Comparative studies of Tris-HCl, HEPES and NaHCO₃/CO₂ buffer systems on the biodegradation behaviour of pure Zn in NaCl and SBF solutions

The influence of solution pH and buffer system on the degradation behaviour of pure Zn was investigated and in vitro methodology that can better simulate in vivo corrosion was explored. Electrochemical approaches and immersion tests were performed in buffered pseudo-physiological solutions. It revealed that solution pH affected the degradation and can be adjusted by Tris-HCl, HEPES and NaHCO₃/CO₂. The pH-control ability and associated influence of three buffer systems varied in NaCl solution and SBF, owing to the introduction of different inorganic ions. Tris-HCl and NaHCO₃/CO₂ buffered SBF were recommended for future evaluation of biodegradation behaviour of Zn and its alloys.