Ti₃C₂T_x MXene-Polyaniline Nanocomposites for Redesigning Epoxy Coatings to Improve Anticorrosive Performance

Abstract

Corrosion, a gradual deterioration of metallic bodies, poses significant risks, along with massive monetary and material losses. Surface coatings enriched with corrosion inhibitors and nanostructural fillers play vital roles in protecting the metal substrate against the corrodents. In the present work, Ti3C2T x MXene, synthesized by selective chemical etching of an aluminum layer from the Ti3AlC2 MAX phase, is used as a platform material to interfacially grow the polyaniline (emeraldine salt form; PANI-ES) via oxidative polymerization of aniline for preparing the Ti3C2T x -PANI-ES nanocomposites. The reinforcement of the epoxy matrix via multiple interactions with ample nitrogen and oxygen functionalities of Ti3C2T x -PANI-ES nanocomposites enhanced the structural compactness, elastic modulus, and hardness of the resultant epoxy coatings. The Ti3C2T x -PANI-ES nanocomposites as a protective filler to the epoxy coating improved the corrosion inhibition properties in the accelerated corrosive environment (3.5% saline solution). The Ti3C2T x -PANI-ES increased the total electrochemical impedance of epoxy coating by 11 orders of magnitude, which is further corroborated by the protection of the underlying steel substrate under continuous exposure to salty fog. The Ti3C2T x MXene as a structural barrier impedes the diffusion of corrodents, and the electroactive PANI-ES minimizes the galvanic events by trapping the electrons released during the anodic oxidation of iron and forms a passive layer to protect the underlying mild steel. Therefore, Ti3C2T x -PANI-ES nanocomposites can be promising materials for corrosion inhibition applications.