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101.
The self-assembled monolayers (SAMs) of a series of substituted benzenethiol (BT) molecules, X-C6H4-SH (where X = meta-NH2, ortho-NH2, para-NH2, para-NHCOCH3, para-F, para-CH3 and para-CH(CH3)2), have been prepared by adsorption from a solution onto a fresh copper (Cu) surface pretreated by a nitric acid etch. The corrosion inhibition efficiency of the modified Cu surfaces in a sulfuric acid solution was investigated by electrochemical characterization. The protection afforded by the substituted functional groups on BT is strongly influenced by the type and the position of the substituent on the benzene ring. BT molecules without any substituent group on the ring are ineffective corrosion inhibitors, indicating that the chemical configuration is the key factor in determining the efficacy of the SAMs as barriers to electrochemically corrosive ions. It is further proposed that the steric hindrance offered by the substituted group in the SAMs plays a very important role in determining its barrier properties. 相似文献
102.
The reaction between copper and a mixture of SO2+O2 was studied at 973 and 1073 K. The experimental methods included optical microscopy, X-ray diffraction, scanning electron microscopy (SEM), energy-dispersive X-ray analysis, and radiotracer. It is concluded that the inward transport of oxidants through the scale as well as oxygen and sulfur dioxide liberation in the reactions taking place at phase boundaries suggest that secondary processes occur inside the oxide-sulphate layer. Therefore, Cu2O and CuOCuSO4 appear inside this layer. In the metal-consumption zone, a Cu2O layer forms, which contains small amounts of a sulfide phase near the metal-scale interface. 相似文献
103.
介绍了易门铜冶炼厂烟气制酸系统的技术改造工程.从工艺流程、设备复核、工艺参数、设备配置等方面阐述了技改的过程. 相似文献
104.
Masamitsu Watanabe Etsuko Toyoda Toshihiro Ichino Yasuhiro Higashi 《Corrosion Science》2007,49(2):766-780
Copper plates were exposed under sheltered outdoor conditions for up to one year, starting in September 2001 in Musashino City, Tokyo, a suburban area. Following various periods of exposure, the patinas on the plates were characterized to investigate their evolution by using X-ray fluorescence analysis, X-ray diffraction, field emission scanning electron microscopy, and glow discharge optical emission spectroscopy. The difference in the roles of sulfur and chlorine in the early stages of copper patination were identified by analyzing the depth profiles of these two elements. Sulfur was found on top of the patina as cupric sulfates such as posnjakite (Cu4SO4(OH)6 · H2O) or brochantite (Cu4SO4(OH)6). Brochantite appeared only after 12 months of exposure. In contrast, chlorine was found on the surface after only one month of exposure. It gradually penetrated the patina as the exposure period lengthened, forming copper chloride complexes. Chloride ions accumulated at the patina/copper interface, forming nantokite (CuCl), which promoted corrosion. 相似文献
105.
We have discovered a new Cu-based bulk metallic glass (BMG). Although of a simple Cu49Hf42Al9 ternary composition, the as-cast alloy is a monolithic, uniform BMG with a critical diameter as large as 10 mm. The width of the supercooled liquid region ΔTx and the reduced glass transition temperature Trg for this glass are 85 K and 0.62, respectively. In addition to its high glass-forming ability and high density of 11 g/cc, this BMG exhibits high ductility with a compressive plastic strain of 11–13%, making it a good candidate for applications as well as for studies of deformation behavior of Cu-based BMGs. 相似文献
106.
We analyzed the copper corrosion products that formed during a month in summer and a month in winter at three sites in Tokyo using several analytical techniques. The X-ray diffraction patterns revealed that cuprite Cu2O and posnjakite Cu4SO4(OH)6·H2O formed on copper exposed in summer. By contrast, only cuprite was found in winter exposed copper. The X-ray fluorescence results indicated that the amounts of sulfur and chlorine on the copper plates exposed in summer were much greater than those in winter. This could be explained by the change in particulate sulfate and sea salt concentrations. Depth profiling analysis by Auger electron spectroscopy revealed that the oxide layer formed in summer was thicker than that in winter. This difference in oxide layer thickness could have been due to the differences in temperature, relative humidity, and the amount of sulfur and chlorine on the copper plate. 相似文献
107.
运用统计学试验设计方法研究了不同的因素对铜常温发黑剂体系的性能影响.通过试验结果的统计分析,揭示了这些因素对体系的多种显著影响.更为重要的是本研究发现了多种因素间的双因素交互作用.而且这些交互作用的影响很难被传统的单因素试验发现.本研究结果可用于设计高性能的铜常温发黑剂. 相似文献
108.
通过对梅花形黄铜管一次拉伸成型的实验 ,研究了管坯的规格、管坯的状态、延伸系数、拉伸方式、工艺润滑及拉伸速度等工艺因素对梅花黄铜管凸筋高度充填的影响规律 ,这些结论对实际生产有一定的指导意义。 相似文献
109.
Polypyrrole (PPy) coatings have been deposited on iron from aqueous oxalic acid solution at different current densities. The polymer deposit obtained at a current density of 2 mA cm−2 yields strongly adherent and smooth PPy layers. The modification of the film by incorporation of copper microparticles using the cementation process was applied. The resulting PPy/Cu film electrodes were characterized by scanning electron microscopy and EDX analysis. The protective performance against corrosion of these films is evaluated by using open circuit potential monitoring in highly corrosive solution (3% NaCl + HCl, pH 1). The results obtained were promising in the protection against corrosion. 相似文献
110.