Exploring the novel environmentally friendly highly hydrophobic TiO2 coating for enhanced anti-corrosion performance of steel in potential industrial applications
Haewon Byeon, J. Sunil
Abstract
In this study, the structural and morphological properties and the corrosion resistance of mild steel (MS) plates were enhanced through the development of titanium dioxide (TiO 2 ) nanoparticles applied using the doctor blade coating method. X-ray diffraction (XRD) analysis, Rietveld refinement, and Fourier-transform infrared spectroscopy (FTIR) confirmed the successful synthesis of TiO 2 nanoparticles. The TiO 2 nanoparticles were bound to hydroxyl and carboxyl functional groups through electrostatic interactions. Field emission scanning electron microscopy (FESEM) images revealed the nanoparticles' minor agglomeration and spherical morphology. Additionally, particle size analysis showed a distribution range between 45 and 50 nm, with an average size of 48.56 nm. Surface wettability analysis demonstrated enhanced aqueous repellence of the MS plates after TiO 2 coating, particularly in NaCl, HCl, and KOH electrolytes. In addition, the TiO 2 nanoparticle coatings exhibited optimized nano-hardness values of 2.79 GPa, 1.51 GPa, and 2.89 GPa after electrochemical analysis, indicating an increase compared to the values measured before the electrochemical studies. The TiO 2 -coated MS samples exhibited significantly improved corrosion resistance compared to bare MS samples under 1 M H 2 SO 4 , 3 M KOH, and 3.5 wt% NaCl electrolytes. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) results revealed that the TiO 2 coating achieved the lowest corrosion current density (1.7839 μA/cm 2 ) and the highest protection efficiency (80.24 %) in NaCl electrolyte. Furthermore, EIS analysis indicated that the TiO 2 coating effectively impeded electrolyte penetration to the substrate, thereby providing superior corrosion resistance. • TiO 2 nanocomposite coating was developed where the pores of coatings have been encapsulated with polymer. • The wettability of the MS plate (contact angle) has been improved by TiO 2 coating. • The lowest coating damage and high corrosion resistance exhibited by TiO 2 nanoparticle coatings. • Coating stability improved due to the structural and morphological properties of TiO 2 .