Self-assembled graphene oxide microcapsules in Pickering emulsions for self-healing waterborne polyurethane coatings

A self-assembly process was employed to prepare the graphene oxide microcapsules (GOMCs), containing linseed oil as the healing agent. The nanometer-thick shells of GOMCs were built by the liquid crystalline assembling of graphene oxide (GO) sheets, forming at liquid-liquid interface in Pickering emulsions. The GOMCs were embedded into waterborne polyurethane matrix, enabling the facile fabrication of self-healing composite coatings on hot-dip galvanized steel surfaces. The inclusion of GOMCs in the composite coatings not only imparted self-healing properties to the coatings, but also improved their anticorrosion properties because of the physical barrier of the GO shell, leading to much better survival to the weather/marine environment and surface wear.