Synthesis, electrochemical and quantum chemical studies of some prepared surfactants based on azodye and Schiff base as corrosion inhibitors for steel in acid medium

Three nonionic surfactants based on azodye and Schiff base condensed with poly ethylene glycol were prepared. Their inhibition effect towards corrosion of steel in hydrochloric acid was investigated using electrochemical frequency modulation, electrochemical impedance spectroscopy, potentiodynamic polarization, quantum chemical calculations and molecular dynamic simulation. The data revealed that the prepared surfactants had the ability to inhibit corrosion reaction with good agreement between experimental and computational results. The adsorption of surfactants on the carbon steel surface in 1 M HCl was found to obey Langmuir isotherm. Polarization results showed that these inhibitors act as mixed-type inhibitors.