Corrosion Of Copper In Water Research Articles

On the mechanism of γ-radiation-induced corrosion of copper in water

Radiation-induced corrosion of the copper canister used to contain the spent nuclear fuel in future geological repositories is a process of potential importance for the long-term safety. In recent years, several experimental studies have been conducted to elucidate the mechanism of this process. However, experimental observations and numerical simulations based on the proposed mechanism are not in agreement. In this work we have explored the mechanism further. Based on a series of experimental observations we propose a new mechanism where the corrosion of copper is driven by radiolytically produced O2.

Corrosion of copper in water and colloid formation under intense radiation field

Radiation effects of photons on corrosion and colloid formation of copper (Cu) in water were investigated as a model for the cooling water for electromagnets at accelerator facilities. Irradiation experiments were carried out at a 60Co γ-ray irradiation facility and an electron linear accelerator facility; production of soluble Cu species and relatively-large particulate Cu species (>200 nm) were promoted by γ-ray/bremsstrahlung irradiations. The results imply that particulate Cu species are initially generated at the Cu/water interface, grow up, and are finally released into water phase as relatively-large particles. These characteristic radiation effects may be related with production of reactive species in water.

Some scientific considerations on the article: ?Scientific basis for corrosion of copper in water and implications for canister lifetimes? published by F. King and C. Lilja

Some scientific considerations on the article: ?Scientific basis for corrosion of copper in water and implications for canister lifetimes? published by F. King and C. Lilja

Al2O3 and TiO2 Atomic Layer Deposition on Copper for Water Corrosion Resistance

Al(2)O(3) and TiO(2) atomic layer deposition (ALD) were employed to develop an ultrathin barrier film on copper to prevent water corrosion. The strategy was to utilize Al(2)O(3) ALD as a pinhole-free barrier and to protect the Al(2)O(3) ALD using TiO(2) ALD. An initial set of experiments was performed at 177 °C to establish that Al(2)O(3) ALD could nucleate on copper and produce a high-quality Al(2)O(3) film. In situ quartz crystal microbalance (QCM) measurements verified that Al(2)O(3) ALD nucleated and grew efficiently on copper-plated quartz crystals at 177 °C using trimethylaluminum (TMA) and water as the reactants. An electroplating technique also established that the Al(2)O(3) ALD films had a low defect density. A second set of experiments was performed for ALD at 120 °C to study the ability of ALD films to prevent copper corrosion. These experiments revealed that an Al(2)O(3) ALD film alone was insufficient to prevent copper corrosion because of the dissolution of the Al(2)O(3) film in water. Subsequently, TiO(2) ALD was explored on copper at 120 °C using TiCl(4) and water as the reactants. The resulting TiO(2) films also did not prevent the water corrosion of copper. Fortunately, Al(2)O(3) films with a TiO(2) capping layer were much more resilient to dissolution in water and prevented the water corrosion of copper. Optical microscopy images revealed that TiO(2) capping layers as thin as 200 Å on Al(2)O(3) adhesion layers could prevent copper corrosion in water at 90 °C for ~80 days. In contrast, the copper corroded almost immediately in water at 90 °C for Al(2)O(3) and ZnO films by themselves on copper. Ellipsometer measurements revealed that Al(2)O(3) films with a thickness of ~200 Å and ZnO films with a thickness of ~250 Å dissolved in water at 90 °C in ~10 days. In contrast, the ellipsometer measurements confirmed that the TiO(2) capping layers with thicknesses of ~200 Å on the Al(2)O(3) adhesion layers protected the copper for ~80 days in water at 90 °C. The TiO(2) ALD coatings were also hydrophilic and facilitated H(2)O wetting to copper wire mesh substrates.

Scientific basis for corrosion of copper in water and implications for canister lifetimes

The Swedish Nuclear Fuel and Waste Management Company has developed a method for safely disposing spent nuclear fuel, which involves encapsulation of the waste in copper canisters and burying it deep in the stable crystalline rock of the Fenno-Scandian shield. The design life of the canisters in the so called KBS-3 design is in excess of 100 000 years. These long canister lifetimes are a consequence of a number of factors involving the properties of the material and the nature of the near field environment in the KBS-3 repository. One of these factors, namely the thermodynamic stability of copper in O2 free water in the absence of sulphide, has been questioned. This paper critically reviews the evidence for and against the claim that water oxidises copper, and discusses the implications for canister lifetimes even if the proposed mechanism is correct. Even though the evidence presented in support of the proposed mechanism is not compelling, the Swedish Nuclear Fuel and Waste Management Company is actively engaged in ongoing research and development on the topic.

Hydrogen gas production during corrosion of copper by water

This paper considers the corrosion of copper in water by: (1) short term, open system weight measurements and (2) long term, closed system immersion in distilled water (13,800 h) without O 2 at 21–55 °C. In the latter experiments, the hydrogen gas pressure is measured above the immersed copper and approaches ∼10 −3 bar at equilibrium. This pressure is mostly due to copper corrosion and greatly exceeds that in ambient air. Accordingly, this measured hydrogen pressure from copper corrosion increases with temperature and has the same dependency as the concentration of OH − in the ion product [OH −] [H +].

Pitting corrosion of copper in waters with high pH and low alkalinity

Corrosion of copper pipes has been associated with waters with high pH and low alkalinity that also contain significant levels of chloride and sulfate. This study systematically evaluated the effect of pH, alkalinity (or dissolved inorganic carbon [DIC]), orthophosphate, and sulfate on the nature of copper corrosion using a pilot‐scale experimental pipe loop system. Experiments were conducted in the absence of silica, aluminum, or organic carbon, which previously have been linked to pitting corrosion in drinking water systems, and all test waters contained moderate levels of chloride. The study also investigated the effect of chlorine concentration and form of chorine on copper‐pitting corrosion. Results showed that pitting corrosion of copper pipes was reproduced in the pilot‐scale systems after only 91 days of operation. Pitting corrosion occurred in water with low chlorine concentration and DIC and in pH 9 water in the presence of chloride. Pitting was not observed at pH 6.5 and 7 and was evident at pH 8 only when higher chlorine levels were maintained. Sulfate was not necessary to develop pitting corrosion; however, it did affect the composition of the corrosion by‐products

Comments on hydrogen evolution from the corrosion of pure copper

Some comments are given on the experimental conditions in two recent communications in this journal which deal with copper corrosion in water. Also some additional experimental information and thermodynamic considerations on a possible hydrogen release from copper in water is given, including a very simple and straightforward experiment.

ChemInform Abstract: Hydrogen Evolution in Corrosion of Copper in Pure Water.

AbstractH2 is evolved during corrosion of copper in water, i.e. copper is oxidized by water.

Modeling copper corrosion in water with low conductivity by using electrochemical techniques

Corrosion rates of copper in synthetic water were measured by using an electrochemical method whose results were verified by coupon tests. The synthetic water was prepared to simulate the concentrations of the principal inorganic anions and cations found in a drinking water supply. Control of the corrosion rate by either chemical reaction, diffusion of reactive species through the oxide film, or diffusion of reactive species through the solution was considered. Experimental conditions included various combinations of temperature (5° C, 15° C, or 25° C) and pH (6.0‐8.3). In general, the corrosion rate decreased with an increase in pH and a decrease in temperature, although the rate varied with the type of control.

Accelerated Corrosion of Copper in Flowing Pure Water Contaminated with Oxygen and Sulfide

Abstract Studies of the corrosion of OFHC copper in water contaminated with sulfide, oxygen, or sulfide plus oxygen have shown that the presence of either sulfide (48 to 1940 ppb) plus low oxygen (29 to 60 ppb) or oxygen alone (865 to 6950 ppb) leads to low corrosion rates. However, when both sulfide and oxygen are present in certain concentration ranges, dramatic increases in the corrosion rate result. As little as 56 ppb sulfide in water containing 870 ppb oxygen can increase the corrosion rate by an order of magnitude. A mechanistic model that explains the synergism has been developed.

Copper Corrosion: I . Thermodynamic Aspects

Thermodynamic data for reactions concerned in the corrosion of copper in waters containing dissolved oxygen and carbon dioxide are assembled and are used to demonstrate certain features of the corrosion processes. These include the extreme vulnerability of copper to attack, the critical effects of oxygen, and the inadequately protective properties of films of solid corrosion products. Confirmation and extension of these conclusions are obtained by experimental studies of systems derived from copper, cuprous oxide, cupric oxide, malachite, and azurite in water kept in equilibrium with gaseous atmospheres containing known partial pressures of oxygen and carbon dioxide. It is shown, inter alia, that cuprous oxide is highly susceptible to dissolution, both by disproportionation and oxidation, and that metallic copper dissolves in such media at a constant rate, despite the accompanying film growth, accumulation of cupric bicarbonate in solution, and rise of pH. The maximum rate of dissolution is attained at a molar ratio of in the gas phase, when a substantial oxide film is formed on the metal.