Electrospun cassava starch/poly(ethylene oxide) nanofibers incorporated with eugenol as a corrosion inhibitor for mild steel in HCl environment

Abstract Mild steel, also known as carbon steel, is a key material that is often used as a construction material in many industries. It mainly consists of a high amount of iron with a low carbon content. Due to the absence of alloying elements, mild steel lacks the ability to form a stable protective oxide film, leading to low corrosion resistance. Therefore, the introduction of corrosion inhibitors becomes essential to protect it in aggressive environments. This study investigates the potential of electrospun cassava starch/poly(ethylene oxide) (PEO) nanofibers incorporated with eugenol as a corrosion inhibitor for mild steel in 0.50 mol L-1 HCl solutions. Since cassava starch, PEO and eugenol contain heteroatoms, they form protective barriers on the mild steel surface to reduce corrosion. More importantly, mild steel specimens coated with nanofibers formed through electrospinning of cassava starch and PEO blend enhance the corrosion inhibition efficiency when dipped in eugenol. Mass loss measurements, electrochemical impedance spectroscopy (EIS), Tafel plot analysis and open-circuit potential (OCP) measurements independently verify the corrosion inhibition ability of the above electrospun system in the presence of eugenol. The highest inhibition efficiency of 94.0% is achieved with mild steel specimens coated with nanofibers of 98 nm dimensions formed with electrospun cassava starch/PEO mixed in 1:3 ratio followed by dipping in eugenol for 24 h. Moreover, the effect of pitting corrosion agents, such as NaCl and temperature on corrosion inhibition was also investigated.