Zinc-doped sulfonated polyaniline tailored Multi-walled carbon nanotubes (Zn-SPANI-MWCNT); A novel nano-hybrid for designing a smart self-healable epoxy coating

• Published in: Journal of industrial and engineering chemistry (Seoul, Korea) 2023, 122(0), , pp.397-414
• Main Authors: Jalali, Hamid, Eslami-Farsani, Reza, Ramezanzadeh, Bahram
• Format: Article
• Language: English
• Subjects: Carbon nanotubes; Corrosion resistance; Epoxy coating; Nano-carrier; Self-healing; 화학공학
• ISSN: 1226-086X; 1876-794X
• DOI: 10.1016/j.jiec.2023.02.040

In this study, the oxidized carbon nanotubes (MC) were functionalized with sulfonated polyaniline (SPi) and Zn cations (Z) via a layer-by-layer (LBL) method. The characterization of MC particles with and without inhibitors was done by Fourier-transform infrared spectroscopy (FT-IR), X-Ray diffraction (XRD), Thermogravimetric analysis (TGA), and Field emission scanning electron microscopy (FE-SEM) methods. The active–barrier corrosion protection abilities of the coatings loaded with MC, MC.SPi, and MC.SPi.Z nano-carriers were evaluated by electrochemical impedance spectroscopy (EIS). The recorded logZ magnitudes at low frequencies for the MC.SPi.EP and MC.SPi.Z.EP samples were higher than 10, which illustrated that the loading of inhibitors on the MC could improve the distribution of nano-carriers in the coating and enhance the barrier index and stability of the coating. The EIS results attributed to the scratched coatings revealed that the MC.SPi.Z.EP total resistance was almost 8 times higher (83000 ohm.cm2) than the EP sample even after 72 hours. Higher adhesion and less penetration of corrosive agents into the interface of metal and coating were shown by pull-off and cathodic separation tests. In the cathodic separation test, the delamination of MC.SPi.Z.EP sample is reduced to 68% compared to EP, and also the pull-off strength is improved to 52%.