Abstract
Potentiodynamic polarization, electrochemical impedance spectroscopy, mass loss, and hydrogen evolutions techniques were used to investigate the effect of the plant extract Cystoseira myrica as corrosion inhibitor for aluminum in 1 M HCl. All those measurements showed that the effectiveness of inhibition increased with an increase in the extract dose and in temperature. The inhibition efficiency of the extract reached 93.7% at 300 ppm, 25 degrees C. Thermodynamic parameters of activation and adsorption were computed and discussed. Polarization curves showed that the extract studied behaves as mixed kind inhibitor. The Langmuir adsorption isotherm was obtained for the adsorption of the extract on the Al surface. Using the mass loss technique, it was revealed that adding KI enhances inhibitory efficiency from 77.3 to 91.6% owing to the synergistic effect. The surface analysis of aluminum was performed using different techniques. All other data approached were compatible and in line with each other.