Corrosion Protection Evaluation of Copper Coated with a Block Copolymer and Block Coploymer/Carbon Black Nanoparticles in 3 wt% NaCl Solution

This paper presents a successful preparation of SEBS (a copolymer polystyrene-block-poly (ethylene-ran-butylene)-block-polystyrene) and SEBS-CB (SEBS-Carbon Black nanoparticles) coatings on a copper surface following a well-defined immersion protocol. Such coatings ' protection capacity was tested in a 3 wt% NaCl medium using potentiodynamic polarization, cyclic voltammetry (CV), and electrochemical impedance techniques (EIS). The electrochemical measurements indicate that SEBS and SEBS-CB are cathodic-type inhibitors mainly hindering the diffusion of oxygen molecules toward the copper substrate. It also indicates the decrease in chloride ion attack on the coated copper layer. Not only that, but it also affirms the decrease in CuCl2-s transport to the bulk solution, resulting in our sample being further protected at more positive potential. Cu-SEBS-CB electrodes showed a slight improvement in corrosion protection compared to Cu-SEBS electrodes. pi-pi stacking was associated with improving the performance of these coatings. The keys functions of incorporating CB are improving the electrode conductivity and having a denser and more compact coating than that without CB. The order of inhibition efficiency obtained by potentiodynamic polarization is in good agreement with the results achieved by electrochemical impedance spectroscopy. Also, the inhibition efficiency of Cu-SEBS and Cu-SEBS-CB increases with increasing the ratio of SEBS. Adsorption of SEBS and SEBS-CB on copper surface follows the Langmuir isotherm.