Influence of oxygen, albumin and pH on copper dissolution in a simulated uterine fluid

Abstract

Objectives The aim of this paper is to study the influence of albumin content, from 5 to 45 g/L, on copper dissolution and compounds composition in a simulated uterine solution.

Methods Experiments were performed in atmospheric pressure conditions and with an additional oxygen pressure of 0.2 atmospheres, at 6.3 and 8.0 pH values, and at a temperature of 37 ± 0.1° C for 1, 3, 7, and 30 days experimentation time.

Results The copper dissolution rate has been determined using absorbance measurements, finding the highest value for pH 8.0, 35 g/L albumin, and with an additional oxygen pressure of 0.2 atmospheres: 674 μg/day for 1 day, and 301 μg/day for 30 days. X-ray photoelectron spectroscopy (XPS) results show copper(II) as the main copper oxidation state at pH 8.0; and copper(I) and metallic copper at pH 6.3.

Conclusions The presence of albumin up to 35 g/L, accelerates copper dissolution. For high albumin content a stabilisation on the copper dissolution takes place. Corrosion product layer morphology is poorly protective, showing paths through which copper ions can release.

• Copper
• Simulated uterine fluid
• Albumin
• Oxygen pressure
• pH
• XPS and SEM