Antibacterial Corrosion Inhibitor for the Protection of Mild Steel in 1 M HCl Solution

Mild steel is widely utilised as a construction material because of its mechanical qualities and low cost but its weak acid corrosion resistance limits its application. The ability of parachlorobenzoylhydrazinylmethane (PCBHM) as a corrosion inhibitor and antibacterial agent was investigated by gravimetric measurements, density functional theory (DFT) and antibacterial studies. The weight loss results showed that the inhibition efficiency of PCBHM to prevent the corrosion of mild steel in 1.0 M HCl increased with concentration from 100 to 500 ppm, with a maximum inhibition efficiency of 96.5 % at 500 ppm. The inhibitory action of the inhibitor was explained in terms of adsorption on the mild steel surface which follows a Langmuir isotherm via physisorption and chemisorption mechanisms. PCBHM has significant corrosive protection efficacy and antimicrobial activity similar to the common antibacterial agent, chloramphenicol. The novelty of this work was the investigation of the protective response of PCBHM which was analysed analytically on the corrosion of mild steel in 1.0 M hydrochloric acid using gravimetric and thermometric techniques and its antibacterial effects.