Silanized MXene/Carbon Nanotube Composites as a Shielding Layer of Polyurethane Coatings for Anticorrosion

Two-dimensional Ti₃C₂T_x flakes have been studied as nanofillers in anticorrosive coatings, but their poor dispersion and interfacial interaction in coatings limit their application. In this study, we report silanized Ti₃C₂T_x/carbon nanotube (CNT) nanocomposite as a shielding layer for waterborne polyurethane (WPU) coatings, which makes the WPU coatings have enhanced anticorrosion properties. [3-(2-Aminoethylamino)-propyl] trimethoxysilane (AEAPTMS) is used to make the Ti₃C₂T_x surface electropositive, and sodium dodecylbenzene sulfonate (SDBS)-functionalized CNTs (S-CNTs) with negative charges on the surface are used to form highly dispersed composite nanofillers with Ti₃C₂T_x through electrostatic interaction. The functionalized surfaces of Ti₃C₂T_x and S-CNTs form an effective shielding layer in the coating, which effectively prevents the penetration of corrosive electrolytes. The results reveal that the AEAPTMS-functionalized Ti₃C₂T_x (A-Ti₃C₂T_x) and S-CNTs synergistically enhanced the anticorrosion performance of the WPU coatings. After 120 days of immersion, the impedance of the A-Ti₃C₂T_x/S-CNTs/WPU composite coating at 0.01 Hz is still 4.2568 × 10⁷ Ω cm². This improved performance depends on the good dispersibility and interface compatibility of the surface-functionalized Ti₃C₂T_x and S-CNTs in the coating layer. The prepared coating described in this study presents a great potential for practical protective coating applications like medical apparatus and instruments.