▎ 摘　　要

The design of new materials with two or more functional groups must be strongly considered to achieve multifunctional coatings with outstanding properties such as active passive protection against corrosion, low-friction, antifouling, and sensing, among others. In this sense, nanocomposites based on solvent-free epoxy resin/bifunctionalized reduced graphene oxide layers with NH2 and NH3+ groups (ER/BFRGO) with super-anticorrosive properties are for the first time reported here. The amine groups (-NH2) act as cross-linker agents, which react with epoxy terminal groups from resin, thus closing the gap between the BFRGO layers and the polymeric matrix. Meanwhile, the ammonium ions (-NH3+) are effective trapping agents of negatively charged atoms or molecules (e.g., Cl-). This novel combination enables us to obtain nanocomposite coatings with passive-active protection against corrosion. ER/BFRGO deposited onto A36 mild steel exhibited a remarkably enhanced barrier against corrosion into a saline medium (1 M NaCl; 58.4 g/L), wherein the corrosion current density (i(corr)) was diminished 6 orders of magnitude (i(corr) = 5.12 x 10(-12) A/cm(2)), with respect to A36 mild steel coated only with ER (i(corr) = 2.34 x 10(-6) A/cm(2)). Also, the highest polarization resistance R-p = 6.04 x 10(7) Omega/cm(2) was obtained, which represents the lowest corrosion rate and corresponds to 3 orders of magnitude higher than A36 mild steel coated with ER (R-p = 1.43 x 10(4) Omega/cm(2)). The strategy of bifunctionalization proposed herein to obtain bifunctionalized reduced GO with NH2 and NH3+ groups has not been disclosed in the literature before; in consequence, this work opens a new pathway toward the design of smart materials based on multifunctional nanomaterials.