Synthesis of a novel metal-organic nanocomposite film (MONF) with superior corrosion protection performance based on the biomimetic polydopamine (PDA)-based molecules and Sm2O3 particles on the steel surface

In recent years, the nanocomposite films have been utilized for the metals' corrosion resistance enhancement. In this research, an eco-friendly samarium (III) and bio-compatible polyodopamine-based biopolymer have been applied to mitigate the corrosion of steel through the construction of a hybrid film with effective anti-corrosion potency. for this purpose, the PDA micro/nano-particles were synthesized via two well-known self-polymerization and oxidant-facilitated methods. Then, they were introduced into the Sm (III)-based chemical modification bath, and the resulting solutions were sprayed on the steel surface continuously. The steel panels coated with samarium-oxide nanofilm, as well as the Sm-PDA composite coating, have shown excellent water-repellency performance. Results evidenced 34% enhancement in the water contact angle (CA) and a 74% decrease in surface free energy (gamma(s)). Also, the SEM/EDS, XRD, and FT-IR analyses results revealed that the great surface hydrophobicity characteristic of the Sm-PDA modified sample is because of the synergistic effect of the nanoroughness of the Sm-nano film and the micro-scale roughness of the PDA particles. In addition, the XRD and FT-IR analysis outcomes affirmed the development of the films composed of the samarium oxide and PDA on the treated steel surface. The EIS and polarization test results revealed that via the steel surface treatment by Sm-PDA film, the total resistance (R-L) and i(corr) values increased/decreased for 4-fold and 65%, respectively. The R-t of the steel sample subjected to 0.6 M NaCl solution for 96 h is about 1163 (Omega.cm(2)), while this value for the Sm-treated, Sm-PDAS, and Sm-PDAO samples was 2778, 2915 and 4735 (Omega.cm(2)), respectively. Overall, the results confirmed the high water-proof and superior anti-corrosion potency of the composite Sm-PDA film. (C) 2020 Elsevier B.V. All rights reserved.