Copper corrosion inhibitors based on polyvinyl alcohol and silver nanoparticles

Abstract

Polyvinyl alcohol (PVA) and silver nanoparticles/poly(vinyl) alcohol system (nAg/PVA) were investigated as copper corrosion inhibitors in hydrochloric acid solution by electrochemical measurements, such as potentiodynamic polarization and cyclic voltammetry associated with the atomic force microscopy (AFM) and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM/EDS) analysis. The potentiodynamic curves processed as a semilogarithmic diagram were employed for corrosion current density (icorr) computing that reached the highest value for copper corrosion in uninhibited hydrochloric acid solution and the lowest value in nAg/PVA inhibitor presence, resulting in a picked-up inhibition performance, greater than 95%. Recording ten cycles of CV, the initiation, development and stability of upper-layer formed on the copper surface in the presence of inhibitors was confirmed. It can be asserted that PVA acts by the adsorption of Cu(II)-PVA complexes or crosslinked PVA-copper aggregates and additionally, in the presence of nAg/PVA of some compounds involving silver attached to PVA. AFM 3D images showed completely different morphologies of the copper surface layers formed in the absence and presence of inhibitors. Just like AFM, a more regular and uniform arrangement of the surface layer, due to the silver interconnected to PVA macromolecular chain, was displayed by scanning electron microscopy (SEM) images.