Corrosion inhibition and adsorption behavior of 1-(1-naphthalenylmethyl)quinolinium chloride on mild steel in hydrochloric acid medium

The inhibition behavior of 1-(1-naphthalenylmethyl) quinolinium chloride (nmq) on the corrosion of mild steel in 1.00 m hydrochloric acid has been investigated. weight loss measurements, potentiodynamic polarization and electrochemical impedance (eis) techniques were used to study the corrosion inhibition process. the results revealed that maximum corrosion protection was 99% at 50 ppm of nmq. polarization measurements indicate that inhibitor has mainly cathodic inhibition effects and therefore control of hydrogen evolution is done. from eis measurements it is found that charge transfer resistance values increased and double layer capacitance values decreased by increasing the inhibitor concentration. the adsorption of nmq on the mild steel follows the langmuir isotherm model, calculated value of adsorption free energy was (–43.6) kj mol-1 and adsorption constant was 107.5.