Interlayer growth of borates for highly adhesive graphene coatings with enhanced abrasion resistance, fire-retardant and antibacterial ability

Abstract

Surface coatings to protect materials from mechanical abrasion, fire and microbial colonization are associated with billion dollars of expenses across broad range of industrial, domestic and defence applications. Currently used protective coatings based on heavy metals, halogenated fire-retardation, and biocide agents have considerable environmental concerns due their toxicity, and lack of effectiveness with limited functionality. In this paper, we present engineering of new multifunctional coating based on graphene composites with the ability to provide “3-in-1” protective properties. These multiple functionalities were created with specially designed graphene composite by growing sodium metaborate (NaBO2·xH2O) crystals into graphene oxide (GO) layer during their reduction, which works synergistically as a surface binder, a flame-retardant additive, and an antibacterial agent. The testing of protective coating performances revealed an outstanding mechanical robustness (ASTM-class 4B), and the reduction of bacterial colonization up to ∼99.92%. The high flame retardant performance of the coated wood, and paper showed non-flammability, strong intumescent effect, and self-extinguishing ability during fire. These protective coatings based on graphene composites due the simplicity of their formulations, scalability, and outstanding performance offer a great potential for their industrial, structural, and environmental applications.