bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of Carbon Dioxide on the Atmospheric Corrosion of Zinc-Aluminium and Zinc-Aluminium-Magnesium Coated Steel
Authors: le Bozec Nathalie , Thierry Dominique , Le Gac Anne , Persson Dan 
Published: February 2020

The superior corrosion resistance of hot dip galvanized steel (HDG) alloyed with addition of Al and Mg compared to conventional zinc coating has been shown in numerous atmospheric conditions including accelerated tests and natural exposures. Despite significant work in understanding the mechanisms of corrosion of Zn-Al-Mg coatings, there are still gaps of knowledge such as, on the exact interactions between the complex microstructure of theses coatings and their corrosion properties. A large European (RFCS) project namely MicroCorr has been initiated in 2015 with the aims of better understanding these aspects. On task was to examine the effect of surface pH and contaminations as well as relative humidity and temperature on the corrosion performance of well-defined microstructures of alloyed zinc coatings with Al and Mg.
The present study focuses on the effect of carbon dioxide depletion on the atmospheric corrosion stability of Zn alloyed coatings compared to conventional HDG (Zn-0.2Al) and Galfan (Zn-5Al). Zn-Al-Mg and Zn-55Al coatings produced with various microstructures differing in the grain size were investigated in low and ambient concentration of CO2 with two levels of chloride concentration. In addition to mass loss data, the surface pH was measured using wide range pH indicator in agar-agar gel. The corrosion products were analyzed by FTIR spectroscopy and X-Ray diffraction.
The corrosion of HDG and zinc alloyed coatings with low content of Al and Mg was significantly enhanced in low CO2 conditions particularly at high chloride concentration and whatever the microstructure. This was connected to a high surface pH in the absence of CO2. Surprisingly, similar weight losses were measured for Zn-55Al coatings whatever the level of CO2 and no increase of surface pH was observed even in depleted CO2 conditions. However, important localised corrosion was observed for this coating
Atmospheric Corrosion Study to Painted Galvanized Steels Under Maritime, Industrial and Urban Conditions
Authors: Almeraya Facundo , Tiburcio Citlalli Gaona , Bernal Ponce Vanessa , Ramirez Reyes Jose Luis , Rodriguez-Gomez Francisco Javier , Barrios Carlos Paulino , Garcia R. Omar , Pedraza Juan Pablo , De la Garza Maribel , Vazquez Rodriguez Carlos 
Published: February 2020

The atmospheric corrosion, potentially destructive consuming sources and time, is the electrochemical process in which metals are deteriorate by atmospheric factors, that include the effect of climate conditions (periods of wetting and drying, temperature, humidity, rainfall, wind speed and direction, solar and ultraviolet radiation) and the effect of pollution (SO2, NaCl, CO2, NOx and solid particles). Another factor is that atmospheric corrosion involves chemical, electrochemical and physical process in three mater states (solid, liquid and gaseous) and two interfaces (solid/liquid and liquid/atmosphere).
In the present study painted galvanized steel sheets were exposed to different environments which include marine, industrial and urban conditions. The aim was study the corrosion behavior of the materials in the different climatic environments. To characterize the corrosion behavior a photographic register was done and an analysis of the layers in cross section with a scanning electron microscope.
SVET Study of Amines Attack of MnS Inclusions and the Consequences for Pitting and SCC Nucleation
Authors: Dick Luís Frederico Pinheiro , Lopes Natalia Feijó , Martins Tarso , Pritzel dos Santos Alvaro 
Published: February 2020

Sulfide inclusions are preferred nucleation sites for the localized corrosion of carbon and stainless steels. Thus, inclusions distribution and composition are important for the occurrence of pitting, crevice and the different forms of stress corrosion cracking. Amines are usually used for the removal of sulfides, with the precipitation of carbamates by the production of environmental friendly fuels with low S contents. On the other hand, amines are also used associated to formation/injection waters simultaneously to CO2 reinjection by the offshore oil production at high pressures, usually under the assumption that it will act as a corrosion inhibitor, as well.
In the present work, we show that amines, usually seen as corrosion inhibitors may enhance the attack to sulfide inclusions in unalloyed carbon steels. For this, artificial galvanic elements with carbon steel (AISI 1006) and MnS tablets (Figure 1.a and 1.c), simulating an inclusion, were studied by SVET (scanning vibration electrode technique) (Figure 1.b and1.d) and other techniques to evaluate the influence of amine (1% tetraethylenepentamine-TEPA) on the corrosion in Na2SO4solutions. Carbon steels (e.g. SAE1006) exposed to dilute sulfate solutions show the typical passive behavior with pitting at higher potentials. The amine “TEPA” shifts the pitting potential to higher values, as expected (Fig. 3a). MnS inclusions show the opposite behavior and its dissolution is promoted when TEPA is added in significant concentrations (Fig. 3b). Accordingly, SVET measurements show that the addition of TEPA can invert the galvanic pair formed by Fe-MnS (Fig. 1). At OCP, a synthetic MnS inclusion is attacked progressively by TEPA as Fig.2 shows for different exposure times. This has significant consequences for the initiation of pitting and stress corrosion cracking of steels, as verified by SVET measurements under simultaneous mechanical strain.

Figure 1
Localized Corrosion of Lean–Duplex Stainless Steel Reinforcements in Alkaline Solution
Authors: Bastidas David M. 
Published: February 2020

Understanding of localized corrosion mechanism of lean-duplex stainless in alkaline soltuiion is a key issue on construction and civil engineering industry, because the growing use and application of SS in those sectors. Duplex stainless steel improves the lifetime in service of reinforced concrete structures (RCS), thus combining good corrosion and mechanical properties. This research work studied corrosion behavior of duplex stainless steel rebars RCS: LDSS 2001, AISI 2304 and AISI 2205. Corrosion testing was performed in alkaline media under high chloride content conditions, [Cl–]= 4; 6 and 8%. Results allowed to elucidate chloride threshold on localized pitting corrosion, passive layer chemistry and electrochemical behaviour, for different duplex stainless steels reinforcements. The evolution with time of corrosion potential (E
corr) and polarization resistance (R
p) was studied. Polarization resistance and time constant (τ) were obtained by potentiostatic pulse technique.
Duplex stainless steel reinforcements revealed pitting corrosion after 6 months exposure in high chloride contained alkaline solutions (pH>12). Despite of pitting corrosion, a very low corrosion risk was found for duplex stainless steel used.
Spatially-Resolved Detection of Hydrogen Absorbed into Pure Iron Using Electrochromic Tungsten Oxide Thin Film
Authors: Sugawara Yu , Sakaizawa Yuto , Shibata Akihiro , Muto Izumi , Hara Nobuyoshi 
Published: February 2020

The initial stage of hydrogen embrittlement is hydrogen absorption. In atmospheric environments, hydrogen absorption into steel occurs as a result of the cathodic reaction during corrosion process. Because the hydrogen absorption behavior is sensitive to surface heterogeneity, it is an important subject to clarify the distribution of hydrogen absorption on steel surface for reducing the risk of hydrogen embrittlement.
Electrochemical hydrogen permeation cell developed by Devanathan et al.1) is effective in evaluating the hydrogen permeation rate and the diffusion coefficient of hydrogen, but it cannot measure the distribution of hydrogen absorption. A new and easy detection system to obtain the distribution of hydrogen absorbed into steel has been required.
We therefore fabricated a detection system for hydrogen absorbed into steel using WO3. After WO3 thin film was formed in the back side of an iron sheet (hydrogen detection side), hydrogen was absorbed into the iron sheet by the cathodic polarization in the front side (hydrogen entry side). Then, the change in the optical property of the WO3 thin film by hydrogen permeating through the iron sheet was examined.
Pure iron sheets 1 mm in thickness were used for the hydrogen detection test. Prior to the test, the surface of the hydrogen detection side was electrochemically plated with Pd. After the Pd-plating, the WO3 thin film was formed by reactive rf magnetron sputtering. The hydrogen evolution and absorption were performed by the potentiostatic polarization at -0.720 V in a 0.1 M H2SO4 solution. The surface of the WO3 film in the hydrogen detection side was observed by a video camera during the polarization.
The hydrogen detection test with the WO3 thin film shows that the color in the WO3 film gradually changed from a light blue to a dark blue. In addition, the color of the WO3 film around the area corresponding to the electrode region in the hydrogen entry side mainly altered. This result suggests that the optical property of the WO3 thin film in the hydrogen detection side changed by hydrogen absorbed into the iron sheet in the hydrogen entry side. XPS result shows that HxWO3 was formed at the dark blue area in the WO3 film after the hydrogen detection test. Therefore, the formation of HxWO3 by the absorption of hydrogen seems to result in the color change of WO3.
1) M. A. V. Devanathan and Z. Stachurski, Proc
.
Roy
. Soc., A270, 90-102 (1962).
Application of Channel Flow Double Electrode to pH Detection of Magnesium Dissolution during Anodic Polarization
Authors: Hoshi Yoshinao , Miyazawa Kei , Shitanda Isao , Itagaki Masayuki 
Published: February 2020

An elucidation of magnesium dissolution mechanisms is one of the key issues for wider usage of magnesium and its alloys in industry because the magnesium has high reactivity in aqueous solutions. The hydrogen evolution rate is increased with positive polarization from the open circuit potential, which is the so called negative difference effect (NDE).1,2 The real-time hydrogen measurement methods have been developed to investigate the NDE.3-6

Authors7 developed a pH sensing channel flow double electrode (CFDE) in order to investigate the pH changes due to the magnesium dissolution. Our group8-10 have been applied the CFDE for analysis of dissolution mechanisms of copper and copper alloys because the oxidation state of the metal ions dissolved from the metal working electrode (WE) can be detected by arranging a detecting electrode (DE) downstream of the WE. In the pH sensing CFDE, the DE was used as the pH sensor, namely, the hydroxide ions generated during the anodic polarization of magnesium WE can be detected at the pH sensor. It indicates that this method allows for the estimation of the hydrogen evolution rate from pH values without the hydrogen gas collection. In addition, a video recording of the WE surface was performed during the measurement in this system.
In the present study, the magnesium dissolution during anodic polarization was examined by the pH sensing CFDE. The relationship between the breakdown of the oxide film formed on the magnesium surface and increase of pH was discussed, and the hydrogen evolution rate was estimated from the pH values.
References

G. Song, A. Atrens, D. St John, X. Wu and J. Nairn, Corros. Sci., 39, 1981 (1997).

G. S. Frankel, A. Samaniego and N. Birbilis, Corros. Sci., 70, 104 (2013).

M. Curioni, Electrochim. Acta, 120, 284 (2014).

S. Lebouil, A. Duboin, F. Monti, P. Tabeling, P. Volovitch and K. Ogle, Electrochim. Acta, 24, 176 (2014).

S. Fajardo and G. S. Frankel, Electrochim. Acta, 165, 255 (2015).

Y. Hoshi, R. Takemiya, I. Shitanda and M. Itagaki, J. Electrochem. Soc., 163, C303 (2016).

Y. Hoshi, K. Miyazawa, I. Shitanda and M. Itagaki, J. Electrochem. Soc., 165, C243 (2018).

M. Itagaki, M. Tagaki, T. Mori and K. Watanabe, Corros. Sci., 38, 601 (1996).

Y. Hoshi, M. Itagaki, K. Tabei and I. Shitanda, J. Solid State Electrochem., 19, 3551 (2015).

Y. Hoshi, T. Oda, I. Shitanda and M. Itagaki, J. Electrochem. Soc., 164, C450 (2017).
Changes in Surface Potential Distribution Due to Hydrogen Permeated through Pure Iron
Authors: Yanai Kasumi , Hoshi Yoshinao , Shitanda Isao , Itagaki Masayuki , Katayama Hideki 
Published: February 2020

Further strengthening of steel materials is required in recent years from the viewpoint of energy saving and resource saving. However, hydrogen embrittlement is well known to be more sensitive to high-strength steel, and especially it is an urgent matter to solve the problem related to hydrogen embrittlement caused by corrosion. A technology for visualization of penetration or permeation hydrogen is required as a method to solve it. Katayama et al. report that distribution of permeated hydrogen can be visualized by surface potential measurement. In addition, they shows that the time during which the surface potential change due to permeated hydrogen is observed varies depending on the environment of the hydrogen detection side. However, it is not clear what the environment dependency of hydrogen observation time is attributed to. In this study, it is focused on the relative humidity as the environmental factor of the hydrogen detection side, and hydrogen permeation behavior was monitored by surface potential measurement under the environment of hydrogen detection side controlled at a variety of relative humidity.
Pure iron of 50 × 50 × 1 t (mm) was used as a sample. The hydrogen penetration surface of the sample was covered with a rubber type masking material except for about 2mm diameter of bare metal area. The sample was set in the apparatus, and the relative humidity in the acrylic container was controlled by the saturated salt method. Hydrogen penetration on the entry side was accelerated by cathodic polarization at - 2 mA/cm2 for 600s in 0.1M NaOH solution. After the polarization was stopped, the surface potential distribution of the hydrogen permeation side was measured every 10 minutes to 1 hour in the range of 20 × 20 (mm) with the copper plate as a reference．
Hydrogen evolution was observed only at the bare metal area of the sample during cathodic polarization, indicating that hydrogen penetration occurred only at the area. The humidity in the acrylic container was set to 68% with a saturated potassium chloride solution, 57% by a saturated sodium chloride solution, and 38% with a saturated magnesium chloride solution, respectively. The potential on the back side of the bare pure iron area gradually went down after cathodic polarization and shifted to the noble direction after showing the maximum. It took above 24 hours at 38% RH until a return to the original surface potential distribution, and that time decreased with an increase of relative humidity. In addition, the peak value of surface potential became lower as the relative humidity decreased.
(Invited) Using Surface Chemistry to Direct the Deposition of Nano-objects for Electronics
Authors: Hedlund Jenny K. , Ellsworth Ashley A. , Walker Amy V 
Published: February 2020

Nano-objects, including nanowires, nanopores, nanochannels and nanorings, and two-dimensional materials have many applications in electronics, sensing, energy conversion, optoelectronics and non-linear optics. One of the major challenges in the practical use of these structures is their integration into complex functional structures in a predictable and controlled way. In this talk we will describe our progress in synthesizing in situ with precise placement both nano-objects and films of two-dimensional materials, in particular transition metal dichalcogenides.
We have introduced two promising new techniques by which to direct the in situ growth of metallic and semiconducting nano-objects. ENDOM, or Electroless Nanowire Deposition On Micropatterned substrates, employs electroless deposition (ELD) to form metallic nanostructures on substrates. SENDOM, or Semiconductor Nanowire Deposition on Micropatterned surfaces, uses chemical bath deposition (CBD) to deposit semiconductor nanowires. Using these processes we demonstate the production of nanowires (diameters < 100 nm), mesowires (100 nm < diameter < ~3000 nm), nanorings, nanopores and nanochannels. These nanostructures can follow complex paths, such as arcs or right-angle bends, and are formed in parallel over cm2 areas. We will also discuss the formation of complex architectures, such as cross-bars, using these methods as well as the electrical properties of metallic nanowires deposited using ENDOM.
Two-dimensional materials, such as transition metal dichalcogenides (TMDs), are currently widely sought after for their application in semiconductor and nanoelectronic devices. By using templated substrates such as highly oriented pyrolytic graphite (HOPG) and sapphire we have successfully deposited large area ultra-thin molybdenum disulfide films using CBD. Further we show that the polytype of molybdenum disulfide can be altered between 2H and 1T by depositing the film on substrates with different surface energies. As the surface energy of the substrate is increased the MoS2 deposit changes from 2H to 1T. We also demonstrate that by patterning the substrate with areas of different surface energies that patterned 2H and 1T MoS2 films can be grown in situ.
(Invited) Spectroscopy and Photocurrents in All-Carbon Molecular Electronic Devices
Authors: Smith Scott R. , Najarian Amin , Supur Mustafa , McCreery Richard 
Published: February 2020

One or both contacts in all-carbon molecular junctions can be sufficiently transparent to permit optical spectroscopy as a probe of device structure, and photocurrent generation to investigate photon-induced electron transport. Current-voltage (JV) curves for aromatic molecules depends strongly on molecular structure when molecular layers are more than 5 nm thick, 1 and photocurrents were used to determine structural factors determining JV behavior. 2 As shown in the left figure below, the photocurrent spectrum tracks the molecular absorption spectrum determined directly in the completed molecular junction. A molecular bilayer consisting of an electron donor and acceptor layers yields significantly higher photocurrents, which depend on the order of the layer deposition (right image below). 3 The use of photocurrents and Raman spectroscopy for characterization of molecular junction structure and operation will be discussed. 4

(1) Morteza Najarian, A.; McCreery, R. L.; Structure Controlled Long-Range Sequential Tunneling in Carbon-Based Molecular Junctions; ACS Nano
2017, 11, 3542.
(2) Morteza Najarian, A.; Bayat, A.; McCreery, R. L.; Orbital Control of Photocurrents in Large Area All-Carbon Molecular Junctions; Journal of the American Chemical Society
2018, 140, 1900.
(3) Smith, S. R.; McCreery, R.; Photocurrent, Photovoltage and Rectification in Large-Area Bilayer Molecular Electronic Junctions submitted
2018.
(4) Supur, M.; Smith, S. R.; McCreery, R. L.; Characterization of Growth Patterns of Nanoscale Organic Films on Carbon Electrodes by Surface Enhanced Raman Spectroscopy; Analytical Chemistry
2017, 89, 6463.

Figure 1
Electrochemical Removal of Copper Contamination in Anodizing Baths
Authors: Perez Eduardo ALBERTO , Rivera Fernando Felipe , antaño Lopez Rene , Torres-González Julieta 
Published: February 2020

Electrolytic baths used in electroplating to make coatings or anodizing in metal parts are exposed to metal ions contamination (Cu2+, Pb2+, Zn2+ or their complexes in solution). Particularly, aluminum anodizing baths could have copper ions contamination that provoke spots and stain in the finished surface .The contamination is generated when the electrical copper connections partially lixiviates due to acid vapors generated in the process. It makes necessary to replace the bath in short periods of times and reprocess the imperfect pieces. These facts generate important economic losses.
Through the years the electrochemical technologies have been used in the treatment of contaminated effluents with metal ions, the treatment with electrochemical systems involves a challenge due to the often wide quantity of solution to be treated. The present work shows the preliminary results of copper removal from a 13% sulfuric acid bath used for aluminum anodizing, a lead cathode and 2024 aluminum pieces as anode. The experiments were carried out with a spent bath sample (with suspended solids). The concentration of copper in the solution was determinate by stripping voltammetry, as high as 200 ppm. Using XRD and ICP-MS it was found that the solids contained complexes of Cu with Pb, which means that the cathode (lead) used in the anodizing process dissolves in presence of Cu2+. The potential interval in which it is possible to carry out the deposition of copper was identified by cyclic voltammetry. The cell potential range in which it is possible to deposit copper (considering a Cu electrode as cathode and Pb electrode as anode) was calculated from the curves obtained in linear sweep voltammetry. The obtained cell potentials were then tested in a two electrodes cell configuration, and the best results were obtained at 1.3V. The copper removal achieved was 65% in 3 hours of operation.
Optimized Process Conditions for Hydrogen Peroxide Generating Gas Diffusion Electrodes
Authors: Muddemann Thorben , Kunz Ulrich , Haupt Dennis René , Sievers Michael 
Published: February 2020

Due to increasingly stringent environmental regulations for dealing with production residues, the purification of persistent residues have moved into research focus. Therefore, the inner recycling of process waters as a secondary raw material is getting continuously more relevant.
In search for new and efficient methods to purify process waters, electrochemical processes have moved to an aspiringly research emphasis. Especially electrochemical oxidation process are receiving much attention, in which strong oxidants are generated in situ, either directly on the electrode surfaces or indirectly, for instance through chemical trace substances (hypochlorite for example).
An innovative concept for removing trace elements is a combination of a boron-doped diamond electrode and a gas diffusion electrode (GDE) for generating highly oxidative species at both electrodes simultaneously. Such a system is not commercial available yet, which is mainly due to the absence of high efficient hydrogen peroxide generating gas diffusion electrodes working at greater current densities.
In addition to the challenging technical GDE design, the operating parameters strongly affect the electrochemical performance of H2O2-GDEs. While many published articles are screening electrodes under untechnical aspects with small Rotating-Ring-Disc-Electrode Systems [1, 2] or potential-controlled small scale electrolyzers [3, 4, 5], more technical-relevant scales under technical galvanostatic operation are missing.
Therefore, a technical-relevant scale of laboratory electrolysis with 100 square centimeters respectively was used, to evaluate the influence of process parameters to determine optimized operating points. The impact of current density, electrolytes pH-value, temperature (first results on the H2O2 concentration depending on temperature using 1 molar sodium hydroxide solution for a current density of 0.5 kA/m2 are presented in the diagram below) and O2 volume flow rate and the effect of the difference pressure were measured with respect to the H2O2-yield.
Finally, optimum process conditions for H2O2-producing GDE-evaluation are suggested.
References

J. F. Carneiro, R. S. Rocha, P. Hammer, R. Bertazzoli and M.R.V. Lanza, Applied Catalysis A: General,
517, 161–167 (2016).

W. R.P. Barros, R. M. Reis, R. S. Rocha and M. R.V. Lanza, Electrochimica Acta,
104, 12–18 (2013).

H. Luo, C. Li, C. Wu and X. Dong, RSC Adv,
5(80), 65227–65235 (2015).

R. S. Rocha, R. M. Reis, Beati, André A. G. F., M. R. V. Lanza, Sotomayor, Maria Del Pilar T. and R. Bertazzoli, Quím. Nova,
35(10), 1961–1966 (2012).

M. Panizza and G. Cerisola, Electrochimica Acta,
54(2), 876–878 (2008).

Figure 1