✍ Scribed by T.M.H. Saber; A.A. El Warraky
No coin nor oath required. For personal study only.
The phenomenon of dezincification of o-brass in 4% NaCl solution (synthetic sea water) following polarization at various potentials was studied using XPS and AES surface analytical techniques. The electrolyte was simultaneously analyzed by atomic absorption. At potentials more negative than the steady state open-circuit potential (EJ of brass, dissolution of both copper and zinc was restricted by the values of the solubilities of Cu,O and ZnO. At potentials more positive than E, dissolution of o-brass occurred with 100% current efficiency with a rate two orders of magnitude higher than that measured at negative potentials. XPS analysis of the alloy surface following polarization proved the formation of CuCl and two forms of ZnO. Dissolution of copper is assumed to occur through CuC12 -where that of zinc is suspected to occur through HZn02. The two metals go into solution in a ratio comparable to that of the alloy. Following prolonged polarization, xps spectra indicated the redeposition of metallic copper from solution on top of the CuCl precipitate. E = Potential, Vs (SCE), mV id = Current density mA/cm2 XPs = X-ray photoelectron spectroscopy AES = Auger electron spectroscopy
📜 SIMILAR VOLUMES
Mineral composition of grain and flour in 14 promising triticule strains from lndia are reported. The mean values for whole grain, i. e. Ca (0.47 mg/g), P (2.70 mg/g), K 4.60 mg/g, Na (352 pg/g), Zn (41.6 pg/g), Cu (7.0 pg/g), Fe (73.4 pg/g) and Mn (33.6 pg/g) were obtained as compared to those of f