Characteristics of copper corrosion in simulated uterine £uid in the presence of protein
- نوع فایل : کتاب
- زبان : انگلیسی
- مؤلف : JIANJUN ZHU, NAIXIN XU* and CHENGDIAN ZHANG
- چاپ و سال / کشور: 2000
Description
In order to acquire more knowledge of the performance of copper-bearing intrauterine devices (Cu-IUDs), corrosion behavior of copper in a simulated uterine £uid was investigated in the presence of proteins. The proteins studied included serum albumin, g-globulin and hemoglobin. Electrochemical polar- ization resistance measurements indicated that, in all cases under study, the corrosion rate of copper declined with time and the proteins always increased the rate. Moreover, di،erent kinds of protein showed di،erent dependence of copper corrosion rate on protein level. Addition of serum albumin initially raised the copper corrosion rate; however, the higher albumin concentration resulted in less promotion of the corrosion. X-ray di،raction (XRD) of the specimen surface showed that, both in the presence and absence of serum albumin, cuprous oxide was the only corrosion product, even though at higher concentrations of albumin less cuprous oxide was formed. This implies that serum albumin does not alter the corrosion mechanism. Electrochemical cathodic reduction of the oxide ¢lm and chemical analysis of solution after corrosion testing proved that the proportion of soluble ionic copper in the whole corrosion products varied with the albumin level. The copper corrosion rate in the presence of g-globulin or hemoglobin increased monotonically with increasing concentration of the protein. These three proteins shifted the corrosion potential of copper towards negative. It could be inferred that the proteins accelerated the anodic dissolution process of copper and hence enhanced its corrosion.
Advances in Contraception, 1999; 15: 179^190. #2000Kluwer Academic Publishers. Printed in theNetherlands
