ASSESSMENT OF THE INHIBITIVE ACTION OF L(-)-CYSTINE ON THE CORROSION OF COPPER ALLOY IN ACID SOLUTION

The corrosion inhibition performance of L(-) Cystine on copper alloy immersed in 2 M HNO3 so lution is investigated using weight loss, potentiody namic polarisation, electrochemical impedance spectroscopy, and scanning electron microscopy. Potentiodynamic polarization measurements con firmed that L(-)-Cystine behaved as mixed-type in hibitor. The highest corrosion inhibition efficiency was 98.99% at 298 K and decreased with increasing temperature. The Nyquist plots displayed an increase in the capacitive loops with increasing the concen tration of the inhibitor. The mechanism of inhibition obeys Langmuir isotherm. SEM images confirm the adsorption of L(-)-Cystine on the surface of the cooper alloy.