Influence of blackberry leaf extract on the copper corrosion behaviour in 0.5 M NaCl.

The research presented in this paper is focused on blackberry leaf extract (BLE) as a environmentally friendly corrosion inhibitor for copper in 0.5 M NaCl. The caffeic acid, quercetin-3-O-glucoside and kaempferol-3-O-glucoside were identified in BLE by using high-performance liquid chromatography (HPLC-DAD). The BLE functional groups were identified (ATR-FTIR). The electrochemical methods (potentiodynamic polarization, electrochemical frequency modulation and electrochemical impedance spectroscopy) show that BLE acts as a mixed type of inhibitor (max. IE is 97.19 %). The corrosion process is controlled by diffusion (BLE lower than 15 g/L) and charge transfer (15 g/L BLE).