers with controlled release properties can be used to fabricate a new family of active coatings, with quick response to the changes of coating environment or coating integrity. The release of anticorrosion agent, 8-hydroxyquinoline (8-HQ), encapsulated into the polyelectrolyte nanocontainer can be triggered by pH, salt, or surfactant with a narrow window, and thus preventing spontaneous leakage of the agent. The coating can also have several active functionalities when several types of agent or several kinds of nanocontainers are loaded as the sandwich structures in order to achieve staged release with the corresponding active agent incorporated into a coating matrix