Influence of Unzipped Multiwalled Carbon Nanotube Oxides-Epoxy Paint on the Corrosion Rate of Mild Steel in Marine Environment

In recent years, numerous innovative approaches have emerged to enhance the corrosion resistance of materials. This study investigates the effect of enhancing mild steel corrosion through the incorporation of unzipped multiwalled carbon nanotube oxides (UMCNO) into epoxy resin. Additionally, the effect of various operating parameters, such as temperature, UMCNO concentration, salt concentration, duration of exposure, and coating thickness, have also been considered in the study. The Box–Behnken method was used for experimental design and correlation of corrosion rate with various operating parameters, followed by analysis of variance of both five- and three-parameter models. Notably, despite variations in temperature and salt concentration, the corrosion rate remained negligible, confirming its suitability in various marine conditions. Furthermore, it was observed that the corrosion rate of mild steel coated with epoxy decreased with the addition of UMCNO. A corrosion rate of 0.182 mpy was observed for epoxy resin incorporated with 0.5 % UMCNO over a 14-day period, which is lower compared to other conditions. Electrochemical impedance spectroscopy and potentiodynamic polarization analysis showed higher corrosion-resistant properties in epoxy coating incorporated with UMCNO. In addition, it was evident from the contact angle measurement that the corrosion rate of mild steel was highly dependent on the concentration of UMCNO.