corrosion inhibition by piliostigma thoningii extract on mild steel in acidic environment: rsm and molecular modeling approach

The study aimed to optimize the corrosion inhibition performance of an extract from pilliostigma thoningii stem bark on mild steel in 1m hcl environment using response surface methodology (rsm). the optimal inhibitor concentration, temperature, and reaction time were found to be 1.0 g/l, 333 k, and 1 hour, respectively, resulting in an inhibition efficiency of 93.75%. the inhibitor’s efficacy was confirmed through various analytical methods, including sem, ftir, and uv-visible spectroscopy. the results suggest that the experimental and predicted data are in reasonable agreement, showing that the quadratic model was the fittest for optimizing the inhibition process. the study identified 33 compounds through gc-ms, with pt-1, pt-2, and pt-3 being the major compounds. quantum chemical calculations and molecular dynamics simulations further confirmed the effectiveness of the three selected inhibitor molecules, with pt3 being the most effective. the study concludes that pilliostigma thoningii stem bark extract has the potential to be an effective corrosion inhibitor for mild steel in acidic environments.