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Publications (10 of 15) Show all publications
Li, H., Merkl, P., Sommertune, J., Thersleff, T. & Sotiriou, G. (2022). SERS Hotspot Engineering by Aerosol Self-Assembly of Plasmonic Ag Nanoaggregates with Tunable Interparticle Distance. Advanced Science, 9(22), Article ID 2201133.
Open this publication in new window or tab >>SERS Hotspot Engineering by Aerosol Self-Assembly of Plasmonic Ag Nanoaggregates with Tunable Interparticle Distance
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2022 (English)In: Advanced Science, E-ISSN 2198-3844, Vol. 9, no 22, article id 2201133Article in journal (Refereed) Published
Abstract [en]

Surface-enhanced Raman scattering (SERS) is a powerful sensing technique. However, the employment of SERS sensors in practical applications is hindered by high fabrication costs from processes with limited scalability, poor batch-to-batch reproducibility, substrate stability, and uniformity. Here, highly scalable and reproducible flame aerosol technology is employed to rapidly self-assemble uniform SERS sensing films. Plasmonic Ag nanoparticles are deposited on substrates as nanoaggregates with fine control of their interparticle distance. The interparticle distance is tuned by adding a dielectric spacer during nanoparticle synthesis that separates the individual Ag nanoparticles within each nanoaggregate. The dielectric spacer thickness dictates the plasmonic coupling extinction of the deposited nanoaggregates and finely tunes the Raman hotspots. By systematically studying the optical and morphological properties of the developed SERS surfaces, structure–performance relationships are established and the optimal hot-spots occur for interparticle distance of 1 to 1.5 nm among the individual Ag nanoparticles, as also validated by computational modeling, are identified for the highest signal enhancement of a molecular Raman reporter. Finally, the superior stability and batch-to-batch reproducibility of the developed SERS sensors are demonstrated and their potential with a proof-of-concept practical application in food-safety diagnostics for pesticide detection on fruit surfaces is explored. © 2022 The Authors.

Place, publisher, year, edition, pages
John Wiley and Sons Inc, 2022
Keywords
flame aerosol deposition, pesticide residue detection, plasmonic nanoparticles, SERS substrate fabrication, surface-enhanced Raman scattering (SERS), Aerosols, Metal nanoparticles, Pesticides, Plasmonics, Raman scattering, Self assembly, Silver nanoparticles, Substrates, Surface scattering, Synthesis (chemical), Enhanced Raman scattering, Flame aerosol depositions, Pesticides residue detection, Plasmonic nanoparticle, Raman scattering substrate, Surface enhanced Raman, Surface-enhanced raman scattering, Surface-enhanced raman scattering substrate fabrication, Fabrication
National Category
Other Physics Topics
Identifiers
urn:nbn:se:ri:diva-59337 (URN)10.1002/advs.202201133 (DOI)2-s2.0-85131310184 (Scopus ID)
Note

Funding details: European Research Council, ERC; Funding details: Stiftelsen för Strategisk Forskning, SSF, FFL18‐0043, RMX18‐0043; Funding details: Karolinska Institutet, KI; Funding details: Vetenskapsrådet, VR, 2016–05113, 2018‐05798, 2021‐02059, 2021–05494; Funding details: Horizon 2020, 758705; Funding text 1: This work received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (ERC Grant Agreement No. 758705). Funding from the Karolinska Institutet, the Swedish Foundation for Strategic Research (SSF) (FFL18‐0043, RMX18‐0043) and the Swedish Research Council (No. 2021–05494, 2021‐02059, 2018‐05798) is kindly acknowledged. The authors thank Birgitta Henriques‐Normark, Staffan Normark, and the BHN group (KI) for the insightful discussions. T.T. acknowledges funding from the Swedish Research Council (No. 2016–05113). The Karolinska Institutet 3D‐EM facility is kindly acknowledged for the acquisition of TEM images and use of their equipment.

Available from: 2022-06-20 Created: 2022-06-20 Last updated: 2023-01-03Bibliographically approved
Zhao, W., Sugunan, A., Gillgren, T., Larsson, J. A., Zhang, Z.-B., Zhang, S.-L., . . . Ahniyaz, A. (2022). Surfactant-free starch-graphene composite films as simultaneous oxygen and water vapour barriers. npj 2D Materials and Applications, 6(1), Article ID 20.
Open this publication in new window or tab >>Surfactant-free starch-graphene composite films as simultaneous oxygen and water vapour barriers
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2022 (English)In: npj 2D Materials and Applications, ISSN 2397-7132, Vol. 6, no 1, article id 20Article in journal (Refereed) Published
Abstract [en]

A single coating formulation for multifunctional composites, such as a gas barrier against both oxygen and water vapour, is the holy grail for the packaging industry. Since the last decade, graphene has been touted as the ideal barrier material in composites due to its morphology and impermeability to all gases. However, this prospect is limited by either poor dispersion of graphene or excess surfactants to aid the dispersion, both leading to shortcuts that allow gas permeation through the composite. Here, we demonstrate a combined gas barrier with starch-graphene composite films made from a single formulation of surfactant-free starch nanoparticle-stabilized graphene dispersion (2.97 mg mL−1). Hence, the incorporated graphene reduces the permeability of both the oxygen and the water vapour by over 70% under all the relative humidity conditions tested. Moreover, these films are foldable and electrically conductive (9.5 S m−1). Our surfactant-free approach of incorporating graphene into an industrially important biopolymer is highly relevant to the packaging industry, thus offering cost-effective and water-based solution depositions of multifunctional composite films for wide-ranging applications, such as gas barriers in food packaging. © 2022, The Author(s).

Place, publisher, year, edition, pages
Nature Research, 2022
Keywords
Biopolymers, Composite films, Conductive films, Cost effectiveness, Dispersions, Gas permeable membranes, Oxygen, Starch, Surface active agents, Water vapor, Barrier material, Coating formulations, Gas barrier, Graphene composites, Multifunctional composites, Oxygen vapors, Packaging industry, Surfactant-free, Water vapour, Water vapour barrier, Graphene
National Category
Polymer Technologies
Identifiers
urn:nbn:se:ri:diva-59006 (URN)10.1038/s41699-022-00292-x (DOI)2-s2.0-85126771096 (Scopus ID)
Note

Funding details: Stiftelsen för Strategisk Forskning, SSF, FID-15-0105; Funding text 1: This work was financially supported by the Swedish Foundation for Strategic Research (SSF, grant no. FID-15-0105) and BillerudKorsnäs AB. The authors thank Karin Hallstensson for support with the SEM imaging, Mikael Sundin for performing the XPS analysis and Marie Ernstsson for interpreting the data, Andreas Fall and Niklas Nordgren for insightful discussions and review of the manuscript.; Funding text 2: This work was financially supported by the Swedish Foundation for Strategic Research (SSF, grant no. FID-15-0105) and BillerudKorsna?s AB. The authors thank Karin Hallstensson for support with the SEM imaging, Mikael Sundin for performing the XPS analysis and Marie Ernstsson for interpreting the data, Andreas Fall and Niklas Nordgren for insightful discussions and review of the manuscript.

Available from: 2022-04-21 Created: 2022-04-21 Last updated: 2023-05-09Bibliographically approved
Janhäll, S., Petersson, M., Davidsson, K., Öman, T., Sommertune, J., Kåredal, M., . . . Rissler, J. (2021). Release of carbon nanotubes during combustion of polymer nanocomposites in a pilot-scale facility for waste incineration. NanoImpact, 24, Article ID 100357.
Open this publication in new window or tab >>Release of carbon nanotubes during combustion of polymer nanocomposites in a pilot-scale facility for waste incineration
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2021 (English)In: NanoImpact, ISSN 2452-0748, Vol. 24, article id 100357Article in journal (Refereed) Published
Abstract [en]

Nanocomposites, formed by incorporating nanoparticles into a matrix of standard materials, are increasing on the market. Little focus has been directed towards safe disposal and recycling of these new materials even though the disposal has been identified as a phase of the products' life cycle with a high risk of uncontrolled emissions of nanomaterials. In this study, we investigate if the carbon nanotubes (CNTs), when used as a filler in two types of polymers, are fully destructed in a pilot-scale combustion unit designed to mimic the combustion under waste incineration. The two polymer nanocomposites studied, polycarbonate (PC) with CNT and high-density polyethylene (HDPE) with CNT, were incinerated at two temperatures where the lower temperature just about fulfilled the European waste incineration directive while the upper was chosen to be on the safe side of fulfilling the directive. Particles in the flue gas were sampled and analysed with online and offline instrumentation along with samples of the bottom ash. CNTs could be identified in the flue gas in all experiments, although present to a greater extent when the CNTs were introduced in PC as compared to in HDPE. In the case of using PC as polymer matrix, CNTs were identified in 3–10% of the analysed SEM images while for HDPE in only ~0.5% of the images. In the case of PC, the presence of CNTs decreased with increasing bed temperature (from 10% to 3% of the images). The CNTs identified were always in bundles, often coated with remnants of the polymer, forming particles of ~1–4 μm in diameter. No CNTs were identified in the bottom ash, likely explained by the difference in time when the bottom ash and fly ash are exposed to high temperatures (~hours compared to seconds) in the pilot facility. The results suggest that the residence time of the fly ash in the combustion zone is not long enough to allow full oxidation of the CNTs. Thus, the current regulation on waste incineration (requiring a residence time of the flue gas >850 °C during at least 2 s) may not be enough to obtain complete destruction of CNTs in polymer composites. Since several types of CNTs are known to be toxic, we stress the need for further investigation of the fate and toxicity of CNTs in waste treatment processes.

Keywords
Waste incineration, Polymer, CNT, Particle, Fly ash, Nanocomposites
National Category
Energy Engineering
Identifiers
urn:nbn:se:ri:diva-58176 (URN)10.1016/j.impact.2021.100357 (DOI)
Available from: 2022-01-14 Created: 2022-01-14 Last updated: 2023-06-07Bibliographically approved
Zhao, W., Sugunan, A., Gillgren, T., Larsson, J., Zhang, Z.-B., Zhang, S.-L., . . . Ahniyaz, A. (2021). Surfactant-Free Stabilization of Aqueous Graphene Dispersions Using Starch as a Dispersing Agent. ACS Omega, 6(18), 12050-12062
Open this publication in new window or tab >>Surfactant-Free Stabilization of Aqueous Graphene Dispersions Using Starch as a Dispersing Agent
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2021 (English)In: ACS Omega, E-ISSN 2470-1343, Vol. 6, no 18, p. 12050-12062Article in journal (Refereed) Published
Abstract [en]

Attention to graphene dispersions in water with the aid of natural polymers is increasing with improved awareness of sustainability. However, the function of biopolymers that can act as dispersing agents in graphene dispersions is not well understood. In particular, the use of starch to disperse pristine graphene materials deserves further investigation. Here, we report the processing conditions of aqueous graphene dispersions using unmodified starch. We have found that the graphene content of the starch-graphene dispersion is dependent on the starch fraction. The starch-graphene sheets are few-layer graphene with a lateral size of 3.2 μm. Furthermore, topographical images of these starch-graphene sheets confirm the adsorption of starch nanoparticles with a height around 5 nm on the graphene surface. The adsorbed starch nanoparticles are ascribed to extend the storage time of the starch-graphene dispersion up to 1 month compared to spontaneous aggregation in a nonstabilized graphene dispersion without starch. Moreover, the ability to retain water by starch is reduced in the presence of graphene, likely due to environmental changes in the hydroxyl groups responsible for starch-water interactions. These findings demonstrate that starch can disperse graphene with a low oxygen content in water. The aqueous starch-graphene dispersion provides tremendous opportunities for environmental-friendly packaging applications. © 2021 American Chemical Society.

Place, publisher, year, edition, pages
American Chemical Society, 2021
National Category
Physical Chemistry
Identifiers
urn:nbn:se:ri:diva-53478 (URN)10.1021/acsomega.1c00699 (DOI)2-s2.0-85106450176 (Scopus ID)
Note

Funding details: Stiftelsen för Strategisk Forskning, SSF, FID-15-0105; Funding text 1: This work was financially supported by the Swedish Foundation for Strategic Research (SSF, grant no. FID-15-0105) and BillerudKorsnäs AB. The authors thank Karin Hallstensson for support with the SEM/STEM imaging.

Available from: 2021-06-17 Created: 2021-06-17 Last updated: 2023-05-26Bibliographically approved
Phan-Xuan, T., Bogdanova, E., Sommertune, J., Millqvist-Fureby, A., Fransson, J., Terry, A. & Kocherbitov, V. (2021). The role of water in the reversibility of thermal denaturation of lysozyme in solid and liquid states. Biochemistry and Biophysics Reports, 28, Article ID 101184.
Open this publication in new window or tab >>The role of water in the reversibility of thermal denaturation of lysozyme in solid and liquid states
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2021 (English)In: Biochemistry and Biophysics Reports, ISSN 2405-5808, Vol. 28, article id 101184Article in journal (Refereed) Published
Abstract [en]

Although unfolding of protein in the liquid state is relatively well studied, its mechanisms in the solid state, are much less understood. We evaluated the reversibility of thermal unfolding of lysozyme with respect to the water content using a combination of thermodynamic and structural techniques such as differential scanning calorimetry, synchrotron small and wide-angle X-ray scattering (SWAXS) and Raman spectroscopy. Analysis of the endothermic thermal transition obtained by DSC scans showed three distinct unfolding behaviors at different water contents. Using SWAXS and Raman spectroscopy, we investigated reversibility of the unfolding for each hydration regime for various structural levels including overall molecular shape, secondary structure, hydrophobic and hydrogen bonding interactions. In the substantially dehydrated state below 37 wt% of water the unfolding is an irreversible process and can be described by a kinetic approach; above 60 wt% the process is reversible, and the thermodynamic equilibrium approach is applied. In the intermediate range of water contents between 37 wt% and 60 wt%, the system is phase separated and the thermal denaturation involves two processes: melting of protein crystals and unfolding of protein molecules. A phase diagram of thermal unfolding/denaturation in lysozyme - water system was constructed based on the experimental data. © 2021 The Authors

Place, publisher, year, edition, pages
Elsevier B.V., 2021
Keywords
Differential scanning calorimetry (DSC), Hydration, Raman, Small and wide-angle X-ray scattering (SAXS/WAXS), Solid state protein, Thermal denaturation/unfolding
National Category
Physical Chemistry
Identifiers
urn:nbn:se:ri:diva-57335 (URN)10.1016/j.bbrep.2021.101184 (DOI)2-s2.0-85120645297 (Scopus ID)
Note

Funding details: VINNOVA, 2018092983, 201902356; Funding text 1: This research was funded by the Swedish Governmental Agency for Innovation Systems (VINNOVA) and was carried out within the competence centre NextBioForm. ALBA synchrotron (beamline NCD-SWEET) is thanked for allocation of the SAXS/WAXS beamtimes (proposal numbers 2018092983 and 201902356). Last, we would like to express our gratitude and respect to our co-author and Chairman of NextBioForm Jonas Fransson who passed away in August 2021.

Available from: 2021-12-23 Created: 2021-12-23 Last updated: 2023-05-09Bibliographically approved
Bengtsson, A., Hecht, P., Sommertune, J., Ek, M., Sedin, M. & Sjöholm, E. (2020). Carbon Fibers from Lignin-Cellulose Precursors: Effect of Carbonization Conditions. ACS Sustainable Chemistry and Engineering, 8(17), 6826-6833
Open this publication in new window or tab >>Carbon Fibers from Lignin-Cellulose Precursors: Effect of Carbonization Conditions
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2020 (English)In: ACS Sustainable Chemistry and Engineering, E-ISSN 2168-0485, Vol. 8, no 17, p. 6826-6833Article in journal (Refereed) Published
Abstract [en]

Carbon fibers (CFs) are gaining increasing importance in lightweight composites, but their high price and reliance on fossil-based raw materials stress the need for renewable and cost-efficient alternatives. Kraft lignin and cellulose are renewable macromolecules available in high quantities, making them interesting candidates for CF production. Dry-jet wet spun precursor fibers (PFs) from a 70/30 w/w blend of softwood kraft lignin (SKL) and fully bleached softwood kraft pulp (KP) were converted into CFs under fixation. The focus was to investigate the effect of carbonization temperature and time on the CF structure and properties. Reducing the carbonization time from 708 to 24 min had no significant impact on the tensile properties. Increasing the carbonization temperature from 600 to 800 °C resulted in a large increase in the carbon content and tensile properties, suggesting that this is a critical region during carbonization of SKL:KP PFs. The highest Young's modulus (77 GPa) was obtained after carbonization at 1600 °C, explained by the gradual transition from amorphous to nanocrystalline graphite observed by Raman spectroscopy. On the other hand, the highest tensile strength (1050 MPa) was achieved at 1000 °C, a decrease being observed thereafter, which may be explained by an increase in radial heterogeneity.

Place, publisher, year, edition, pages
American Chemical Society, 2020
Keywords
carbon fiber, carbonization, cellulose, dry-jet wet spinning, fully bleached softwood kraft pulp, softwood kraft lignin
National Category
Engineering and Technology
Identifiers
urn:nbn:se:ri:diva-44995 (URN)10.1021/acssuschemeng.0c01734 (DOI)2-s2.0-85084748026 (Scopus ID)
Available from: 2020-06-01 Created: 2020-06-01 Last updated: 2023-05-09Bibliographically approved
Kharitonov, D., Sommertune, J., Örnek, C., Ryl, J., Kurilo, I., Claesson, P. M. & Pan, J. (2019). Corrosion inhibition of aluminium alloy AA6063-T5 by vanadates: Local surface chemical events elucidated by confocal Raman micro-spectroscopy. Corrosion Science, 148, 237-250
Open this publication in new window or tab >>Corrosion inhibition of aluminium alloy AA6063-T5 by vanadates: Local surface chemical events elucidated by confocal Raman micro-spectroscopy
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2019 (English)In: Corrosion Science, ISSN 0010-938X, E-ISSN 1879-0496, Vol. 148, p. 237-250Article in journal (Refereed) Published
Abstract [en]

Chemical interactions between aqueous vanadium species and aluminium alloy AA6063-T5 were investigated in vanadate-containing NaCl solutions. Confocal Raman and X-ray photoelectron spectroscopy experiments were utilised to gain insight into the mechanism of corrosion inhibition by vanadates. A greenish-grey coloured surface layer, consisting of V+4 and V+5 polymerized species, was seen to form on the alloy surface, especially on top of cathodic micrometre-sized IMPs, whereby suppressing oxygen reduction kinetics. The results suggest a two-step mechanism of corrosion inhibition in which V+5 species are first reduced to V+4 or V+3 species above cathodic IMPs, and then oxidized to mixed-valence V+5/V+4 polymerized compounds. 

Keywords
A. Alloy, A. Aluminium, B. Raman spectroscopy, B. SEM, B. XPS, C. Vanadate inhibitor, Corrosion inhibitors, Electrolytic reduction, Sodium alloys, Sodium chloride, Transition metal compounds, Vanadium alloys, X ray photoelectron spectroscopy, Chemical interactions, Corrosion inhibition, Local surfaces, Mechanism of corrosion, Oxygen reduction kinetics, Two-step mechanisms, Vanadium species, Aluminum corrosion
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-37038 (URN)10.1016/j.corsci.2018.12.011 (DOI)2-s2.0-85059158841 (Scopus ID)
Note

 Funding details: Belarusian State University, BSU; Funding details: IP2015067574; Funding details: Ministry of Education of the Republic of Belarus, 20161135; Funding details: Stiftelsen för Strategisk Forskning; Funding details: Kungliga Tekniska Högskolan, KTH; Funding details: Sjögren’s Syndrome Foundation, RMA11-0090; Funding details: Knut och Alice Wallenbergs Stiftelse;

Available from: 2019-01-17 Created: 2019-01-17 Last updated: 2020-06-29Bibliographically approved
Baresel, C., Schaller, V., Jonasson, C., Johansson, C., Bordes, R., Chauhan, V., . . . Welling, S. (2019). Functionalized magnetic particles for water treatment. Heliyon, 5(8), Article ID e02325.
Open this publication in new window or tab >>Functionalized magnetic particles for water treatment
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2019 (English)In: Heliyon, E-ISSN 2405-8440, Vol. 5, no 8, article id e02325Article in journal (Refereed) Published
Abstract [en]

In this study, we have taken the concept of water treatment by functionalized magnetic particles one step forward by integrating the technology into a complete proof of concept, which included the preparation of surface modified beads, their use as highly selective absorbents for heavy metals ions (Zinc, Nickel), and their performance in terms of magnetic separation. The separation characteristics were studied both through experiments and by simulations. The data gathered from these experimental works enabled the elaboration of various scenarios for Life Cycle Analysis (LCA). The LCA showed that the environmental impact of the system is highly dependent on the recovery rate of the magnetic particles. The absolute impact on climate change varied significantly among the scenarios studied and the recovery rates. The results support the hypothesis that chelation specificity, magnetic separation and bead recovery should be optimized to specific targets and applications. 

Place, publisher, year, edition, pages
Elsevier Ltd, 2019
Keywords
Chemical engineering, Environmental science, Life cycle assessment, Magnetic particle, Materials chemistry, Nanotechnology, Pollutant, Water treatment
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-39844 (URN)10.1016/j.heliyon.2019.e02325 (DOI)2-s2.0-85070906522 (Scopus ID)
Note

This work was supported by VINNOVA , the Swedish Governmental Agency for Innovation, within the call Innovationer för ett hållbart samhälle: miljö och transport.

Available from: 2019-10-01 Created: 2019-10-01 Last updated: 2024-03-04Bibliographically approved
Andersson, I. M., Millqvist-Fureby, A., Sommertune, J., Alexander, M., Hellström, N., Glantz, M., . . . Bergenståhl, B. (2019). Impact of protein surface coverage and layer thickness on rehydration characteristics of milk serum protein/lactose powder particles. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 561, 395-404
Open this publication in new window or tab >>Impact of protein surface coverage and layer thickness on rehydration characteristics of milk serum protein/lactose powder particles
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2019 (English)In: Colloids and Surfaces A: Physicochemical and Engineering Aspects, ISSN 0927-7757, E-ISSN 1873-4359, Vol. 561, p. 395-404Article in journal (Refereed) Published
Abstract [en]

Spray-dried powders were produced from milk serum protein concentrate and lactose in varying ratios, and the rehydration characteristics of the powders were evaluated. The dissolution rate was estimated with a flow-cell based technique, and the external and internal distribution of the powder components were evaluated with X-ray photoelectron spectroscopy and confocal Raman microscopy, respectively. The surface of the powder particles is more or less covered by a thin protein layer. A phase segregation between protein and lactose is observed in the interior of the particle resulting in a protein rich layer in the vicinity of the surface. However, the protein layer in the vicinity of the particle surface tends to become thinner as the bulk protein concentration increases in the powders (from 10 to 60% w/w). The time for the spontaneous imbibition to occur show a linear correlation with the protein surface coverage. The dissolution rate of powders containing 0.1% w/w protein is around 60 times faster than for a powder containing 1% w/w protein but the dissolution rate of powders containing 1% and 100% w/w differ only by a factor of 2. Thus, it is suggested that the outer protein layer becomes denser at the interface as the protein content increases in the powders, thereby causing poorer rehydration characteristics of the powders (especially for low protein concentrations 0.1–1% w/w). This insight has relevance for the formulation of whey protein powders with improved rehydration characteristics. © 2018 Elsevier B.V.

Keywords
Confocal raman microscopy, Lactose, Milk serum protein, Phase segregation, Rehydration, Spray drying, Body fluids, Dissolution, Phase separation, Powders, Segregation (metallography), Sugars, Surface segregation, X ray photoelectron spectroscopy, Milk serum proteins, Phase segregations, Proteins
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-36591 (URN)10.1016/j.colsurfa.2018.10.073 (DOI)2-s2.0-85056673089 (Scopus ID)
Note

Funding details: Lunds Universitet

Available from: 2018-12-17 Created: 2018-12-17 Last updated: 2023-05-09Bibliographically approved
Kharitonov, D. S., Örnek, C., Claesson, P. M., Sommertune, J., Zharskii, I. M., Kurilo, I. I. & Pan, J. (2018). Corrosion Inhibition of Aluminum Alloy AA6063-T5 by Vanadates: Microstructure Characterization and Corrosion Analysis. Journal of the Electrochemical Society, 5(3), C116-C126
Open this publication in new window or tab >>Corrosion Inhibition of Aluminum Alloy AA6063-T5 by Vanadates: Microstructure Characterization and Corrosion Analysis
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2018 (English)In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 5, no 3, p. C116-C126Article in journal (Refereed) Published
Abstract [en]

Corrosion inhibition of aluminum alloy AA6063-T5 by vanadates (NaVO3) in 0.05 M NaCl solution has been investigated by electrochemical and weight loss measurements, and associated with microstructure and Volta potential data. X-ray diffraction, scanning electron microscopy, and energy dispersive spectroscopy analyses confirmed the presence of micrometer-sized Fe-rich Al4.01MnSi0.74, Al1.69Mg4Zn2.31, and FeAl3intermetallic phases (IMPs) and nanometer-sized CuAl2, ZnAl2, and Mg2Si precipitates in the microstructure. Scanning Kelvin probe force microscopy measurements showed Volta potential differences of up to 600 mV between the microstructure constituents indicating a high susceptibility to micro-galvanic corrosion, with interphase boundary regions exhibiting the highest propensity to corrosion. Most IMPs had cathodic character whereas some nanometer-sized Mg-rich particles exhibited anodic nature, with large Volta potential gradients within interphase regions of large cathodic particles. Electrochemical potentiodynamic polarization measurements indicated that the vanadates provided mixed corrosion inhibition effects, mitigating both oxygen reduction, occurring on cathodic IMPs, and anodic metal dissolution reaction, occurring on anodic sites, such as Mg2Si and interphase boundary regions. Electrochemical measurements indicated that the sodium metavanadate inhibitor blocks active metal dissolution, giving high inhibition efficiency (>95%) during the initial exposure, whereas long-term weight loss measurements showed that the efficacy decreases after prolonged exposure.

Keywords
Aluminum Alloy AA6063-T5 Sodium Metavanadate (NaVO3) Corrosion Inhibition Microstructure Characterization Scanning Kelvin Probe Force Microscopy (SKPFM) Electrochemical Impedance Spectroscopy (EIS)
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-34071 (URN)10.1149/2.0341803jes (DOI)2-s2.0-85044021625 (Scopus ID)
Available from: 2018-07-06 Created: 2018-07-06 Last updated: 2020-07-23Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-4697-9192

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