Experimental and computational studies of the influence of non-ionic surfactants with coumarin moiety as corrosion inhibitors for carbon steel in 1.0 M HCl

[Display omitted] •Two surfactants were synthesized and characterized by FTIR and 1HNMR.•These compounds revealed high inhibition efficiency approached 97.47% for steel corrosion.•Their activity against corrosion confirmed by EFM, EIS, Polarization and weight loss techniques.•The experimental techniques supported by detailed quantum and Monte Carlo simulation study.•The protection of steel surface observed by SEM, EDX and AFM techniques. Herein, two nonionic surfactants were prepared followed by structure confirmation using H1NMR, IR and so their surface activity were studied. The application of these compounds in the field of acid corrosion inhibitors was investigated by several empirical and computational methods. Additionally, these compounds were found to be promising inhibitors with high activity as a function of concentration attained at 96.71 % for NIS I at 7.50 × 10–4 M. The mixed behavior of inhibition predominates in the polarization results and their occurrence on carbon steel surface belongs to Langmuir model by chemisorption. The presence of organic protective layer on carbon steel surface was confirmed by SEM, AFM and EDX techniques. Further interpretation of the inhibiting action was carried out via DFT and MC computations.