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  • 51. Femenia, M.
    et al.
    Canalias, C.
    Pan, Jinshan
    KTH, Tidigare Institutioner                               , Materialvetenskap.
    Leygraf, Christofer
    KTH, Tidigare Institutioner                               , Materialvetenskap.
    Scanning Kelvin probe force microscopy and magnetic force microscopy for characterization of duplex stainless steels2003Ingår i: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 150, nr 6, s. B274-B281Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this study, the Volta potential distribution over the surface of duplex stainless steels (DSSs) has been mapped for the first time with submicrometer resolution by scanning Kelvin probe force microscopy (SKPFM). The different magnetic properties of ferrite and austenite enable the utilization of magnetic force microscopy (MFM) for visualizing their surface distribution without the need of surface etching. The combined MFM and SKPFM mapping of the same area makes it possible to associate the variation in the Volta potential to the phase distribution and phase boundaries. The difference in potential between the two phases is measurable and significant. Generally, the ferrite phase was associated to regions of lower potential, and the austenite phase to regions of more noble potential. This can be regarded as direct evidence of galvanic interactions between the two phases. The phase boundary regions often exhibited a lower potential in the ferrite phase, indicating a higher tendency to corrosion. The high lateral resolution of SKPFM provides the possibility of comparing these results with those obtained from other localized techniques, a necessary step for a deeper understanding of the local corrosion processes in DSSs.

  • 52. Femenia, M.
    et al.
    Pan, Jinshan
    KTH, Tidigare Institutioner                               , Materialvetenskap.
    Leygraf, Christofer
    KTH, Tidigare Institutioner                               , Materialvetenskap.
    In situ local dissolution of duplex stainless steels in 1 M H2SO4+1 M NaCl by electrochemical scanning tunneling microscopy2002Ingår i: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 149, nr 6, s. B187-B197Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Local dissolution behavior of duplex stainless steel UNS S32304, UNS S31803, and UNS S32750 in 1 M H2SO4 + 1 M NaCl was studied in situ by electrochemical scanning tunneling microscopy (STM). Submicrometer features could be resolved and events occurring at phase/grain boundary regions could be monitored in the solution. By STM imaging, severe local dissolution was observed on UNS S32304 in the form of both pitting-like dissolution occurring at the active potential region, and selective dissolution of ferrite phase that already started at the corrosion potential. On UNS S31803, no pitting-like corrosion was observed, but a small amount of selective dissolution occurred at anodic potentials in the active region. The phase boundary region seemed to be prone to local dissolution. No noticeable local dissolution was observed on UNS S32750 in this solution in active and passive potential regions. The results show that a sufficient amount of both Mo and N in duplex stainless steel resulted in more homogeneous dissolution of the two phases and strengthened phase boundaries, and thus decreased the risk for local dissolution.

  • 53. Femenia, M.
    et al.
    Pan, Jinshan
    KTH, Tidigare Institutioner                               , Materialvetenskap.
    Leygraf, Christofer
    KTH, Tidigare Institutioner                               , Materialvetenskap.
    Luukkonen, P.
    In situ study of selective dissolution of duplex stainless steel 2205 by electrochemical scanning tunnelling microscopy2001Ingår i: Corrosion Science, ISSN 0010-938X, E-ISSN 1879-0496, Vol. 43, nr 10, s. 1939-1951Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Selective dissolution of duplex stainless steel 2205 in acidic chloride solutions was studied in situ by electrochemical scanning tunnelling microscopy (STM). In 0.05 M H2SO4 + 1 M NaCl, no appreciable active dissolution was observed by in situ STM imaging at the corrosion potential (E-corr), but at potentials higher than E-corr + 1000 mV some selective dissolution at the austenite-ferrite boundary region occurred. In 4 M H2SO4 + 1 M HCl, STM images revealed active dissolution of ferrite grains at around E-corr + 50 mV. Dissolution of austenite grains started to occur at around E-corr + 150 mV, exhibiting steps of submicron scale on the edges.

  • 54.
    Femenia, Marc
    et al.
    KTH, Tidigare Institutioner, Materialvetenskap.
    Pan, Jinshan
    KTH, Tidigare Institutioner, Materialvetenskap.
    Leygraf, Christofer
    KTH, Tidigare Institutioner, Materialvetenskap.
    Characterization of ferrite-austenite boundary region of duplex stainless steels by SAES2004Ingår i: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 151, nr 11, s. B581-B585Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Scanning Auger electron spectroscopy (SAES) has been used to investigate the phase boundary region between ferrite and austenite in three duplex stainless steels. Of the elements investigated Cr and Mo are partitioned to the ferrite phase, while Ni and N are partitioned to the austenite phase. The composition gradient across the phase boundary occurs within a few micrometers. The results are in accordance with previous results of the same phase boundary region obtained with complementary techniques. They form evidence of galvanic interaction between the ferrite and austenite phases and suggest this to be the main cause of the higher initial dissolution rate of ferrite adjacent to the austenite phase. The addition of alloying elements improves corrosion resistance of both the ferrite and austenite phases, the weaker sites are comparatively more strengthened. In the highly alloyed duplex stainless steel, the alloying elements are also partitioned, but in such a way that the corrosion resistance of the two phases is very similar, which results in a homogeneous dissolution behavior.

  • 55.
    Femenia, Marc
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Pan, Jinshan
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Leygraf, Christofer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Corrosion Studies of Duplex Stainless Steels with Micrometer Resolution2004Ingår i: Journal of Corrosion Science & Engineering, ISSN 1466-8858, E-ISSN 1466-8858, Vol. 6, s. paper 28-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The local corrosion behavior of duplex stainless steel (DSS) is affected by a wide variety of factors. Localized corrosion of DSS frequently starts at micrometer scale inclusions or precipitates, which are often segregated in the austenite-ferrite boundary regions. Moreover, due to the partitioning of the key alloying elements of ferrite (Cr and Mo) and austenite (N and Ni), the local interactions between the phases must also be considered. The aim of this doctoral study was to increase the knowledge about the local dissolution behavior of DSS in acidic-chloride environments. The recent developments of new local probing techniques have opened a new frontier in corrosion science, providing valuable local information not accessible in the past. The local techniques used include electrochemical scanning tunneling microscopy (EC-STM), scanning probe force microscopy (SKPFM), magnetic force microscopy (MFM), and scanning Auger electron Spectroscopy (SAES), all with micrometer or sub-micrometer resolution. With EC-STM, it was possible to monitor local dissolution processes on DSS in situ, and in real time. MFM was capable of imaging the phase distribution in DSS without the need of the traditional surface etching, while SKPFM revealed that the Volta potential difference between the two phases was measurable and significant. SAES showed that the composition gradient at the phase boundaries is narrower than 2 µm. Different types of DSSs have been studied, from low-alloyed DSS to superduplex. Higher contents of Cr, Mo and N strengthened both phases as well as the phase boundaries, resulting in phases having similar corrosion resistance that showed a more uniform dissolution behavior. However, the Volta potential difference between the phases proved to be of the same order for all the DSSs studied. Austenite was in general associated to regions displaying a more noble Volta potential than ferrite, resulting in a higher dissolution rate of the ferrite next to the austenite phase.

  • 56. Forsberg, J.
    et al.
    Duda, L. C.
    Olsson, A.
    Schmitt, T.
    Andersson, J.
    Nordgren, J.
    Hedberg, J.
    Leygraf, Christofer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Aastrup, T.
    Wallinder, D.
    Guo, J. H.
    System for in situ studies of atmospheric corrosion of metal films using soft x-ray spectroscopy and quartz crystal microbalance2007Ingår i: Review of Scientific Instruments, ISSN 0034-6748, E-ISSN 1089-7623, Vol. 78, nr 8Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We present a versatile chamber (atmospheric corrosion cell) for soft x-ray absorption/emission spectroscopy of metal surfaces in a corrosive atmosphere allowing novel in situ electronic structure studies. Synchrotron x rays passing through a thin window separating the corrosion cell interior from a beamline vacuum chamber probe a metal film deposited on a quartz crystal microbalance (QCM) or on the inside of the window. We present some initial results on chloride induced corrosion of iron surfaces in humidified synthetic air. By simultaneous recording of QCM signal and soft x-ray emission from the corroding sample, correlation between mass changes and variations in spectral features is facilitated.

  • 57. Forsberg, J.
    et al.
    Hedberg, Jonas
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Leygraf, Christofer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Nordgren, J.
    Duda, L. C.
    The Initial Stages of Atmospheric Corrosion of Iron in a Saline Environment Studied with Time-Resolved In Situ X-Ray Transmission Microscopy2010Ingår i: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 157, nr 3, s. C110-C115Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We have investigated atmospheric corrosion of a 50 nm layer of iron covered with a thin layer of NaCl by in situ X-ray transmission spectromicroscopy. We find that upon its deliquescence, a small part of the NaCl layer is rapidly transformed into a sodium oxide (NaOH) species. A large part of the sodium and chlorine ions forms a concentrated solution on the iron surface and becomes segregated, whereby the sodium ions appear stationary and passive during further corrosion progression. In contrast, the chlorine ions appear highly mobile and become concentrated at and travel with the corrosion front, apparently acting as a corrosion catalyst. The corrosion front progression is partly of filiform and partly of radial type. The early iron corrosion products (chloride-containing oxyhydroxides) are short-lived (for some hours) and undergo a transformation as the corrosion front sweeps by from a chlorinated species to a less chlorinated species.

  • 58.
    Forslund, Mattias
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Leygraf, Christofer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Claesson, Per M.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Pan, Jinshan
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Octadecanethiol as Corrosion Inhibitor for Zinc and Patterned Zinc-Copper in Humidified Air with Formic Acid2014Ingår i: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 161, nr 6, s. C330-C338Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The corrosion inhibition efficiency of octadecanethiol (ODT) for zinc and a zinc-copper patterned model sample (Zn-Cu) has been explored during exposure in an atmosphere that mimics indoor atmospheric corrosion containing humidified air (80% relative humidity at 20 degrees C) and formic acid (around 100 ppb). The corrosion kinetics were monitored in situ with infrared reflection absorption spectroscopy, and the local nature of corrosion effects post-analyzed with complementary scanning electron microscopy, atomic force microscopy and confocal Raman spectroscopy. ODT shows initially a corrosion inhibiting ability both on zinc and on Zn-Cu. This ability decreases with time due to local removal of ODT, which causes micro-galvanic effects that eventually result in corrosion rates that exceed those for the uncovered samples. On bare and ODT-covered samples, the presence of a copper-zinc junction results in both accelerated corrosion and in structurally more developed corrosion products. Overall, the results suggest that ODT can function as a temporary corrosion inhibitor in representative indoor environments on zinc and zinc with zinc-copper junctions.

  • 59.
    Forslund, Mattias
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Leygraf, Christofer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Claesson, Per Martin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Lin, C.
    Pan, Jinshan
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Micro-galvanic corrosion effects on patterned copper-zinc samples during exposure in humidified air containing formic acid2013Ingår i: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 160, nr 9, s. C423-C431Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Corrosion in indoor atmospheric environments is often triggered by carboxylic acids, especially at higher relative humidity. Microgalvanic effects can lead to severe corrosion, particularly important in miniature devices with small-sized metallic components. To elucidate the mechanism of micro-galvanic corrosion effects, well-defined zinc-copper patterned samples were investigated during exposure to 100 ppb formic acid (HCOOH) and 80% relative humidity at 20°C. The corrosion effects were monitored quantitatively with in situ infrared absorption spectroscopy, and the corrosion products characterized with scanning electron microscopy, confocal Raman microscopy, and atomic force microscopy. The nature of corrosion on zinc on the patterned samples was compared with that on pure zinc and turned out to result, not only in several times higher corrosion kinetics, but also in different corrosion products with respect to distribution, morphology, and composition. Local electrochemical and chemical gradients across the copper-zinc borders resulted in characteristic hemispherically shaped corrosion products at the zinc-copper junction, and in the formation of zinc formate dihydrate (Zn(HCOO)2 · 2H 2O) and crystalline zinc oxide (ZnO), phases not identified on pure zinc. In all, the micro-galvanic effects on the patterned samples resulted in accelerated corrosion kinetics and in structurally more developed corrosion products.

  • 60.
    Forslund, Mattias
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Leygraf, Christofer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Lin, Changjian
    Pan, Jinshan
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Radial Spreading of Localized Corrosion-Induced Selective Leaching on alpha-Brass in Dilute NaCl Solution2013Ingår i: Corrosion, ISSN 0010-9312, E-ISSN 1938-159X, Vol. 69, nr 5, s. 468-476Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The radial spreading of selective leaching on an a-brass alloy, Cu20Zn, in diluted sodium chloride (NaCl) has been followed in situ by light optical microscopy. The corrosion process initiates through localized dissolution of micrometer-sized, Zn-rich areas. These areas initially act as anodes, where the Zn will dissolve as Zn2+. The continued growth is a highly dynamic process, involving dezincification that results in local ennoblement of initial anode areas and changes in the local chemistry of the solution. These changes drive the anodic area outward to form a ring-shaped anode with an increasing diameter. At a sufficiently high local Cl- ion concentration, Cu dissolves as CuCl2-, whereby the radial growth continues. At critical minimum local Cl- ion concentration, the radial growth is terminated.

  • 61.
    Forslund, Mattias
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Pan, Jinshan
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Hosseinpour, Saman
    Zhang, Fan
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Johnson, Magnus
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Claesson, Per
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Leygraf, Christofer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Corrosion Inhibition of Two Brass Alloys by Octadecanethiol in Humidified Air with Formic Acid2015Ingår i: Corrosion, ISSN 0010-9312, E-ISSN 1938-159X, Vol. 71, nr 7, s. 908-917Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Self-assembled monolayers of octadecanethiol (ODT) have previously shown to provide excellent corrosion inhibition on copper exposed to humidified air containing formic acid, mimicking indoor atmospheric corrosion. ODT layers are, however, much less efficient corrosion inhibitors for zinc. In this work, we elucidate the possibility of using ODT monolayers to inhibit corrosion of brass. Based on a quantitative analysis of corrosion products, we found that ODT provides equally good corrosion inhibition of single-phase Cu20Zn as of pure copper, retarding the transportation of corrosion stimulators to the brass surface. On double-phase Cu40Zn, however, local galvanic effects led to less efficient corrosion inhibition and more corrosion products than on Cu20Zn.

  • 62.
    Forslund, Mattias
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Pan, Jinshan
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Hosseinpour, Saman
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Zhang, Fan
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Johnson, Magnus
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Claesson, Per
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Leygraf, Christofer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    The atmospheric corrosion inhibition of octadecanethiol adsorbed on two brass alloys exposed to humidified air with formic acidManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Self-assembled monolayers of octadecanethiol (ODT) have previously shown to provide excellent corrosion inhibition on copper exposed to humidified air containing formic acid - mimicking indoor atmospheric corrosion. ODT layers are, however, much less efficient corrosion inhibitors for zinc. In this work we elucidate the possibility of using ODT monolayers to inhibit corrosion of brass. We find that ODT provides equally good corrosion inhibition of single-phase Cu20Zn as of pure copper, retarding the transport of corrosion stimulators to the brass surface. On double-phase Cu40Zn, however, local galvanic effects lead to less efficient corrosion inhibition and more corrosion products than on Cu20Zn.

  • 63.
    Gil, Harveth
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Leygraf, Christofer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Quantitative in situ analysis of initial atmospheric corrosion of copper induced by acetic acid.2007Ingår i: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 154, nr 5, s. 272-278Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The initial atmospheric corrosion of copper was investigated by means of a quantitative in situ analysis in an atmospherecontaining 120 ppb of acetic acid and 95% relative humidity using a quartz crystal microbalance (QCM) integrated with infraredreflection absorption spectroscopy (IRAS). Crystalline cuprous oxide (various structural forms of Cu2O) and hydrated copperacetate were detected as corrosion products during up to 100 h of exposure. The quantification of data was made possible throughan observed linear relationship between the absorbance of vibrations (IRAS)of both phases and the corresponding mass (QCM).The quantification of cuprous oxide was further supported by ex situ coulometric reduction of the corrosion products. The growthrate of cuprous oxide was initially very fast but almost zero after 20 h exposure where it reached an average thickness of13 ± 1 nm. Copper acetate exhibited a more constant growth rate. Atomic force microscopy showed a uniform growth of cuprousoxide with surface roughness that increased with time and localized formation of copper acetate. The quantified data are consistentwith a previously proposed model that involves proton- and acetate-induced dissolution of copper and subsequent precipitation ofcuprous oxide and copper acetate.

  • 64.
    Gil, Harveth
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Leygraf, Christofer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Tidblad, Johan
    GILDES Model Simulations of the Atmospheric Corrosion of Copper Induced by Low Concentrations of Carboxylic Acids2011Ingår i: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 158, nr 12, s. C429-C438Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A computer simulation with a GILDES-based model using the COMSOL multiphysics software was performed for copper exposedto low concentrations of carboxylic acids in humidified air at room temperature. GILDES is a six-regime computer model (Gas,the Interface between gas and liquid, the Liquid, the Deposition layer, the Electrodic region near the surface and the Solid). Thesimulations were compared to previously published in-situ results for copper at the same conditions analysed by a quartz crystalmicrobalance (QCM) and infrared reflection absorption spectroscopy (IRAS). Experimental and calculated results agree with eachother with respect to the effect of corrosion, showing formic acid as the most aggressive followed by acetic and propionic acid.This is supported by a higher ligand- and proton-promoted dissolution found in formic acid exposures, followed by acetic andpropionic exposures. The dominating precipitated phases were Cu2O, Cu(OH)2, Cu(CH3COO)2 · H2O, Cu(HCOO)2 · 4H2O andCu(CH3CH2COO)2 · H2O. Besides Cu2O, the simulations suggest that the hydrated form of the respective carboxylates is the mostlikely compound to be formed in this type of atmospheres.

  • 65.
    Gil, Harveth
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Leygraf, Christofer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Tidblad, Johan
    Swerea Kimab.
    GILDES model simulations of the atmospheric corrosion of zinc induced by low concentrations of carboxylic acids2012Ingår i: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 159, nr 3, s. C123-C128Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The GILDES computer based model was successfully applied to the atmospheric corrosion of zinc exposed to low concentrations of carboxylic acids in humidified air at room temperature. Under these exposure conditions the expected precipitated phases are zinc oxide (ZnO), zinc hydroxide (Zn(OH)(2)) and several forms of hydrated zinc carboxylate, Zn(CH3CH2COO)(2) center dot 2H(2)O, Zn(CH3COO)(2) center dot 2H(2)O and Zn(HCOO)(2) center dot 2H(2)O. The results were compared to those from laboratory exposures obtained in the same conditions. The model correctly predicts the trend for ZnO and zinc carboxylate formation found in experimental exposures for the three acids tested. According to the simulations, surface protonation, surface acid base reactions, as well as ligand- and proton-induced dissolution reactions play a major role in the initial atmospheric corrosion of zinc. Henry's law constant (K-H) is found to be an important parameter but uncertain due to different reported literature values. When K-H is increased the formation rate of zinc carboxylate also increases. K-H increases in the sequence propionic acid < acetic acid < formic acid, the same order as found for the calculated dissolution rate.

  • 66.
    Gil, Harveth
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Leygraf, Christopher
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Initial atmospheric corrosion of copper induced by carboxylic acids2007Ingår i: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 154, nr 11, s. C611-C617Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A procedure based on infrared reflection absorption spectroscopy integrated with a quartz crystal microbalance has been developed and used for comparison of initial atmospheric corrosion of copper induced by formic, acetic, and propionic acid. The absolute mass of individual constituents of corrosion products formed, mainly cuprous oxide or cuprite, copper carboxylate, and water or hydroxyl groups, could be obtained under in situ conditions during exposure in 120 ppb of carboxylic acid concentration, 95% relative humidity, 20 degrees C, and up to 96 h of exposure. The quantitative data exhibit consistency between all acids and with postanalysis performed by coulometric reduction. Two spatially separated main pathways have been identified: a proton-induced dissolution of cuprous ions followed by the formation of copper(I) oxide, and a carboxylate-induced dissolution followed by the formation of copper(II) carboxylate. The first pathway is initially very fast but levels off, grows more uniformly over the surface, and dominates in acetic acid. The second pathway exhibits a more constant growth rate and localized growth, and dominates in formic acid. Propionic acid exhibits low rates for both pathways. The difference between the carboxylic acids with respect to both total corrosion rate and carboxylate-induced dissolution can be attributed to their dissociation constants and deposition velocity.

  • 67.
    Goidanich, Sara
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Wallinder, Inger Odnevall
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Herting, Gunilla
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Leygraf, Christofer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Corrosion induced metal release from copper based alloys compared to their pure elements2008Ingår i: Corrosion Engineering, Science and Technology, ISSN 1478-422X, E-ISSN 1743-2782, Vol. 43, nr 2, s. 134-141Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Despite numerous studies on atmospheric corrosion of copper and copper based alloys, the corrosion induced release processes of individual alloy constituents suffer from significant knowledge gaps. This investigation comprises metal release rate measurements of copper, zinc and tin from some copper based alloys including brass (20 wt-% Zn) and bronze (6 wt-% Sn), and their pure alloying metals, copper, zinc and tin. Data have been generated during a 2.5 year urban field exposure in Stockholm, Sweden and parallel laboratory investigations in a specially designed rain chamber using artificial rain. Brass shows significantly lower annual release rates of both copper and zinc compared to pure metal sheets of its alloy constituents. Zinc is preferentially released compared to copper. Dezincification of brass occurs both at field and laboratory conditions, a process influenced by rain characteristics. Alloying with tin does not largely reduce the release rate of copper from bronze compared to pure copper. No measurable amount of tin is released from the bronze surface.

  • 68. Graedel, T. E.
    et al.
    Leygraf, Christofer
    KTH, Tidigare Institutioner                               , Materialvetenskap.
    Corrosion mechanisms for nickel exposed to the atmosphere2000Ingår i: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 147, nr 3, s. 1010-1014Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Physical and chemical information on nickel corrosion layer formation, evolution, morphology, and chemical makeup is organized and presented, together with information on nickel-containing minerals and other crystalline structures that might be expected to be present. The chemical reactions involved in the formation of these constituents during the corrosion process are then surveyed. By far the most abundant of the typical corrosion products are various forms of nickel sulfates, including hydroxysulfates and the mineral retgersite (alpha-NiSO4. 6H(2)O). The presence of these species is shown to be a natural consequence of the thin aqueous layer chemistry involving atmospheric SO2 and SO42- that occurs on nickel in humid environments. Formation pathways for retgersite and gaspeite are shown in schematic diagrams. Comprehensive kinetic simulations of the corrosion processes have begun to provide insight into the corrosion chemistry but-are limited by a shortage of laboratory determinations of the rates of dissolution, precipitation, and transformation of nickel-containing chemical species.

  • 69.
    Halldin Stenlid, Joakim
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Tillämpad fysikalisk kemi.
    Johansson, Adam Johannes
    Leygraf, Christopher
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Brinck, Tore
    KTH, Skolan för kemivetenskap (CHE), Kemi, Tillämpad fysikalisk kemi.
    Computational Analysis of the Early Stage of Cuprous Oxide Sulphidation: A Top-Down Process2017Ingår i: Corrosion Engineering, Science and Technology, ISSN 1478-422X, E-ISSN 1743-2782, Vol. 52, nr S1, s. 50-53Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The initial steps of Cu2O sulphidation to Cu2S have been studied using plane-wave density functional theory at the PBE-D3+U level of sophistication. Surface adsorption and dissociation of H2S and H2O, as well as the replacement reaction of lattice oxygen with sulphur, have been investigated for the most stable (111) and (100) surface facets under oxygen-lean conditions. We find that the (100) surface is more susceptible to sulphidation than the (111) surface, promoting both H2S adsorption, dissociation and the continued oxygen–sulphur replacement. The results presented in this proceeding bridge previous results from high-vacuum experiments on ideal surface to more realistic corrosion conditions and set the grounds for future mechanistic studies. Potential implications on the long-term final disposal of spent nuclear fuel are discussed.

  • 70.
    Halldin Stenlid, Joakim
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Tillämpad fysikalisk kemi.
    Soldemo, Markus
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik, Materialfysik, MF.
    Johansson, A. J.
    Leygraf, Christofer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Götelid, Mats
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik, Materialfysik, MF.
    Weissenrieder, Jonas
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik, Materialfysik, MF.
    Brinck, Tore
    KTH, Skolan för kemivetenskap (CHE), Kemi, Tillämpad fysikalisk kemi.
    Reactivity at the Cu2O(100):Cu-H2O interface: a combined DFT and PES study2016Ingår i: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 18, nr 44, s. 30570-30584Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The water-cuprite interface plays an important role in dictating surface related properties. This not only applies to the oxide, but also to metallic copper, which is covered by an oxide film under typical operational conditions. In order to extend the currently scarce knowledge of the details of the water-oxide interplay, water interactions and reactions on a common Cu2O(100):Cu surface have been studied using high-resolution photoelectron spectroscopy (PES) as well as Hubbard U and dispersion corrected density functional theory (PBE-D3+U) calculations up to a bilayer water coverage. The PBE-D3+U results are compared with PBE, PBE-D3 and hybrid HSE06-D3 calculation results. Both computational and experimental results support a thermodynamically favored, and H2O coverage independent, surface OH coverage of 0.25-0.5 ML, which is larger than the previously reported value. The computations indicate that the results are consistent also for ambient temperatures under wet/humid and oxygen lean conditions. In addition, both DFT and PES results indicate that the initial (3,0; 1,1) surface reconstruction is lifted upon water adsorption to form an unreconstructed (1 x 1) Cu2O(100) structure.

  • 71. He, W.
    et al.
    Odnevall Wallinder, Inger
    KTH, Tidigare Institutioner                               , Materialvetenskap.
    Leygraf, Christofer
    KTH, Tidigare Institutioner                               , Materialvetenskap.
    A laboratory study of copper and zinc runoff during first flush and steady-state conditions2001Ingår i: Corrosion Science, ISSN 0010-938X, E-ISSN 1879-0496, Vol. 43, nr 1, s. 127-146Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The influence of environmental conditions and corrosion layer characteristics have been investigated on the runoff rate of copper and zinc, used as roofing material. For this purpose, a rain device has been constructed, capable of simulating rain episodes of varying intensity and pH, and used on new and aged copper and zinc panels of varying origin and corrosion product composition. The setup, using artificial rain with a composition resembling the southern and central part of Sweden, has proven to result in realistic runoff rates for all materials investigated. During a rain event, easily soluble corrosion products will be removed in the first rain volume, commonly referred to as the first flush, followed by a more or less constant runoff rate during subsequent rain. The magnitude of the first flush depends on environmental conditions prior Co a rain episode, e.g., length of dry periods and extent of dry deposition, as well as on rain volume and rain intensity. A defect-rich and porous corrosion layer increases the magnitude of the first flush. The total metal runoff quantity increases with decreasing pH for both copper and zinc. In agreement with previous findings outdoors, an effect of patina age can be seen on copper. The laboratory data can be used to explain variations in runoff rate between different sampling periods observed in field data.

  • 72. He, W
    et al.
    Odnevall Wallinder, Inger
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Leygraf, Christofer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Runoff Rates of Zinc - a Four-Year Field and Laboratory Study: American Society for Testing and Materials2002Ingår i: Outdoor Atmospheric Corrosion / [ed] Herbert E Townsend, ASTM International, 2002, s. 216-Kapitel i bok, del av antologi (Refereegranskat)
  • 73.
    Hedberg, Jonas
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Baldelli, Steven
    Department of Chemistry, University of Houston.
    Leygraf, Christofer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Evidence for the Molecular Basis of Corrosion of Zinc Induced by Formic Acid using Sum Frequency Generation Spectroscopy2010Ingår i: Journal of Physical Chemistry Letters, ISSN 1948-7185, Vol. 1, nr 10, s. 1679-1682Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In situ observations of surface hydroxyl groups and the subsequent ligand exchange during initial atmospheric corrosion conditions of Zn are reported. The data have been obtained with sum frequency generation spectroscopy (SFG) during exposure of polycrystalline zinc to humidified or dry nitrogen gas, N-2, to which 100 parts per billion of formic acid, HCOOH, was added. The SFG data provide evidence of surface hydroxyl groups and their gradual replacement by formate species through a ligand exchange, representing the initial step of formate-induced dissolution of zinc. In addition, the aqueous adlayer on the Zn surface is probed, and the occurrence of the free OH vibration confirms a bulk-like water film.

  • 74.
    Hedberg, Jonas
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Baldelli, Steven
    Univ Houston, Dept Chem, Houston, TX 77204 USA.
    Leygraf, Christofer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära (stängd 20081231).
    Initial Atmospheric Corrosion of Zn: Influence of Humidity on the Adsorption of Formic Acid Studied by Vibrational Sum Frequency Spectroscopy2009Ingår i: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 113, s. 6169-6173Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The ZnO/Zn surface exposed to formic acid undergoes a partial, reversible dissociation to formate ion, and a protonated surface oxide and is seen to have different hydration states depending on the relative humidity. Under high relative humidity conditions it exists as a formate coordinated to the surface with the oxygen atoms toward the surface and the C-H directed away into the vapor. In a dry environment a formic acid/formate intermediate is formed, although a substantial amount of dissociated species still are present, in both hydrated and nonhydrated form. The results may have implications on the initial atmospheric corrosion of Zn and emphasize that the ZnO/Zn surface is heterogeneous with a range of acid and basic sites for the adsorption of formate and the proton.

  • 75.
    Hedberg, Jonas
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Baldelli, Steven
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Leygraf, Christofer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Molecular Structural Information of the Atmospheric Corrosion of Zinc Studied by Vibrational Spectroscopy Techniques II. Two and Three-Dimensional Growth of Reaction Products Induced by Formic and Acetic Acid2010Ingår i: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 157, nr 10, s. C363-C373Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In an effort to obtain a more molecular view of atmospheric corrosion, we present experimental data from three complementary acting vibrational spectroscopy techniques that have been used in parallel exposures to follow the initial atmospheric corrosion of zinc during exposure in dry or humid air to which formic acid or acetic acid was added, with the primary aim to simulate indoor exposure conditions. The techniques used were vibrational sum frequency spectroscopy (interface sensitive), IR reflection absorption spectroscopy (near-surface sensitive), and confocal Raman microspectroscopy (bulk sensitive with submicrometer surface lateral resolution). The growth of two-dimensional interface species of zinc formate or zinc acetate could be monitored in situ and distinguished from three-dimensional growth of ZnO and zinc hydroxy formate or acetate. These interface species are believed to act as precursors of the dissolution of aqueous zinc carboxylate species that subsequently deposit at the surface and result in local growth of crystalline or amorphous ZnO and local zinc hydroxy carboxylate. Differences in the growth of corrosion products induced by acetic or formic acid were mainly attributed to differences in pH of the aqueous adlayer and in different deposition velocities of the acids into the aqueous adlayer. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3479255] All rights reserved.

  • 76.
    Hedberg, Jonas
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Baldelli, Steven
    Leygraf, Christofer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Tyrode, Eric
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Molecular Structural Information of the Atmospheric Corrosion of Zinc Studied by Vibrational Spectroscopy Techniques I. Experimental Approach2010Ingår i: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 157, nr 10, s. C357-C362Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    As the nature of the interactions taking place on a metal surface during atmospheric corrosion is inherently complex, it imposes demands on the analytical studies that are needed to understand the fundamentals on a molecular level. Corrosion products may spread on the metal surface forming two-and three-dimensional structures. Thus, it is imperative to use different techniques to resolve the different types of growth. In this first part of a series of two papers, a systematic investigation is made to obtain detailed information on the mechanisms of the onset of atmospheric corrosion of zinc exposed to 115 ppb acetic acid in either dry or humidified air. The vibrational spectroscopy techniques used were vibrational sum frequency spectroscopy (VSFS, interface sensitive), infrared reflection absorption spectroscopy (IRAS, near-surface sensitive), and confocal Raman microspectroscopy (CRM, bulk sensitive). The VSFS selectively targeted the two-dimensional structures, IRAS followed the growth of three-dimensional corrosion products, and CRM could provide a laterally resolved chemical map on localized aggregates of zinc hydroxy acetate and ZnO with bulk character. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3479207] All rights reserved.

  • 77.
    Hedberg, Jonas F.
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära (stängd 20081231).
    Qiu, Ping
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära (stängd 20081231).
    Leygraf, Christofer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära (stängd 20081231).
    Vibrational sum frequency spectroscopy for in situ studies of initial atmospheric corrosion of zinc induced by formic acid2008Ingår i: Int. Corros. Congr.: Corros. Control Serv. Soc., 2008, s. 1536-1541Konferensbidrag (Refereegranskat)
    Abstract [en]

    With the access and recent development of interface sensitive analytical techniques, it has become possible to perform molecular in situ analyses of the interfaces involved under ambient atmospheric pressure conditions. The initial indoor atmospheric corrosion of zinc has been investigated by vibrational sum frequency spectroscopy (VSFS). Vibrational sum frequency spectroscopy is an inherent surface sensitive technique which also gives information on the ordering of the molecules. It is used herein for probing the interface between the metal and the spontaneously formed aqueous adlayer. The zinc was exposed to humidified air to which formic acid (HCOOH) was added as corrosion stimulant. VSFS showed evidence of formate on the surface after exposure to 120 ppb formic acid, and the structure of the surface formates were seen to stabilize within approximately 90 minutes of exposure. This is in contrast with near-surface probing Infra red reflection absorption spectroscopy (IRAS) results which monitors a continuous increase in zinc formates beyond 90 minutes of exposure to formic acid and humid air. These results form evidence that the structure of the surface formates stays the same beyond 90 minutes of exposure, even though there is an ongoing corrosion process, as seen by the growth of the thin film of formates.

  • 78.
    Hedberg, Jonas
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Leygraf, Christofer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Initial Atmospheric Corrosion of Zinc Exposed to Formic Acid, Investigated by in Situ Vibrational Sum Frequency Spectroscopy and Density Functional Theory Calculations2008Ingår i: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 113, s. 2088-2095Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Vibrational sum frequency spectroscopy (VSFS) and ab initio density functional theory (DFT) calculations of formic acid on ZnO/Zn have been performed in order to understand the first step of atmospheric corrosion on zinc initiated by formic acid. In addition, infrared reflection absorption spectroscopy (IRAS) has been employed to complement the surface sensitive VSFS results to identify the corrosion products. Oxidized polycrystalline zinc samples were exposed to 120 ppb formic acid in either humid or dry Air where, the formic acid adsorption on ZnO/Zn is observed to have a low dependence on the humidity, as deduced by VSFS. Formate is formed on the surface in both dry and humid air and stabilized in configuration after about 90 min exposure in 120 ppb formic acid as seen in the VSFS results. This is evidenced by the occurrence of the CH and symmetric COO- vibrations of the formate ion. The DFT calculations support the VSFS results, showing a coordination of the formate to zinc ions without participation from water molecules.

  • 79.
    Hedberg, Jonas
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Leygraf, Christofer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Molecular in-situ observations of hydroxyl groups and ligand exchange during initial atmospheric corrosionManuskript (preprint) (Övrigt vetenskapligt)
  • 80.
    Hedberg, Jonas
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Leygraf, Christofer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Molecular structural information of the atmospheric corrosion of zinc studied by vibrational spectroscopy techniques: Part I. Experimental approachManuskript (preprint) (Övrigt vetenskapligt)
  • 81.
    Hedberg, Jonas
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Leygraf, Christofer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Molecular structural information of the atmospheric corrosion of zinc studied by vibrational spectroscopy techniques: Part II. Two and three dimensional growth of reaction products induced by formic and acetic acidManuskript (preprint) (Övrigt vetenskapligt)
  • 82.
    Hedberg, Jonas
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Leygraf, Christofer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära (stängd 20081231).
    Cimatu, Katherine
    Baldelli, Steven
    Adsorption and Structure of Octadecanethiol on Zinc Surfaces As Probed by SumFrequency Generation Spectroscopy, Imaging, and Electrochemical Techniques2007Ingår i: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 111, nr 47, s. 17587-17596Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Octadecanethiol (ODT) adsorbed onto zinc has been studied with sum frequency generation (SFG), sum frequency generation imaging microscopy (SFG-IM), X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV), and electrical impedance spectroscopy (EIS) in order to investigate its corrosion protective ability and conformational ordering. SFG shows that ODT forms an ordered adsorbate on both reduced and oxidized zinc within short times after immersion in 1 mM ODT/ethanol solution. The corrosion protection, deduced by EIS, is also improved after immersion in the ODT solution. After longer immersion times, the corrosion protection decreases as well as the conformational order of the adsorbed ODT. Increasing the ODT concentration avoids this degradation with prolonged immersion time. The ODT is seen in the XPS spectra to adsorb to the reduced as well as the oxidized zinc by forming a Zn-S bond for both short and long immersion times. The SFG-IM completes the picture, showing a heterogeneous surface with areas corresponding to ordered ODT as well as disordered or uncovered regions. The density of adsorbed ODT after 24 h immersion time for both reduced and oxidized zinc was deduced from CV and was found to be approximately 6.7 x 10(-9) mol/cm(2).

  • 83. Heijerick, D. G.
    et al.
    Janssen, C. R.
    Karlen, C.
    Odnevall Wallinder, Inger
    KTH, Tidigare Institutioner                               , Materialvetenskap.
    Leygraf, Christofer
    KTH, Tidigare Institutioner                               , Materialvetenskap.
    Bioavailability of zinc in runoff water from roofing materials2002Ingår i: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 47, nr 10, s. 1073-1080Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Corrosion and runoff from zinc-coated materials and outdoor structures is an important source for the dispersion of zinc in the environment. Being part of a large inter-disciplinary research project, this study presents the bioavailability of zinc in runoff water immediately after release from the surface of 15 different commercially available zinc-based materials exposed to the urban environment of Stockholm, Sweden. Runoff water was analysed chemically and evaluated for its possible environmental impact, using both a biosensor test with the bacteria Alcaligenes eutrophus (Biomet(R)) and the conventional 72 h growth inhibition test with the green alga Raphidocelis subcapitata. Chemical speciation modelling revealed that most zinc (94.3-99.9%) was present as the free Zn ion, the most bioavailable speciation form. These findings were confirmed by the results of the biosensor test (Biomet(R)) which indicated that all zinc was indeed bioavailable. Analysis of the ecotoxicity data also suggested that the observed toxic effects were due to the presence of Zn2+ ions. Finally, regression analysis showed that, for this type of runoff samples, the rapid screening biosensor was capable of predicting (a) the total amount of zinc present in the runoff samples (R-2 of 0.93-0.98; p < 0.05) and (b) the observed 72 h-EbC(50)s (R-2 of 0.69-0.97; p < 0.05).

  • 84.
    Herting, Gunilla
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Goidanich, Sara
    Odnevall Wallinder, Inger
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära (stängd 20081231).
    Leygraf, Christofer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära (stängd 20081231).
    Corrosion-induced release of Cu and Zn into rainwater from brass, bronze and their pure metals. A 2-year field study2008Ingår i: Environmental Monitoring & Assessment, ISSN 0167-6369, E-ISSN 1573-2959, Vol. 144, nr 1-3, s. 455-461Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A 2-year field study has been conducted in an urban environment to provide annual release rates of copper and zinc from brass (20 wt% Zn) and copper and tin from bronze (6 wt% Sn) compared to sheets of their pure alloy constituents, copper and zinc. Despite relatively low nominal bulk alloy content, substantially more zinc was released from brass compared to copper. Both metals were released at a significantly slower rate from the brass alloy, compared to the pure metals. The proportion of release rates of copper and zinc from the alloy differed significantly from their proportions in the bulk alloy. Bronze showed relatively constant release rates of copper, being similar to that of pure copper sheet. The release of tin from bronze was negligible. The results clearly show that alloys and the pure metals behave very differently when exposed to rainwater. Accordingly, release rates from pure metals cannot be used to predict release rates of individual constituents from their alloys. Generated data are of importance within REACH, the new chemical policy of the European commission, where metal alloys erroneously are being treated as mixtures of chemical substances.

  • 85.
    Herting, Gunilla
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Leygraf, Christofer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Odnevall Wallinder, Inger
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Influence of Surface Finish on Stainless Steel AISI 304 on the Metal Release Process in Synthetic Biological Media2008Konferensbidrag (Refereegranskat)
    Abstract [en]

    The objective of this study is to illuminate differences in metal release rates between varioussurface finishes on stainless steel. A large range of finishes exist on the market, and varies depending onarea of application and aesthetic appearance. The influence of surface finish is examined andexemplified using stainless steel grade AISI 304 in terms of individual metal release rates of the mainalloying elements: chromium, nickel and iron using inductively coupled plasma-mass spectrometry,ICP-MS, differences in the electrochemically active surface area using electrochemical impedancespectroscopy, EIS, and changes in surface composition of the outermost surface oxide using x-rayphotoelectron spectroscopy, XPS. The study includes five different cold-rolled surface finishes, threecommercial surfaces, BA, 2B and 2D (as described in the Euronorm and ASTM specifications), oneelectropolished surface, and one electropolished and passivated surface, all separately immersed in asynthetic body fluid (artificial lysosomal fluid, pH 4.5), and sampled after 8 and 168 hours at 37 ºC.The electrochemically active surface area is found to have a significant influence on the total metalrelease rate, increasing as follows: electropolished and passivated < electropolished < BA ≈ 2B < 2D.

  • 86.
    Herting, Gunilla
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Lindström, David
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära (stängd 20081231).
    Odnevall Wallinder, Inger
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära (stängd 20081231).
    Leygraf, Christofer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära (stängd 20081231).
    Multi-analytical investigation of stainless steel grade AISI 420 in simulated food contact2009Ingår i: Journal of Food Engineering, ISSN 0260-8774, E-ISSN 1873-5770, Vol. 93, nr 1, s. 23-31Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Martensitic stainless steel grade AN 420 intended for cutlery knives and scissor blades has been investigated in all attempt to correlate microstructure and surface finish (polishing procedure) to metal release rates of the main alloy constituents, iron and chromium. Metallographic investigations proved the knife steel and, in particular the scissor steel to have very inhomogeneous microstructures. The knife steel contained bands of ferrite in the martensitic structure while the scissor steel revealed large amounts of tempered martensite and inclusions of manganese sulphides and silicon oxides. Samples of different surface finish were immersed in 3 vol% acetic acid at 40 degrees C from 1 to 10 days for metal release testing. simulating food contact. The largely inhomogeneous microstructure of the scissor steel results in high and greatly varying metal release rates. despite a fairly high chromium content Of the Surface oxide. Areas of inclusions seem to act as initiation points for accelerated metal release and the forming of a surface oxide depleted in chromium, but rich in copper. The generation Of high Surface temperatures during polishing was found beneficial from a metal release perspective as a result Of the formation of a surface oxide of improved passivating properties.

  • 87.
    Herting, Gunilla
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Odnevall Wallinder, Inger
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Leygraf, Christofer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    A comparison of release rates of Cr, Ni and Fe from stainless steel alloys and the pure metals exposed to simulated rain events2005Ingår i: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 152, nr 1, s. B23-B29Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The aim of this study is to demonstrate differences in metal release rates of Cr, Ni, and Fe from pure metals and stainless steels alloys (grades 304 and 316) exposed to identical simulated rain events. Panels were exposed to two 8 h continuous rain periods, separated by a 40 day dry period, in a specially designed rain chamber which permits artificial rain of known composition to be introduced at a given intensity. The study is intended to provide further knowledge of the behavior of stainless steels exposed to atmospheric corrosion and to show the discrepancy between estimated release rates based on nominal alloy composition and actual, measured release rates. Release rates of Fe and Ni were found to be substantially higher from the pure metals than from the stainless steels due to the presence of a chromium-rich surface film. The release rate of Cr was similar for stainless steel alloys and pure chromium. X-ray photoelectron spectroscopy investigations after single-rain events showed chromium to be enriched in the surface film upon rain exposure resulting in decreasing release rates of Cr, Ni, and Fe. Comparison between actual release rates of alloy constituents and calculated rates based on the pure metals and the nominal alloy composition, showed calculated data to substantially overestimate release rates of Ni and Fe.

  • 88.
    Herting, Gunilla
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Odnevall Wallinder, Inger
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Leygraf, Christofer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Corrosion-induced release of chromium and iron from ferritic stainless steel grade AISI 430 in simulated food contact2008Ingår i: Journal of Food Engineering, ISSN 0260-8774, E-ISSN 1873-5770, Vol. 87, nr 2, s. 291-300Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Ferritic stainless steel grade AISI 430 with three different surface finishes, glossy, line and abraded has been evaluated regarding changes in metal release rates and corresponding changes in surface composition when immersed in 3 vol% acetic acid at two different temperatures, 40 degrees C for ten days and 100 degrees C during three consecutive immersions of 30 min each. Test parameter intervals were set by one of the very few regulatory texts for metal release in food applications, the Italian law text D.M. 21-03-1973, Art. 37. The metal release process was found to be strongly dependent on surface area to solution volume ratio where a specific surface finish would be within the allowed limit, 0.1 mg Cr L-1 for the lowest ratio, 0.5 cm, but exceeded for the highest ratio, 2 cm(-1). The amount of released metal increased with increasing temperature and increasing surface roughness (surface finish).

    Generated data show the regulatory text insufficient and to provide large degrees of freedom, specifically in terms of defining the surface area to solution volume ratio and the acidic cleaning of test vessels, essential parameters to enable reproducible and relevant migration data.

  • 89.
    Herting, Gunilla
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Odnevall Wallinder, Inger
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Leygraf, Christofer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Corrosion-induced release of the main alloying constituents of manganese-chromium stainless steels in different media2008Ingår i: Journal of Environmental Monitoring, ISSN 1464-0325, E-ISSN 1464-0333, Vol. 10, nr 9, s. 1084-1091Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The main focus of this paper is the assessment of release rates of chromium, nickel, iron and manganese from manganese-chromium stainless steel grades of low nickel content. The manganese content varied between 9.7 and 1.5 wt% and the corresponding nickel content between 1 and 5 wt%. All grades were exposed to artificial rain and two were immersed in a synthetic body fluid of similar pH but of different composition and exposure conditions. Surface compositional studies were performed using X-ray photoelectron spectroscopy (XPS) in parallel to correlate the metal release process with changes in surface oxide properties.

    All grades, independent of media, revealed a time-dependent metal release process with a preferential low release of iron and manganese compared to nickel and chromium while the chromium content of the surface oxide increased slightly. Manganese was detected in the surface oxide of all grades, except the grade of the lowest manganese bulk content. No nickel was observed in the outermost surface oxide. Stainless steel grades of the lowest chromium content (approximate to 16 wt%) and highest manganese content (approximate to 7-9 wt%), released the highest quantity of alloy constituents in total, and vice versa. No correlation was observed between the release rate of manganese and the alloy composition. Released main alloy constituents were neither proportional to the bulk alloy composition nor to the surface oxide composition.

  • 90.
    Herting, Gunilla
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Odnevall Wallinder, Inger
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Leygraf, Christofer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Factors that influence the release of metals from stainless steels exposed to physiological media2006Ingår i: Corrosion Science, ISSN 0010-938X, E-ISSN 1879-0496, Vol. 48, nr 8, s. 2120-2132Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Release rates of chromium, nickel and iron from grade 304 stainless steel with three different surface finishes, BA, 2B and 2D, have been determined after exposure to artificial lysosomal fluid. Metal release rates are discussed in relation to corrosion resistance, compositional changes of the outermost surface film of the stainless steel and to measurements of the effective surface area and roughness. The total metal release decreased in the following sequence: 2D > 2B approximate to BA, and was primarily related to the electrochemically active surface area. No direct correlation was observed between corrosion resistance and metal release rates.

  • 91.
    Herting, Gunilla
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Odnevall Wallinder, Inger
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Leygraf, Christofer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Metal release from various grades of stainless steel exposed to synthetic body fluids2007Ingår i: Corrosion Science, ISSN 0010-938X, E-ISSN 1879-0496, Vol. 49, nr 1, s. 103-111Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Release rates of individual alloy constituents have been determined from seven grades of stainless steels exposed to two synthetic body fluids, used as surrogates for different areas of potential exposure in the lung: "Gamble's solution", (pH 7.4) that represents the interstitial fluid of the deep lung, and artificial lysosomal fluid (ALF) that represents the more acidic (pH 4.5-5) milieu of particles following their phagocytosis by macrophages. Total metal release rates from all grades of stainless steel investigated were low (< 5 mu g cm(-2) week(-1)). The more acidic environment of ALF resulted in significantly higher total metal release rates (0.3-4.6 mu g cm(-2) week(-1)) compared to Gamble's solution (< 0.1 mu g cm(-2) week(-1)).

  • 92.
    Herting, Gunilla
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Odnevall Wallinder, Inger
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Leygraf, Christofer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Metal release rate from AISI 316L stainless steel and pure Fe, Cr and Ni into a synthetic biological medium: a comparison2008Ingår i: Journal of Environmental Monitoring, ISSN 1464-0325, E-ISSN 1464-0333, Vol. 10, nr 9, s. 1092-1098Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Metal release rates from stainless steel grade 316L were investigated in artificial lysosomal fluid (ALF), simulating a human inflammatory cell response. The main focus was placed on release rates of main alloying elements using graphite furnace atomic absorption spectroscopy, and changes in surface oxide composition by means of X-ray photoelectron spectroscopy. To emphasise that alloys and pure metals possess totally different intrinsic properties, comparative studies were performed on the pure alloying constituents: iron, nickel and chromium. Significant differences in release rates were observed due to the presence of a passive surface film on stainless steel. Iron and nickel were released at rates more than 300 times lower from the 316L alloy compared with the pure metals whereas the release rate of chromium was similar. Iron was preferentially released compared with nickel and chromium. Immersion in ALF resulted in the gradual enrichment of chromium in the surface film, a small increase of nickel, and the reduction of oxidized iron with decreasing release rates of alloy constituents as a result. As expected, released metals from stainless steel grade 316L were neither in proportion to the bulk alloy composition nor to the surface film composition.

  • 93.
    Herting, Gunilla
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Odnevall Wallinder, Inger
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Leygraf, Christofer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Release of Cr, Ni and Fe from stainless steel alloys and the pure metals2004Konferensbidrag (Refereegranskat)
    Abstract [en]

    The objective of this study is to demonstrate differences in release rates of chromium, nickel and iron from stainless steel alloys (grade 304 and 316) and pure metals exposed under identical conditions. The study was initiated to fill significant gaps of knowledge on metal release from stainless steels in external constructions [1-2] and to elucidate the difference between estimated release rates from nominal alloy compositions and measured rates.The results are based on laboratory investigations in a specially designed chamber which permits artificial rain to be introduced at a given rain composition and intensity. Metal release rates, and its kinetics as a function of rain duration and volume, were investigated during continuous eight-hour rain events of constant intensity (≈4 mmhr-1) and pH (4.3). In addition, changes in surface composition with time were monitored with XPS for the stainless steel alloys.Selected results from the investigation show the release rate of nickel and iron from stainless steel alloys to be significantly lower than rates from the pure metals. Similar release rates of chromium are seen from stainless steel alloys and the pure metal as a result of the presence of a chromium-rich passive film on both surfaces. The proportion of release rates between chromium and nickel (<1) differs significantly from the corresponding bulk ratio (>1.5).

  • 94. Hosseinpour, S.
    et al.
    Leygraf, Christopher
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Yt- och korrosionsvetenskap.
    Gretic, Z. H.
    Mioc, E. K.
    Curkovic, H. O.
    Bochmann, S.
    Bachmann, J.
    Waegner, V.
    Virtanen, S.
    Peukert, W.
    Self-assembled monolayers as corrosion inhibitors; indoor, marine and biologically relevant exposure2017Ingår i: EUROCORR 2017 - The Annual Congress of the European Federation of Corrosion, 20th International Corrosion Congress and Process Safety Congress 2017, Asociace koroznich inzenyru z.s.- AKI - Czech Association of Corrosion Engineers , 2017Konferensbidrag (Refereegranskat)
  • 95.
    Hosseinpour, Saman
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Forslund, Mattias
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Johnson, C. Magnus
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Pan, Jinshan
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Leygraf, Christofer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Atmospheric corrosion of Cu, Zn, and Cu-Zn alloys protected by self-assembled monolayers of alkanethiols2016Ingår i: Surface Science, ISSN 0039-6028, E-ISSN 1879-2758, Vol. 648, s. 170-176Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    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.

  • 96.
    Hosseinpour, Saman
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Götelid, Mats
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik, Materialfysik, MF.
    Leygraf, Christofer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Johnson, C. Magnus
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Self-Assembled Monolayers as Inhibitors for the Atmospheric Corrosion of Copper Induced by Formic Acid: A Comparison between Hexanethiol and Hexaneselenol2014Ingår i: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 161, nr 1, s. C50-C56Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The corrosion protection by self-assembled monolayers (SAMs) of hexanethiol and hexaneselenol has been explored on copper exposed to humid air containing formic acid, a corrosive environment relevant for indoor atmospheric corrosion. The kinetics of the formation of corrosion products on SAM covered copper was followed using in-situ infrared reflection/absorption spectroscopy (IRAS) and compared with that of bare copper. Both SAMs initially showed a corrosion protection ability. The prolonged exposure of hexanethiol copper resulted in a reduced formation rate of copper formate and copper hydroxide compared to bare copper, while on bare and hexaneselenol covered samples copper (I) oxide, copper formate, and copper hydroxide were observed. To assess the quality of the SAMs during the sample exposure, vibrational sum frequency spectroscopy (VSFS) was used. It was found that hexaneselenol molecules are locally removed from the surface during corrosion in contrast to their thiol counterparts. This created localized galvanic effects which resulted in an accelerated corrosion of selenol covered copper. X-ray photoelectron spectroscopy at elevated pressure demonstrated that the hexanethiol removed thin oxide layers upon adsorption. A contributing parameter to the enhanced corrosion inhibiting ability of hexanethiol could be its greater ability than hexaneselenol to bind to the copper surface during its deposition and sample exposure.

  • 97.
    Hosseinpour, Saman
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Hedberg, Jonas
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Leygraf, Christofer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Johnson, Magnus
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Baldelli, Steven
    Dpt of Chemistry, University of Houston, Texas, US.
    Initial Oxidation of Alkanethiol-Covered Copper Studied by Vibrational Sum Frequency Spectroscopy2011Ingår i: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 115, nr 48, s. 23871-23879Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The oxidation of octadecanethiol (ODT, CH3-(CH2)17SH)-covered copper in dry air has been studied by in situ vibrational sum frequency spectroscopy (VSFS), infrared reflection absorption spectroscopy (IRAS), and cathodic reduction (CR). During the first 10 h of exposure, the VSF spectral line shape in the CH stretching region changed

    significantly, with resonances observed as dips being transformed into peaks. This was attributed to a phase change in the nonresonant sum frequency signal due to the formation of a thin layer of copper(I) oxide beneath the ODT. Complementary cathodic reduction and infrared reflection/absorption spectroscopy studies yielded a thickness of the oxide layer of <2 nm after 19 h exposure. An orientation analysis on the adsorbed molecules by VSFS indicated a decreased tilt angle of the terminating methyl groups with respect to the surface normal during the formation of the oxide layer.

  • 98.
    Hosseinpour, Saman
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Johnson, C. Magnus
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Leygraf, Christofer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Alkanethiols as inhibitors for the atmospheric corrosion of copper induced by formic acid: Effect of chain length2013Ingår i: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 160, nr 6, s. C270-C276Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Self assembled monolayers (SAMs) of n-alkanethiols of different chain length (4, 6, 8, 12, and 18 carbons in the chain) have been explored as corrosion inhibitors for copper exposed to humidified air containing formic acid, an environment used to mimic accelerated indoor atmospheric corrosion. Near-surface sensitive in-situ infrared reflection/absorption spectroscopy combined with interface sensitive vibrational sum frequency spectroscopy revealed unique molecular information on the role of each SAM during ongoing corrosion. All SAMs protect copper against corrosion, and this ability increases continuously with chain length. Their structural order is high prior to exposure, but an increased disorder is observed as a result of the corrosion process. The protection ability of the SAMs is attributed to a selective hindrance of the corrosion stimulators water, oxygen gas, and formic acid to reach the copper-SAM interface through each SAM, which results in different corrosion mechanisms on SAM protected copper and unprotected copper. This significantly retards the formation of the corrosion products copper hydroxide and copper formate, and results in essentially no formation of cuprite.

  • 99.
    Hosseinpour, Saman
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Schwind, Markus
    Kasemo, Bengt
    Leygraf, Christofer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Johnson, C. Magnus
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Integration of Quartz Crystal Microbalance with Vibrational Sum Frequency Spectroscopy-Quantification of the Initial Oxidation of Alkanethiol-Covered Copper2012Ingår i: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 116, nr 46, s. 24549-24557Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We report the first integration of the interface sensitive technique vibrational sum frequency spectroscopy (VSFS) and the mass sensitive technique quartz crystal microbalance (QCM). VSFS-QCM has been applied in-situ to follow the formation of a thin Cu2O-like oxide on octadecanethiol-covered copper in dry air at ambient pressure conditions. We observed significant changes and an evolution of the VSF spectra caused by alterations in the electronic properties of the metal surface, and simultaneous shifts in the QCM resonance frequency due to a mass change during the formation of the oxide. QCM and VSFS exhibit a resolution corresponding to the formation of around 2% and 5% of an ideal monolayer of Cu2O, respectively. The successful integration of QCM increases the versatility of VSFS in numerous applications, where simultaneous in situ mass and spectroscopic information is desirable.

  • 100.
    Johnson, C. Magnus
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Hosseinpour, Saman
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Leygraf, Christofer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    In-situ studies of the reactivity of copper surfaces protected by self-assembled monolayers2014Ingår i: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 248Artikel i tidskrift (Övrigt vetenskapligt)
12345 51 - 100 av 220
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