Corrosion behaviour of niobium in phosphate buffered saline solutions with different concentrations of bovine serum albumin

The corrosion behaviour of Nb was studied in phosphate buffered saline (PBS) solutions at a presence of 0–6 g L−1 bovine serum albumin (BSA). Addition of BSA to PBS solutions lowered the open circuit potential (OCP). OCP, polarization resistance and impedance increased over immersion time. The adsorption process of BSA on Nb surface was found to be faster than that of the PO43−. According to X-ray Photoelectron Spectroscopy (XPS) a competitive adsorption between PO43− and BSA was in effect during the immersion process. Based on the analysis of effective capacitances, a surface distribution of time-constants was proposed.

► Corrosion of Nb was investigated in phosphate buffered saline solutions.
► Addition of bovine serum albumin lowered the open circuit potential of Nb.
► Open circuit potential, polarization resistance and impedance increased with time.
► Bovine serum albumin molecules and PO43− competitively adsorbed on Nb surface.
► A surface distribution of time-constants was proposed.