Influence Of Chloride Ion In Simulated Uterine Solution On Corrosion Behavior Of Microparticulate And Nanoparticulate Copper

The corrosion behavior of copper microparticles and copper nanoparticles in NaClsolution of different concentrations were studied in this paper. A ultravioletspectrophotometer was used in this study to detect the releasing law of coppermicroparticles and copper nanoparticles immersed in different concentrations of NaClsolution, and the potentiodynamic polarization curves of copper microparticles and coppernanoparticles were obtained in various concentrations NaCl solutions. The results of thetests shows that the corrosion rates of both copper microparticles and copper nanoparticlesincrease with the increasing of Cl-content in NaCl solutions, and the corrosion rates ofcopper nanoparticles is much higher than those of copper microparticles in the samecorrosion media. Besides, the maximal cupric ions concentration obtained from the coppernanoparticles is much higher than that obtained from the copper microparticles in the sameNaCl solution, and the former increase while the latter decrease with the increasing of Cl-concentration in NaCl solution.To further understand the mechanism of corrosion of copper microparticles andcopper nanoparticles in NaCl solutions, the cyclic voltammograms of coppermicroparticles and copper nanoparticles were obtained in distilled water and181.88mmol/L NaCl solution. The results show that the corrosion behavior of copper particles isdifferent between in distilled water and in NaCl solutions, especially for coppernanoparticles. Besides, the corresponding peaks of copper nanoparticles are different fromthose of copper microparticles in amount and location, indicating that the corrosionmechanism of copper microparticles is different from that of copper nanoparticles.To confirm the results drawn from the previous experiments, SEM and XRD and pHvalues of the immersion solutions on different immersion time points was employed toevaluate microstructures of the original copper microparticles, the original copper nanoparticles, the corrosion products of copper microparticles and the corrosion productsof copper nanoparticles, and the value of the immersion solutions on different immersiontime points were tested. The results of SEM show that the size of copper microparticles isabout100times of the size of copper nanoparticles, leading to the surface energy ofcopper nanoparticles much higher than copper microparticles. XRD patterns shows thatthe corrosion products of copper microparticles are different from those of coppernanoparticles as well, leading to the differences of surface energy and composition of theoriginal particles. Finally, mechanism of the corrosion of copper particles in NaCl solutionis deduced based on the experiments obove.