| 1. |
- Bjorkbacka, Asa, et al.
(författare)
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Role of the Oxide Layer in Radiation-Induced Corrosion of Copper in Anoxic Water
- 2016
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Ingår i: The Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 120:21, s. 11450-11455
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Tidskriftsartikel (refereegranskat)abstract
- The influence of a pregrown copper oxide layer on radiation-induced corrosion of polished copper in pure anoxic water has been explored. The resulting amount of copper oxide formed during corrosion was measured with cathodic reduction, and the concentration of dissolved copper in solution was measured with inductively coupled plasma atomic emission spectroscopy. The identity of corrosion products and their topography was determined with Raman spectroscopy and scanning electron microscopy, respectively. Nonirradiated reference samples were analyzed for comparison. The results show that radiation-induced corrosion of copper in anoxic water is significantly more effective on preoxidized copper compared to polished copper. The total amount of oxidized copper exceeds the amount expected solely from radiation chemistry of water by more than 3 orders of magnitude. To explain this discrepancy a mechanism is suggested where the hydroxyl radical (HO center dot) is the main radiolytic oxidative species driving the corrosion process. If the thermodynamic driving force would be large enough (such as for the hydroxyl radical or its precursor, H2O+), the oxide layer could conduct electrons from the metal to the hydroxyl radicals formed at oxide surfaces. The formation of an oxide layer will then result in an increased reactive surface area partly accounting for the observed discrepancy.
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| 2. |
- Björkbacka, Åsa, et al.
(författare)
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Radiation Induced Corrosion of Copper in Humid Air and Argon Atmospheres
- 2017
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Ingår i: Journal of the Electrochemical Society. - : Electrochemical Society. - 0013-4651 .- 1945-7111. ; 164:4, s. C201-C206
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Tidskriftsartikel (refereegranskat)abstract
- Corrosion of copper is a key-issue in the safety assessment of deep geological repositories for spent nuclear fuel utilizing copper coated canisters to isolate the spent nuclear fuel from the surrounding environment. Of particular interest is the radiation induced corrosion attributed to the inherent radioactivity of the spent nuclear fuel. In this work we have studied the radiation induced corrosion of copper in humid air and argon atmospheres. Polished copper cubes were gamma irradiated in the environments mentioned above at ambient temperature. Reference samples, not irradiated but otherwise treated under the exact same conditions as the irradiated samples, were used throughout the study. The oxide layers formed during radiation exposure were studied using cathodic reduction, infrared reflection/absorption spectroscopy, and the surfaces were examined using scanning electron microscopy. When possible, the concentration of copper in solution was measured using inductively coupled plasma atomic emission spectroscopy. The experimental results clearly show that radiation induced corrosion of copper in humid air as well as in humid argon is significantly more extensive than the corresponding process in anaerobic water. This is well in line with the recently proposed mechanism for radiation-induced corrosion of copper in anaerobic water. The very similar behavior of copper irradiated in humid air and in humid argon implies that the radiolytically formed HNO3 in the case of humid air has negligible impact on the radiation-induced corrosion compared to the radiolytically formed hydroxyl radical.
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| 3. |
- Göthelid, Mats, et al.
(författare)
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Hexane selenol dissociation on Cu : The protective role of oxide and water
- 2017
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Ingår i: Applied Surface Science. - : Elsevier. - 0169-4332 .- 1873-5584. ; 423, s. 716-720
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Tidskriftsartikel (refereegranskat)abstract
- Hexane selenol (CH3(CH2)5SeH) was adsorbed from gas phase in ultra-high vacuum on polycrystalline Cu and studied with synchrotron radiation based photoelectron spectroscopy (PES) and Near edge X-ray absorption fine structure spectroscopy (NEXAFS). Adsorption was done on a bare copper surface at room temperature (RT), on a thin oxide on Cu at room temperature, and on a thin layer of water on Cu at 140 K.
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| 4. |
- Hosseinpour, Saman, et al.
(författare)
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Atmospheric corrosion of Cu, Zn, and Cu-Zn alloys protected by self-assembled monolayers of alkanethiols
- 2016
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Ingår i: Surface Science. - : Elsevier. - 0039-6028 .- 1879-2758. ; 648, s. 170-176
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Tidskriftsartikel (refereegranskat)abstract
- In this article results from earlier studies have been compiled in order to compare the protection efficiency of self-assembled monolayers (SAM) of alkanethiols for copper, zinc, and copper-zinc alloys exposed to accelerated indoor atmospheric corrosion conditions. The results are based on a combination of surface spectroscopy and microscopy techniques. The protection efficiency of investigated SAMs increases with chain length which is attributed to transport hindrance of the corrosion stimulators in the atmospheric environment, water, oxygen and formic acid, towards the copper surface. The transport hindrance is selective and results in different corrosion products on bare and on protected copper. Initially the molecular structure of SAMs on copper is well ordered, but the ordering is reduced with exposure time. Octadecanethiol (ODT), the longest alkanethiol investigated, protects copper significantly better than zinc, which may be attributed to the higher bond strength of Cu-S than of Zn-S. Despite these differences, the corrosion protection efficiency of ODT for the single phase Cu20Zn brass alloy is equally efficient as for copper, but significantly less for the heterogeneous double phase Cu40Zn brass alloy.
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| 5. |
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