AFM-Assisted Investigation of the Corrosion Behaviour of Magnesium and AZ91 Alloys in an Ionic Liquid with Varying Water Content

2007 ◽  
Vol 60 (1) ◽  
pp. 35 ◽  
Author(s):  
Andrey Shkurankov ◽  
Sherif Zein El Abedin ◽  
Frank Endres
Keyword(s):  
Ionic Liquid ◽  
Corrosion Rate ◽  
Aqueous Solutions ◽  
Water Content ◽  
Corrosion Behaviour ◽  
Base Alloy ◽  
Saturated Calomel Electrode ◽  
Electrochemical Window ◽  
Metallic Impurities

Atomic force microscopy (AFM)-assisted corrosion measurements of poly- and microcrystalline magnesium, of AZ91D magnesium alloys, and of AZ91D alloys with defined amounts of metallic impurities (Cu, Ni, and Si) in the ionic liquid 1-butyl-3-methylimidazolium trifluoromethylsulfonate with variable water contents is reported. Whereas both magnesium and the AZ91 alloys show a tremendous corrosion in aqueous solutions, they are practically inert in the water-free ionic liquid. The apparent electrochemical window of the water-free ionic liquid on magnesium and its alloys can reach values of 10 V and more. The low corrosion rate of AZ91 alloys with metallic impurities, in any case, follows the trend in aqueous solutions: in comparison to the base alloy, the addition of nickel and silicon leads to higher corrosion rates. Upon addition of water to the ionic liquid two effects are observed. The higher the water content in the ionic liquid, the lower the corrosion potential and the higher the corrosion rate. Poly- and microcrystalline magnesium shows a surprisingly complicated corrosion behaviour, which gives rise to different processes during electrochemical polarization. As a proof-of-principle, in-situ AFM measurements were performed on the corrosion of AZ91D alloy in the ionic liquid. No corrosion products are observed at the surface in the water-free ionic liquid by in-situ AFM, even after several hours at +3 V versus a saturated calomel electrode (SCE), which indicates surface passivation in the ionic liquid.

scholarly journals Corrosion behaviour of an AlZnSnSrGa alloy in aqueous solutions of NaCl and Na2So4

2000 ◽  
Vol 65 (1) ◽  
pp. 73-81
Author(s):  
P. Zivkovic ◽  
J. Pjescic ◽  
S. Mentus
Keyword(s):  
Corrosion Rate ◽  
Aqueous Solutions ◽  
Polarization Resistance ◽  
Corrosion Current Density ◽  
Corrosion Behaviour ◽  
Base Material ◽  
Corrosion Current ◽  
Open Circuit ◽  
Base Metals ◽  
Aluminium Plant

The alloy composed of Al(95.53%), Zn(2.85%), Sn(0.515%), Ga(0.1%) and Sr(0.009%), with the weight percents in the parentheses, was prepared by melting, using Al(99.84%), a product of the Aluminium Plant-Podgorica, as the base material. The corrosion behaviour of this alloy was tested in relation to the behaviour of the base metals, by both open curcuit potential and polarization resistance methods, in aqueous solutions of both NaCl and Na2SO4, the concentration of which varied within the range 0.00051 - 0.51 mol dm -3. Over the whole salt concentration ranges, the corrosion parameters indicate that the corrosion rate of the alloy is significantly higher than the rate of the base material. For instance, for the concentration range 0.00051 - 0.51 mol dm -3 , the stationary open circuit potentials, related to SCE, in NaCl solutions were - 1.200 to - 1.460 V for the alloy and - 0.693 to - 0.920 V for Al, while in Na2SO4 solutions, the stationary open circuit potentials were - 1.190 to - 1.465V for the alloy and - 0.780 to - 0.860V for Al. At the same time, the corrosion current density in NaCl solutions varied within 11-89 mA cm -2 for the alloy and 0.35 - 0.80 for Al, while in Na2SO4 solutions it amounted to 5.7.52 mA cm -2 for the alloy and 0.28 - 0.88 mA cm -2 for Al.

The method of appearing solvent: Extraction of metal ions from aqueous solutions into in situ forming ionic liquid

2016 ◽  
Vol 469 (2) ◽  
pp. 238-240 ◽  
Author(s):  
S. V. Smirnova ◽  
T. O. Samarina ◽  
D. V. Il’in ◽  
I. V. Pletnev ◽  
Yu. A. Zolotov
Keyword(s):  
Ionic Liquid ◽  
Solvent Extraction ◽  
Aqueous Solutions ◽  
Metal Ions ◽  
In Situ Forming

scholarly journals The Effect of Water on the Tin Electrodeposition from [Bmim]HSO4 Ionic Liquid

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Jie Tang ◽  
DongLiang Lv ◽  
CunYing Xu ◽  
YiXin Hua ◽  
QiBo Zhang ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Water Content ◽  
Reduction Potential ◽  
Deposition Potential ◽  
Liquid Electrolyte ◽  
Cathodic Potential ◽  
Ionic Liquid Electrolyte ◽  
Electrochemical Window ◽  
Xrd Phase Analysis ◽  
The Difference

The electrodeposition of tin from SnO in ionic liquid 1-butyl-3-methylimidazolium hydrogen sulfate ([Bmim]HSO4) in the presence of water at different cathodic potential was investigated. With the addition of water to [Bmim]HSO4ionic liquid, the electrochemical window of the electrolyte decreases and the reduction potential of Sn(II) positively shifts. The water content of ionic liquid electrolyte has a distinct effect on morphology of the deposits. As water content increased from 0 to 50% (v/v), the morphology of deposits varies from granular to hexagonal rod-like, then to hollow tubular, and finally to wire-like. The XRD phase analysis showed that both Sn and CuSn alloys were deposited in ionic liquid/water mixtures. However, in dried ionic liquids only Cu3Sn was obtained, surprisingly. The difference in the structure might be attributed to the various interactions of the ions with the Cu substrate. In addition, the deposition potential was found to play a significant role in the morphology of deposits.

scholarly journals In Situ Formation of Ionic Liquid by Metathesis Reaction for the Rapid Removal of Bisphenol A from Aqueous Solutions

Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2087 ◽  
Author(s):  
Yesica Vicente-Martínez ◽  
Manuel Caravaca ◽  
Antonio Soto-Meca ◽  
Óscar De Francisco-Ortíz ◽  
Carmen Fernández-López
Keyword(s):  
Ionic Liquid ◽  
Bisphenol A ◽  
Aqueous Solutions ◽  
High Performance ◽  
Cost Effective ◽  
Metathesis Reaction ◽  
Experimental Conditions ◽  
Easy Method ◽  
Dispersive Liquid Liquid Microextraction

In this work we present a rapid and easy method to remove the totality of bisphenol A from aqueous solutions using ionic liquid (IL). Dispersive liquid–liquid microextraction is employed. The IL 1-octyl-3-methylimidazolium bis((trifluoromethane)sulfonyl)imide ([C8C1im] [NTf2]) is formed in situ because of the mixture of 1-octyl-3-methylimidazolium chloride ([C8C1im]Cl) and lithium bis(trifluoromethanesulfonyl)imide (Li[NTf2]) aqueous solutions. A cloud of microdroplets of IL formed by the dispersion generated through the precursors metathesis reaction allows the rapid and total extraction of bisphenol A (BPA). After centrifugation, the formed IL phase is deposited at the bottom of the flask and the total amount of BPA is extracted in the sedimented phase. The volume of IL is very low, in the order of microliters, which enables us to remove all the BPA from the solution. The technique studied is highly efficient, cost-effective, and presents less environmental impact than other extraction techniques, thus becoming an outstanding alternative to the most commonly used methods. BPA concentration is determined by high performance liquid chromatography by injecting the IL phase directly. An extraction kinetic model for the kinetic profile has been tested for this method, which allows to infer the ideal experimental conditions to execute the extraction method.

Electron microscopy using ionic liquids for life and materials sciences

Microscopy ◽  
2020 ◽  
Vol 69 (4) ◽  
pp. 183-195
Author(s):  
Tetsuya Tsuda ◽  
Susumu Kuwabata
Keyword(s):  
Electron Microscopy ◽  
Ionic Liquid ◽  
Ionic Liquids ◽  
Room Temperature ◽  
Life Science ◽  
Materials Science ◽  
Flame Resistance ◽  
Electrochemical Window ◽  
Microscopy Techniques

Abstract An ionic liquid (IL) is a salt consisting of only cations and anions, which exists in the liquid state at room temperature. Interestingly ILs combine various favorable physicochemical properties, such as negligible vapor pressure, flame resistance, relatively high ionic conductivity, wide electrochemical window, etc. To take advantage of two specific features of ILs, viz. their nonvolatile and antistatic nature, in 2006, Kuwabata, Torimoto et al. reported a milestone study led to current IL-based electron microscopy techniques. Thereafter, several IL-based electron microscopy techniques have been proposed for life science and materials science applications, e.g. pretreatment of hydrous and/or non-electron conductive specimens and in situ/operando observation of chemical reactions occurring in ILs. In this review, the fundamental approaches for making full use of these techniques and their impact on science and technology are introduced.

Corrosion and Protection of Friction Stir Welds

2006 ◽  
Vol 519-521 ◽  
pp. 699-704 ◽  
Author(s):  
Alison J. Davenport ◽  
Manthana Jariyaboon ◽  
Cristiano Padovani ◽  
Napachat Tareelap ◽  
Brian J. Connolly ◽  
...  
Keyword(s):  
Corrosion Behaviour ◽  
Base Alloy ◽  
Processing Parameters ◽  
Substantial Improvement ◽  
Friction Stir ◽  
Dissimilar Weld ◽  
Different Temperatures ◽  
Corrosion Susceptibility ◽  
Rapidly Solidified

The corrosion susceptibility of friction stir welds in AA2024-T351 was found to vary with the weld processing parameters. Corrosion attack was investigated with in situ X-ray tomography, which showed how the penetration of corrosion into the interior of the structure varied with weld microstructure. The susceptibility to corrosion was related to the degree of overageing by comparing the corrosion behaviour to samples of the base alloy that had been aged at different temperatures. A systematic increase first in the anodic reactivity and then the cathodic reactivity of the overaged structures with temperature can be used to predict the location of the region of the weld with the highest susceptibility to corrosion. Similar investigations were made for a dissimilar weld between AA2024 and AA7010. Laser surface melting produces a thin homogeneous melted and rapidly solidified layer over the weld surface leading to a substantial improvement in corrosion resistance.

scholarly journals Selective Dehydration of Glucose into 5-Hydroxymethylfurfural by Ionic Liquid-ZrOCl2 in Isopropanol

Catalysts ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 467 ◽  
Author(s):  
Yubo Ma ◽  
Lei Wang ◽  
Hongyi Li ◽  
Tianfu Wang ◽  
Ronghui Zhang
Keyword(s):  
Ionic Liquid ◽  
Water Content ◽  
Reaction Rate ◽  
Dehydration Reaction ◽  
Intermediate Species ◽  
Reaction Conditions ◽  
Heterogeneous Catalytic ◽  
Heterogeneous Catalytic System ◽  
Endothermal Reaction

In this work, a heterogeneous catalytic system consisting of [HO2CMMIm]Cl and ZrOCl2 in isopropanol is demonstrated to be effective for 5-hydroxymethylfurfural (HMF) synthesis with glucose as the feedstock. Various reaction conditions for HMF synthesis by glucose dehydration were investigated systematically. Under optimized reaction conditions, as high as 43 mol% HMF yield could be achieved. Increasing the water content to a level below 3.17% led to the production of HMF with a higher yield, while a lower HMF yield was observed when the water content was increased above 3.17%. In addition, the data also showed that ZrOCl2 could not only effectively convert glucose into intermediate species (which were not fructose, in contrast to the literature) but also catalyze the intermediate species’ in situ dehydration into HMF. [HO2CMMIm]Cl was used to catalyze the intermediate species’ in situ conversion to HMF. The kinetics data showed that a temperature increase accelerated the intermediate species’ dehydration reaction rate. The reaction of glucose dehydration was a strong endothermal reaction.

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