Effect of benzotriazole on corrosion inhibition of copper under flow conditions

• Benzotriazole corrosion inhibitor is tested on copper surface.
• Rotating cage is used to evaluate the effect of flow on the corrosion inhibition.
• Accelerated corrosion activity is reported for copper with increase in flow velocity in 3.5% NaCl test solution.
• Corrosion of copper is suppressed due to the adsorption of benzotriazole in flow condition.

The corrosion inhibition of benzotriazole on the copper surface is often investigated in static environment. The evidence for the protection of copper in dynamic flowing environment is limited. Hence, we investigated the corrosion control of copper in 3.5% NaCl solution in the presence of benzotriazole by a rotating cage. The flow test was carried out at different velocities 0.5–3.0 m/s (100–700 rpm). Copper showed accelerated corrosion activity with respect to the increase in the velocity in 3.5% NaCl test solution. However, benzotriazole added to the test solution reduced the corrosion attack on the copper. This clearly shows the adsorption of inhibitor on copper surface resulted in decreasing the mass loss by 4–5 times. The surface property was examined by using a scanning electron microscopy, atomic force microscopy and contact angle measurements. Adsorption of benzotriazole on copper surface follows the Langmuir adsorption isotherm.