Change search
Refine search result
1234 1 - 50 of 180
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1. A. Hosseini, V.
    et al.
    Karlsson, L.
    Örnek, Cem
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science. Swerea KIMAB AB.
    Reccagni, P.
    Wessman, S.
    Engelberg, D.
    Microstructure and functionality of a uniquely graded super duplex stainless steel designed by a novel arc heat treatment method2018In: Materials Characterization, ISSN 1044-5803, E-ISSN 1873-4189, Vol. 139, p. 390-400Article in journal (Refereed)
    Abstract [en]

    A novel arc heat treatment technique was applied to design a uniquely graded super duplex stainless steel (SDSS), by subjecting a single sample to a steady state temperature gradient for 10 h. A new experimental approach was used to map precipitation in microstructure, covering aging temperatures of up to 1430 °C. The microstructure was characterized and functionality was evaluated via hardness mapping. Nitrogen depletion adjacent to the fusion boundary depressed the upper temperature limit for austenite formation and influenced the phase balance above 980 °C. Austenite/ferrite boundaries deviating from Kurdjumov–Sachs orientation relationship (OR) were preferred locations for precipitation of σ at 630–1000 °C, χ at 560–1000 °C, Cr2N at 600–900 °C and R between 550 °C and 700 °C. Precipitate morphology changed with decreasing temperature; from blocky to coral-shaped for σ, from discrete blocky to elongated particles for χ, and from polygonal to disc-shaped for R. Thermodynamic calculations of phase equilibria largely agreed with observations above 750 °C when considering nitrogen loss. Formation of intermetallic phases and 475 °C-embrittlement resulted in increased hardness. A schematic diagram, correlating information about phase contents, morphologies and hardness, as a function of exposure temperature, is introduced for evaluation of functionality of microstructures.

  • 2.
    Ahmad, Shargeel
    et al.
    Dalian Univ Technol, Inst Artificial Photosynthesis, State Key Lab Fine Chem, Dalian 116024, Peoples R China..
    Liu, Jinxuan
    Dalian Univ Technol, Inst Artificial Photosynthesis, State Key Lab Fine Chem, Dalian 116024, Peoples R China..
    Ji, Wei
    Dalian Univ Technol, Inst Artificial Photosynthesis, State Key Lab Fine Chem, Dalian 116024, Peoples R China..
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry. Dalian Univ Technol, Inst Artificial Photosynthesis, State Key Lab Fine Chem, Dalian 116024, Peoples R China.;KTH Royal Inst Technol, Sch Chem Sci & Engn, Dept Chem, S-10044 Stockholm, Sweden..
    Metal-Organic Framework Thin Film-Based Dye Sensitized Solar Cells with Enhanced Photocurrent2018In: Materials, ISSN 1996-1944, E-ISSN 1996-1944, Vol. 11, no 10, article id 1868Article in journal (Refereed)
    Abstract [en]

    Metal-organic framework thin film-based dye sensitized solar cell is fabricated with highly oriented, crystalline, and porous Zn-perylene metal-organic framework (MOF) thin film (SURMOF) which is integrated with Bodipy embedded in poly(methyl methacrylate). It has been demonstrated that the photocurrent can be enhanced by a factor of 5 relative to Zn-perylene MOF thin film due to triplet-triplet annihilation up-conversion between the Bodipy/PMMA sensitizer and the Zn-perylene MOF thin film acceptor using Co(bpy)(3)(2+/3+) as redox mediator.

  • 3.
    Alekseeva, L. A.
    et al.
    Natl Acad Sci Ukraine, B Verkin Inst Low Temp Phys & Engn, 47 Nauky Ave, UA-61103 Kharkov, Ukraine..
    Dobryden, Illia
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Determination of the low-temperature self-diffusion coefficient in solid p-H-2 from creep experiments2018In: Low temperature physics (Woodbury, N.Y., Print), ISSN 1063-777X, E-ISSN 1090-6517, Vol. 44, no 9, p. 946-951Article in journal (Refereed)
    Abstract [en]

    Dependencies of the relative elongation epsilon under the constantly applied stress at T = 1.8 K on the endurance time t of polycrystalline parahydrogen (p-H-2, similar to 0.2% of o-H-2) of high purity (99.9999 mol.%), with varying deuterium content, were measured. The region of linear dependence between the measured creep rates (epsilon) over dot of samples and the applied stress s was revealed. The conclusion that the low-temperature creep of the studied p-H-2 possesses a vacancy-type diffusion character was made on the basis of linear dependence (epsilon) over dot similar to s. Determination of the low-temperature self-diffusion coefficient of vacancies D in solid p-H-2, which characterizes the rate of low-temperature mass transfer, was performed. The cases of migration of vacancies in the crystal bulk, along boundaries separating individual crystallites, as well as between dislocations existing in crystals, are considered. A significant decrease in the (epsilon) over dot and D values with an increase in the isotope concentration in the samples was observed, while maintaining the linear relationship between (epsilon) over dot and s for the studied p-H-2. Published by AIP Publishing.

  • 4.
    Almandoz-Gil, Leire
    et al.
    Uppsala Univ, Dept Publ Hlth & Caring Sci, Mol Geriatr, SE-75185 Uppsala, Sweden..
    Welander, Hedvig
    Uppsala Univ, Dept Publ Hlth & Caring Sci, Mol Geriatr, SE-75185 Uppsala, Sweden..
    Ihse, Elisabeth
    Uppsala Univ, Dept Publ Hlth & Caring Sci, Mol Geriatr, SE-75185 Uppsala, Sweden..
    Khoonsari, Payam Emami
    Uppsala Univ, Dept Med Sci, SE-75185 Uppsala, Sweden..
    Musunuri, Sravani
    Uppsala Univ, Dept Med Sci, SE-75185 Uppsala, Sweden..
    Lendel, Christofer
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry.
    Sigvardson, Jessica
    BioArctic AB, Warfvinges Vag 35, SE-11251 Stockholm, Sweden..
    Karlsson, Mikael
    Uppsala Univ, Dept Engn Sci, SE-75121 Uppsala, Sweden..
    Ingelsson, Martin
    Uppsala Univ, Dept Publ Hlth & Caring Sci, Mol Geriatr, SE-75185 Uppsala, Sweden..
    Kultima, Kim
    Uppsala Univ, Dept Med Sci, SE-75185 Uppsala, Sweden..
    Bergstrom, Joakim
    Uppsala Univ, Dept Publ Hlth & Caring Sci, Mol Geriatr, SE-75185 Uppsala, Sweden..
    Low molar excess of 4-oxo-2-nonenal and 4-hydroxy-2-nonenal promote oligomerization of alpha-synuclein through different pathways (vol 110, pg 421, 2017)2018In: Free Radical Biology & Medicine, ISSN 0891-5849, E-ISSN 1873-4596, Vol. 117, p. 258-258Article in journal (Refereed)
  • 5. Angiolini, L.
    et al.
    Valetti, S.
    Cohen, B.
    Feiler, Adam
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science. Nanologica AB, Södertälje, Sweden.
    Douhal, A.
    Fluorescence imaging of antibiotic clofazimine encapsulated within mesoporous silica particle carriers: Relevance to drug delivery and the effect on its release kinetics2018In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 20, no 17, p. 11899-11911Article in journal (Refereed)
    Abstract [en]

    We report on the encapsulation of the antibiotic clofazimine (CLZ) within the pores of mesoporous silica particles having hydrophilic (CBET value of 137) and more hydrophobic (CBET value of 94 after calcination at 600 °C) surfaces. We studied the effect of pH on the released amount of CLZ in aqueous solutions and observed a maximum at pH 4.1 in correlation with the solubility of the drug. Less release of the drug was observed from the more hydrophobic particles which was attributed to a difference in the affinity of the drug to the carrier particles. Fluorescence lifetime imaging microscopy, emission spectra, and fluorescence lifetimes of single drug loaded particles provided detailed understanding and new knowledge of the physical form of the encapsulated drug and the distribution within the particles. The distribution of CLZ within the particles was independent of the surface chemistry of the particles. The confirmation of CLZ molecules as monomers or aggregates was revealed by controlled removal of the drug with solvent. Additionally, the observed optical "halo effect" in the fluorescent images was interpreted in terms of specific quenching of high concentration of molecules. The emission lifetime experiments suggest stronger interaction of CLZ with the more hydrophobic particles, which is relevant to its release. The results reported in this work demonstrate that tuning the hydrophilicity/hydrophobicity of mesoporous silica particles can be used as a tool to control the release without impacting their loading ability.

  • 6.
    Arafa, Wael Abdelgayed Ahmed
    et al.
    Jouf Univ, Coll Sci, Chem Dept, POB 72341, Sakaka, Aljouf, Saudi Arabia.;Fayoum Univ, Fac Sci, Chem Dept, POB 63514, Fayoum City, Egypt..
    Abdel-Magied, Ahmed Fawzy
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry. Nucl Mat Author, POB 530, Cairo, Egypt..
    An eco-compatible access to diversified bisoxazolone and bisimidazole derivatives2018In: ARKIVOC, ISSN 1551-7004, E-ISSN 1551-7012, p. 338-353Article in journal (Refereed)
    Abstract [en]

    An efficient, straight-forward and eco-friendly synthetic strategy for the assembly of novel bisoxazolones via a four-component, sequential reaction of dialdehydes, glycine, benzoyl chloride and acetic anhydride, using ultrasound radiation, is described. Additionally, a diverse group of new bisimidazoles has been synthesized in good yields by the sonication of diamines and (Z)-4-arylidene-2-phenyloxazol-5(4H)-ones. These approaches have resulted in a number of successful routes for the facile synthesis of bis-oxazolone and bis-imidazole frameworks within minutes of irradiation. Excellent outcomes using these environmentally-friendly parameters make these synthetic schemes ideal, sustainable, green-chemistry procedures and provide simple access towards the preparation of bisheterocycles. [GRAPHICS] .

  • 7. Armstronga, D. A.
    et al.
    Huie, R. E.
    Lymar, S.
    Koppenol, W. H.
    Merényi, Gabor
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry.
    Neta, P.
    Stanbury, D. M.
    Steenken, S.
    Wardman, P.
    Standard electrode potentials involving radicals in aqueous solution: Inorganic radicals2013In: BioInorganic Reaction Mechanisms, ISSN 2191-2491, Vol. 9, no 1-4, p. 59-61Article in journal (Refereed)
    Abstract [en]

    Inorganic radicals, such as superoxide and hydroxyl, play an important role in biology. Their tendency to oxidize or to reduce other compounds has been studied by pulse radiolysis; electrode potentials can be derived when equilibrium is established with a well-known reference compound. An IUPAC Task Group has evaluated the literature and produced the recommended standard electrode potentials for such couples as (O2/O2 ·-), (HO·, H+/H2O), (O3/O3 ·-), (Cl2/Cl2 ·-), (Br2 ·-/2Br-), (NO2 ·/NO2 -), and (CO3 ·-/CO3 2-). 

  • 8.
    Baath, Jenny Arnling
    et al.
    Chalmers Univ Technol, Div Ind Biotechnol, Dept Biol & Biol Engn, S-41296 Gothenburg, Sweden.;Chalmers Univ Technol, Wallenberg Wood Sci Ctr, S-41296 Gothenburg, Sweden..
    Martinez-Abad, Antonio
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience.
    Berglund, Jennie
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Larsbrink, Johan
    Chalmers Univ Technol, Div Ind Biotechnol, Dept Biol & Biol Engn, S-41296 Gothenburg, Sweden.;Chalmers Univ Technol, Wallenberg Wood Sci Ctr, S-41296 Gothenburg, Sweden..
    Vilaplana, Francisco
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Olsson, Lisbeth
    Chalmers Univ Technol, Div Ind Biotechnol, Dept Biol & Biol Engn, S-41296 Gothenburg, Sweden.;Chalmers Univ Technol, Wallenberg Wood Sci Ctr, S-41296 Gothenburg, Sweden..
    Mannanase hydrolysis of spruce galactoglucomannan focusing on the influence of acetylation on enzymatic mannan degradation2018In: Biotechnology for Biofuels, ISSN 1754-6834, E-ISSN 1754-6834, Vol. 11, article id 114Article in journal (Refereed)
    Abstract [en]

    Background: Galactoglucomannan (GGM) is the most abundant hemicellulose in softwood, and consists of a backbone of mannose and glucose units, decorated with galactose and acetyl moieties. GGM can be hydrolyzed into fermentable sugars, or used as a polymer in films, gels, and food additives. Endo-beta-mannanases, which can be found in the glycoside hydrolase families 5 and 26, specifically cleave the mannan backbone of GGM into shorter oligosaccharides. Information on the activity and specificity of different mannanases on complex and acetylated substrates is still lacking. The aim of this work was to evaluate and compare the modes of action of two mannanases from Cellvibrio japonicus (CjMan5A and CjMan26A) on a variety of mannan substrates, naturally and chemically acetylated to varying degrees, including naturally acetylated spruce GGM. Both enzymes were evaluated in terms of cleavage patterns and their ability to accommodate acetyl substitutions. Results: CjMan5A and CjMan26A demonstrated different substrate preferences on mannan substrates with distinct backbone and decoration structures. CjMan5A action resulted in higher amounts of mannotriose and mannotetraose than that of CjMan26A, which mainly generated mannose and mannobiose as end products. Mass spectrometric analysis of products from the enzymatic hydrolysis of spruce GGM revealed that an acetylated hexotriose was the shortest acetylated oligosaccharide produced by CjMan5A, whereas CjMan26A generated acetylated hexobiose as well as diacetylated oligosaccharides. A low degree of native acetylation did not significantly inhibit the enzymatic action. However, a high degree of chemical acetylation resulted in decreased hydrolyzability of mannan substrates, where reduced substrate solubility seemed to reduce enzyme activity. Conclusions: Our findings demonstrate that the two mannanases from C. japonicus have different cleavage patterns on linear and decorated mannan polysaccharides, including the abundant and industrially important resource spruce GGM. CjMan26A released higher amounts of fermentable sugars suitable for biofuel production, while CjMan5A, producing higher amounts of oligosaccharides, could be a good candidate for the production of oligomeric platform chemicals and food additives. Furthermore, chemical acetylation of mannan polymers was found to be a potential strategy for limiting the biodegradation of mannan-containing materials.

  • 9.
    Badal Tejedor, Maria
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science. RISE Research Intitutes of Sweden.
    Pazesh, Samaneh
    Nordgren, Niklas
    Schuleit, Michael
    Rutland, Mark W.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science. RISE Research Intitutes of Sweden.
    Alderborn, Göran
    Millqvist-Fureby, Anna
    Milling induced amorphisation andrecrystallization of α-lactose monohydrate2018In: International Journal of Pharmaceutics, ISSN 0378-5173, E-ISSN 1873-3476, Vol. 537, no 1-2, p. 140-147Article in journal (Refereed)
    Abstract [en]

    Preprocessing of pharmaceutical powders is a common procedure to condition the materials for a better manufacturing performance. However, such operations may induce undesired material properties modifications when conditioning particle size through milling, for example. Modification of both surface and bulk material structure will change the material properties, thus affecting the processability of the powder. Hence it is essential to control the material transformations that occur during milling. Topographical and mechanical changes in surface properties can be a preliminary indication of further material transformations. Therefore a surface evaluation of the alpha-lactose monohydrate after short and prolonged milling times has been performed. Unprocessed alpha-lactose monohydrate and spray dried lactose were evaluated in parallel to the milled samples as reference examples of the crystalline and amorphous lactose structure. Morphological differences between un-processed a-lactose, 1 h and 20 h milled lactose and spray dried lactose were detected from SEM and AFM images. Additionally, AFM was used to simultaneously characterize particle surface amorphicity by measuring energy dissipation. Extensive surface amorphicity was detected after 1 h of milling while prolonged milling times showed only a moderate particle surface amorphisation. Bulk material characterization performed with DSC indicated a partial amorphicity for the 1 h milled lactose and a fully amorphous thermal profile for the 20 h milled lactose. The temperature profiles however, were shifted somewhat in the comparison to the amorphous reference, particularly after extended milling, suggesting a different amorphous state compared to the spraydried material. Water loss during milling was measured with TGA, showing lower water content for the lactose amorphized through milling compared to spray dried amorphous lactose. The combined results suggest a surface-bulk propagation of the amorphicity during milling in combination with a different amorphous structural conformation to that of the amorphous spray dried lactose. The hardened surface may be due to either surface crystallization of lactose or to formation of a low-water glass transition.

  • 10.
    Baroffio, C. A.
    et al.
    Agroscope, Rte Eterpys 18, CH-1964 Conthey, Switzerland..
    Sigsgaard, L.
    Univ Copenhagen, Dept Plant & Environm Sci, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark..
    Ahrenfeldt, E. J.
    Univ Copenhagen, Dept Plant & Environm Sci, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark..
    Borg-Karlson, A. -K
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry.
    Bruun, S. A.
    NIBIO Norwegian Inst Bloecon Res, NO-1431 As, Norway.;NMBU Norwegian Univ Life Sci, Fac Environm Sci & Nat Resource Management, NO-1432 As, Norway..
    Cross, J. V.
    NIAB EMR, New Rd, Kent ME19 6BJ, England..
    Fountain, M. T.
    NIAB EMR, New Rd, Kent ME19 6BJ, England..
    Hall, D.
    Univ Greenwich, Nat Resources Inst, Cent Ave, Chatham ME4 4TB, Kent, England..
    Mozuraitis, R.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry.
    Ralle, B.
    LPPRC Latvian Plant Protect Res Ctr, Struktoru Lela 14 A, LV-1039 Riga, Latvia..
    Trandem, N.
    NIBIO Norwegian Inst Bloecon Res, NO-1431 As, Norway.;NMBU Norwegian Univ Life Sci, Fac Environm Sci & Nat Resource Management, NO-1432 As, Norway..
    Wibe, A.
    NORSOK Norwegian Ctr Organ Agr, Gunnars Vei 6, NO-6630 Tingvoll, Norway..
    Combining plant volatiles and pheromones to catch two insect pests in the same trap: Examples from two berry crops2018In: Crop Protection, ISSN 0261-2194, E-ISSN 1873-6904, Vol. 109, p. 1-8Article in journal (Refereed)
    Abstract [en]

    Most horticultural crops are attacked by more than one insect pest. As broad-spectrum chemical control options are becoming increasingly restricted, there is a need to develop novel control methods. Semiochemical attractants are available for three important horticultural pests, strawberry blossom weevil, Anthonomus rubi Herbst (Coleoptera: Curculionidae), European tarnished plant bug, Lygus rugulipennis Poppius (Hemiptera: Miridae) and raspberry beetle, Byturus tomentostts deGeer (Coleoptera: Byturidae). Traps targeting more than one pest species would be more practical and economical for both monitoring and mass trapping than traps for single-species. In this study we aimed to (1) improve the effectiveness of existing traps for insect pests in strawberry and raspberry crops by increasing catches of each species, and (2) test if attractants for two unrelated pest species could be combined to capture both in the same trap without decreasing the total catches. Field tests were carried out in four European countries and different combinations of semiochemicals were compared. A volatile from strawberry flowers, 1,4 dimethoxybenzene (DMB), increased the attractiveness of the aggregation pheromone to both sexes of A. rubi. The host-plant volatile, phenylacetaldehyde (PAA), increased the attraction of female L. rugulipennis to the sex pheromone, and, in strawberry, there was some evidence that adding DMB increased catches further. Traps baited with the aggregation pheromone of A. rubi, DMB, the sex pheromone of L rugulipennis and PAA attracted both target species to the same trap with no significant difference in catches compared to those single-species traps. In raspberry, catches in traps baited with a combination of A. rubi aggregation pheromone, DMB and the commercially available lure for B. tomentosus, based on raspberry flower volatiles, were similar to those in single-species traps. In both crops the efficiency of the traps still needs improvement, but the multi species traps are adequate for monitoring and should not lead to confusion for the user as the target species are easy to distinguish from each other.

  • 11.
    Berglund, Jennie
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Azhar, Shoaib
    Lawoko, Martin
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Lindström, Mikael
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Vilaplana, Francisco
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Wohlert, Jakob
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Henriksson, Gunnar
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    The structure of galactoglucomannan impactsthe degradation under alkaline conditions2018In: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882XArticle in journal (Refereed)
    Abstract [en]

    Galactoglucomannan (GGM) from sprucewas studied with respect to the degradation behavior inalkaline solution. Three reference systems includinggalactomannan from locust bean gum, glucomannanfrom konjac and the linear water-soluble carboxymethylcellulose were studied with focus onmolecular weight, sugar composition, degradationproducts, as well as formed oligomers, to identifyrelative structural changes in GGM. Initially allmannan polysaccharides showed a fast decrease inthe molecular weight, which became stable in the laterstage. The degradation of the mannan polysaccharidescould be described by a function corresponding to thesum of two first order reactions; one slow that wasascribed to peeling, and one fast that was connectedwith hydrolysis. The galactose side group wasstable under conditions used in this study (150 min,90 C, 0.5 M NaOH). This could suggest that, apartfrom the covalent connection to C6 in mannose, thegalactose substitutions also interact non-covalentlywith the backbone to stabilize the structure againstdegradation. Additionally, the combination of differentbackbone sugars seems to affect the stability of thepolysaccharides. For carboxymethyl cellulose thedegradation was linear over time which furthersuggests that the structure and sugar composition playan important role for the alkaline degradation. Moleculardynamics simulations gave details about theconformational behavior of GGM oligomers in watersolution, as well as interaction between the oligomersand hydroxide ions.

  • 12.
    Bernhem, Kristoffer
    et al.
    KTH, School of Engineering Sciences (SCI), Applied Physics. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Blom, H.
    KTH, Centres, Science for Life Laboratory, SciLifeLab. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry.
    Brismar, Hjalmar
    KTH, Centres, Science for Life Laboratory, SciLifeLab. KTH, School of Engineering Sciences (SCI), Applied Physics.
    Quantification of endogenous and exogenous protein expressions of Na,K-ATPase with super-resolution PALM/STORM imaging2018In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 13, no 4, article id e0195825Article in journal (Refereed)
    Abstract [en]

    Transient transfection of fluorescent fusion proteins is a key enabling technology in fluorescent microscopy to spatio-temporally map cellular protein distributions. Transient transfection of proteins may however bypass normal regulation of expression, leading to overexpression artefacts like misallocations and excess amounts. In this study we investigate the use of STORM and PALM microscopy to quantitatively monitor endogenous and exogenous protein expression. Through incorporation of an N-terminal hemagglutinin epitope to a mMaple3 fused Na,K-ATPase (α1 isoform), we analyze the spatial and quantitative changes of plasma membrane Na,K-ATPase localization during competitive transient expression. Quantification of plasma membrane protein density revealed a time dependent increase of Na,K-ATPase, but no increase in size of protein clusters. Results show that after 41h transfection, the total plasma membrane density of Na,K-ATPase increased by 63% while the endogenous contribution was reduced by 16%. © 2018 Bernhem et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

  • 13.
    Bhagavathiachari, Muthuraaman
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry.
    Elumalai, V.
    Gao, Jiajia
    KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Kloo, Lars
    KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Polymer-doped molten salt mixtures as a new concept for electrolyte systems in dye-sensitized solar cells2017In: ACS Omega, ISSN 2470-1343, Vol. 2, no 10, p. 6570-6575Article in journal (Refereed)
    Abstract [en]

    A conceptually new polymer electrolyte for dye-sensitized solar cells is reported and investigated. The benefits of using this type of electrolyte based on ionic liquid mixtures (ILMs) and room temperature ionic liquids are highlighted. Impedance spectroscopy and transient electron measurements have been used to elucidate the background of the photovoltaic performance. Even though larger recombination losses were noted, the high ion mobility and conductivity induced in the ILMs by the added polymer result in enhanced overall conversion efficiencies.

  • 14.
    Blomkvist, Björn
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry.
    Dinér, Peter
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry.
    HBF4 center dot DEE-catalyzed formation of sulfinyl imines: Synthesis and mechanistic studies2018In: Tetrahedron Letters, ISSN 0040-4039, E-ISSN 1359-8562, Vol. 59, no 13, p. 1249-1253Article in journal (Refereed)
    Abstract [en]

    A mild acid-catalysed method is reported for the formation of sulfinyl imines from tert-butanesulfinamide and aromatic or aliphatic aldehydes using tetrafluoroboric acid diethyletherate (10 mol%) in dichloromethane. Reactions were performed at room temperature and gave the corresponding sulfinyl imines in excellent yield after 2 h. A DFT study was performed and a mechanism for the reaction is postulated. 

  • 15.
    Busson, B.
    et al.
    Univ Paris Saclay, Univ Paris Sud, Lab Chim Phys, CNRS, Batiment 201 P2, F-91405 Orsay, France..
    Dalstein, Laetitia
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry. Univ Paris Saclay, Univ Paris Sud, Lab Chim Phys, CNRS, Batiment 201 P2, F-91405 Orsay, France.;KTH Royal Inst Technol, Dept Chem, Sch Chem Sci & Engn, SE-10044 Stockholm, Sweden.;Acad Sinica, Inst Phys, Taipei 11529, Taiwan..
    Nonlinear optical response of a gold surface in the visible range: A study by two-color sum-frequency generation spectroscopy. III. Simulations of the experimental SFG intensities2018In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 149, no 15, article id 154701Article in journal (Refereed)
    Abstract [en]

    We model the amplitude line shape and absolute phase of the infrared-visible sum-frequency signals produced by a thiolated polycrystalline gold surface as a function of the visible wavelength. We follow two hypotheses: in the interband scenario, the resonant features are attributed to interband transitions, whereas in the effective surface state scenario, they stem mostly from the excitation of surface transitions. We find that both scenarios lead to a satisfactory account of the experimental data and that only free electrons may spill out of the gold bulk, as expected. For the interband scenario, the balance between free and bound electron contributions to sum-frequency generation has to be adjusted to fit the data. The surface transitions are shown to take their origin inside gold and we investigate the surface states involved in such transitions, with a comparison to the silver surfaces. We finally provide a work program dedicated to discriminate between the two scenarios. Published by AIP Publishing.

  • 16.
    Cappellini, Francesca
    et al.
    Karolinska Inst, Inst Environm Med, Stockholm, Sweden..
    Hedberg, Yolanda
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science. Karolinska Inst, Inst Environm Med, Stockholm, Sweden.
    McCarrick, Sarah
    Karolinska Inst, Inst Environm Med, Stockholm, Sweden..
    Hedberg, Jonas
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Derr, Remco
    Toxys, Leiden, Netherlands..
    Hendriks, Giel
    Toxys, Leiden, Netherlands..
    Odnevall Wallinder, Inger
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Karlsson, Hanna L.
    Karolinska Inst, Inst Environm Med, Stockholm, Sweden..
    Mechanistic insight into reactivity and (geno)toxicity of well-characterized nanoparticles of cobalt metal and oxides2018In: Nanotoxicology, ISSN 1743-5390, E-ISSN 1743-5404, Vol. 12, no 6, p. 602-620Article in journal (Refereed)
    Abstract [en]

    An increasing use of cobalt (Co)-based nanoparticles (NPs) in different applications and exposures at occupational settings triggers the need for toxicity assessment. Improved understanding regarding the physiochemical characteristics of Co metal NPs and different oxides in combination with assessment of toxicity and mechanisms may facilitate decisions for grouping during risk assessment. The aim of this study was to gain mechanistic insights in the correlation between NP reactivity and toxicity of three different Co-based NPs (Co, CoO, and Co3O4) by using various tools for characterization, traditional toxicity assays, as well as six reporter cell lines (ToxTracker) for rapid detection of signaling pathways of relevance for carcinogenicity. The results showed cellular uptake of all NPs in lung cells and induction of DNA strand breaks and oxidative damage (comet assay) by Co and CoO NPs. In-depth studies on the ROS generation showed high reactivity of Co, lower for CoO, and no reactivity of Co3O4 NPs. The reactivity depended on the corrosion and transformation/dissolution properties of the particles and the media highlighting the role of the surface oxide and metal speciation as also confirmed by in silico modeling. By using ToxTracker, Co NPs were shown to be highly cytotoxic and induced reporters related to oxidative stress (Nrf2 signaling) and DNA strand breaks. Similar effects were observed for CoO NPs but at higher concentrations, whereas the Co3O4 NPs were inactive at all concentrations tested. In conclusion, our study suggests that Co and CoO NPs, but not Co3O4, may be grouped together for risk assessment.

  • 17.
    Chang, Tingru
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Atmospheric corrosion of copper and copper-based alloys in architecture: from native surface oxides to fully developed patinas2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Copper and copper-based alloys are commonly used in both ancient and modern architecture. This requires an in-depth fundamental and applied understanding on their atmospheric corrosion behavior at different climatic, environmental and pollutant levels and how these parameters influence e.g. corrosion initiation, patina characteristics, aesthetic appearances, corrosion rates, and runoff rates. This doctoral thesis elucidates the role of native surface oxides on the corrosion performance, corrosion initiation, formation and evolution of corrosion products from hours to months, years and even centuries, to diffuse dispersion of metals from Cu metal/Cu alloy surfaces focusing on the roles of alloying elements, microstructure, and deposition of chlorides. In-depth investigations have been performed at both laboratory and field conditions on commercial Cu metal and copper-based alloys of a golden alloy (Cu5Zn5Al1Sn) and Sn-bronzes (Cu4Sn, Cu6Sn). Patina characteristics and relations to the presence of microstructural inclusions have in addition been investigated for historic patinas of Cu metal roofing of different age and origin, highlighted with data for a 400 years old Cu patina exposed at urban conditions.

    A multi-analytical approach comprising microscopic, spectroscopic and electrochemical methods was employed for in-depth investigations of surface characteristics and bulk properties. Electron backscattered diffraction (EBSD) was utilized to characterize the microstructure. Auger electron spectroscopy (scanning-AES), X-ray photoelectron spectroscopy (XPS), glow discharge optical emission spectroscopy (GDOES) were employed for surface chemical compositional analysis, and atomic absorption spectroscopy (AAS) to assess the amount of metal release from the patinas. Cathodic reduction (CR) and electrochemical impedance spectroscopy (EIS) were used to assess the amount and corrosion resistance of corrosion products formed at laboratory conditions. Confocal Raman micro-spectroscopy (CRM), infrared reflection absorption spectroscopy (IRAS) and grazing incidence X-ray diffraction (GIXRD) were used to identify the phases of corrosion products. Colorimetry was used to assess surface appearances.

    Cu5Zn5Al1Sn and Cu4Sn/Cu6Sn exhibit favorable bulk properties with respect to corrosion in terms of smaller grain size compared with Cu metal and show non-significant surface compositional variations. The presence of multi-component native oxides predominantly composed of Cu2O enriched with Sn-oxides on Cu4Sn/Cu6Sn, and with ZnO, SnO2 and Al2O3 on Cu5Zn5Al1Sn, improves the barrier properties of the native surface oxides and the overall corrosion resistance of Cu4Sn/Cu6Sn and Cu5Zn5Al1Sn. The formation of Zn/Al/Sn-containing corrosion products (e.g. Zn5(CO3)2(OH)6 and Zn6Al2(OH)16CO3·4H2O) significantly reduces the corrosion rate of Cu5Zn5Al1Sn in chloride-rich environments. Alloying with Sn reduces the corrosion rate of Sn-bronze at urban environments of low chloride levels but results in enhanced corrosion rates at chloride-rich marine conditions.

    A clear dual-layer structure patina was observed for centuries-old naturally patinated copper metal with an origin from the roof of Queen Anne's Summer Palace in Prague, the Czech Republic. The patina comprises an inner sub-layer of Cu2O and an outer sub-layer of Cu4SO4(OH)6/Cu3SO4(OH)4. Abundant relatively noble inclusions (mainly rosiaite (PbSb2O6)) were observed and incorporated in both the copper matrix and the patina. The largest inclusions of higher nobility than the surrounding material create significant micro-galvanic effects that result in a fragmentized patina and large thickness ratios between the Cu4SO4(OH)6/Cu3SO4(OH)4 and the Cu2O sub-layer, investigated via a statistical analysis of inclusions and patina characteristics of eight different historic urban copper patinas.

  • 18.
    Chang, Tingru
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    The role of Sn on the long-term atmospheric corrosion of binary Cu-Sn bronze alloys in architectureManuscript (preprint) (Other academic)
  • 19.
    Chang, Tingru
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science. University of Science and Technology Beijing, China.
    Wallinder, Inger Odnevall
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Jin, Ying
    Leygraf, Christofer
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    The golden alloy Cu-5Zn-5Al-1Sn: A multi-analytical surface characterization2018In: Corrosion Science, ISSN 0010-938X, E-ISSN 1879-0496, Vol. 131, p. 94-103Article in journal (Refereed)
    Abstract [en]

    The golden alloy Cu-5Zn-5Al-1Sn has found many applications because of its appearance and resistance to tarnishing. The microstructure and multi-component surface oxide of Cu-5Zn-5Al-1Sn have been investigated through a multi-analytical approach. Compared to commercial Cu metal, Cu-5Zn-5Al-1Sn has significantly smaller grains and higher fraction of coherent twin boundaries. The 5-10 nm thick oxide formed after diamond polishing has four identified sub-oxides all contributing to the overall corrosion resistance. Cu2O is mainly located in the outer part, followed by ZnO, SnO2 and Al2O3 closer to the alloy substrate. The latter three possess barrier properties, while Cu2O exhibits a more complex structure.

  • 20. Chen, C.
    et al.
    Cheng, M.
    Li, H.
    Qiao, F.
    Liu, Peng
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry.
    Kloo, Lars
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry.
    Sun, Licheng
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry.
    Molecular engineering of ionic type perylenediimide dimer-based electron transport materials for efficient planar perovskite solar cells2018In: Materials Today Energy, ISSN 2468-6069, Vol. 9, p. 264-270Article in journal (Refereed)
    Abstract [en]

    The main of this work is to overcome the drawbacks of the traditional fullerene derivatives used as electron transport materials (ETMs) for perovskite solar cells (PSCs). Herein, a new strategy to design non-fullerene ETMs is presented by molecular engineering to include charged moieties in the ETM. The designed ETM FA2+-PDI2 is intrinsically ionic and the incorporated counter ions in FA2+-PDI2 significantly increase the electron conductivity and improve the film formation properties. Through careful device optimization, PSCs based on the ionic ETM FA2+-PDI2 exhibit an impressive average power conversion efficiency (PCE) of 17.0%, which is comparable to the PSC based on PC61BM (17.5%). The superior photovoltaic performance can be attributed to efficient electron extraction and effective electron transfer in the PSCs. This work provides important insights regarding the future design of new and efficient non-fullerene ETMs for PSCs. 

  • 21.
    Chen, Cheng
    et al.
    Jiangsu Univ, Inst Energy Res, Zhenjiang 212013, Peoples R China..
    Li, Hongping
    Jiangsu Univ, Inst Energy Res, Zhenjiang 212013, Peoples R China..
    Ding, Xingdong
    Jiangsu Univ, Inst Energy Res, Zhenjiang 212013, Peoples R China..
    Cheng, Ming
    Jiangsu Univ, Inst Energy Res, Zhenjiang 212013, Peoples R China..
    Li, Henan
    Jiangsu Univ, Sch Chem & Chem Engn, Zhenjiang 212013, Peoples R China..
    Xu, Li
    Jiangsu Univ, Inst Energy Res, Zhenjiang 212013, Peoples R China..
    Qiao, Fen
    Jiangsu Univ, Sch Energy & Power Engn, Zhenjiang 212013, Peoples R China..
    Li, Huaming
    Jiangsu Univ, Inst Energy Res, Zhenjiang 212013, Peoples R China..
    Sun, Licheng
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry.
    Molecular Engineering of Triphenylamine-Based Non-Fullerene Electron-Transport Materials for Efficient Rigid and Flexible Perovskite Solar Cells2018In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 10, no 45, p. 38970-38977Article in journal (Refereed)
    Abstract [en]

    There has been a growing interest in the design and synthesis of non-fullerene electron transport materials (ETMs) for perovskite solar cells (PSCs), which may overcome the drawbacks of traditional fullerene derivatives. In this work, a novel donor-acceptor (D-A) structured ETM termed TPA-3CN is presented by molecular engineering of triphenylamine (TPA) as the donor group and (3-cyano-4,5,5-trimethyl-2(5H)-furanylidene) malononitrile as the acceptor group. To further improve the electron mobility and conductivity and achieve excellent photovoltaic performance, a solution processable n-type dopant is introduced during the ETM spin-coating step. After device optimization, PSCs based on the doped TPA-3CN exhibit an impressive power conversion efficiency (PCE) of 19.2% with a negligible hysteresis. Benefitting from the low temperature and good solution processability of ETM TPA-3CN, it was further applied in flexible inverted PSCs and an impressive PCE of 13.2% was achieved, which is among the highest values reported for inverted flexible fullerene-free PSCs.

  • 22. Chen, H.
    et al.
    Gao, Y.
    Ye, L.
    Yao, Y.
    Chen, X.
    Wei, Y.
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry.
    A Cu2Se-Cu2O film electrodeposited on titanium foil as a highly active and stable electrocatalyst for the oxygen evolution reaction2018In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 54, no 39, p. 4979-4982Article in journal (Refereed)
    Abstract [en]

    Many nonprecious metal-selenide-based materials have been reported as electrocatalysts with high activity for the oxygen evolution reaction (OER). Herein, a hybrid catalyst film composed of Cu2Se and Cu2O nanoparticles directly grown on Ti foil (Cu2Se-Cu2O/TF) was prepared through a simple and fast cathodic electrodeposition method. Surprisingly, this electrode required a relatively low overpotential of 465 mV to achieve a catalytic current density of 10 mA cm-2 for the OER in 0.2 M carbonate buffer (pH = 11.0). Furthermore, a long-term constant current electrolysis test confirmed the high durability of the Cu2Se-Cu2O/TF anode at a current density of 10 mA cm-2 over 20 h. The XRD, TEM and XPS analysis of the sample after the OER indicated that a CuO protective layer formed on the surface of the Cu2Se-Cu2O catalyst, which effectively suppressed further oxidation of the Cu2Se-Cu2O catalyst during the OER and resulted in sustained catalytic oxidation of water.

  • 23.
    Chen, Song
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering.
    Abdel-Magied, Ahmed F.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering.
    Fu, Le
    Uppsala Universitet, Department of Engineering Sciences.
    Jonsson, Mats
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry.
    Forsberg, Kerstin
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering.
    Incorporation of strontium and europium in crystals of α-calcium isosaccharinate2019In: Journal of Hazardous Materials, ISSN 0304-3894, E-ISSN 1873-3336, Vol. 364, p. 309-316Article in journal (Refereed)
    Abstract [en]

    The final repository for short-lived, low and intermediate level radioactive waste in Sweden is built to act as a passive repository. Already within a few years after closure water will penetrate the repository and conditions of high alkalinity (pH 10.5―13.5) and low temperature (< 7 °C) will prevail. The mobility of radionuclides in the repository is dependent on the radionuclides distribution between solid and liquid phases. In the present work the incorporation of strontium (II) and europium (III) in α-calcium isosaccharinate (ISA) under alkaline conditions (pH ~10) at 5 °C and 50 °C have been studied. The results show that strontium and europium are incorporated into α-Ca(ISA)2 when crystallized both at 5 °C and 50 °C. Europium is incorporated to a greater extent than strontium. The highest incorporation of europium and strontium at 5 °C rendered the phase compositions Ca0.986Eu0.014(ISA)2 (2.4% of Eu(ISA)3 by mass) and Ca0.98Sr0.02(ISA)2 (2.2% of Sr(ISA)2 by mass). XPS spectra show that both trivalent and divalent Eu coexist in the Eu incorporated samples. Strontium ions were found to retard the elongated growth of the Ca(ISA)2crystals. The incorporation of Sr2+ and Eu3+ into the solid phase of Ca(ISA)2 is expected to contribute to a decreased mobility of these ions in the repository.

  • 24.
    Cheng, Jie
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science. Tsinghua University, Beijing, China.
    Pan, J.
    Wang, T.
    Lu, X.
    Micro-galvanic corrosion of Cu/Ru couple in potassium periodate (KIO4) solution2018In: Corrosion Science, ISSN 0010-938X, E-ISSN 1879-0496, Vol. 137, p. 184-193Article in journal (Refereed)
    Abstract [en]

    This paper focuses on the study of micro-galvanic corrosion of the Cu/Ru couple in KIO4 solution. Practical nobility across the Cu/Ru interface was evaluated by Volta potential mapping, and the morphological changes were monitored by in-situ atomic force microscopy measurements during exposure in a KIO4 solution. Chemical composition of precipitated corrosion product was analyzed by Confocal Raman spectroscopy immediately after the exposure. The results show that Cu is the anode of the Cu/Ru couple, and accelerated dissolution of Cu preferentially occurs near the Cu/Ru interface. However, subsequent formation of insoluble Cu(IO3)2·nH2O leads to precipitation, which impedes further Cu corrosion.

  • 25.
    Chernyshev, Alexander
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering.
    Forsberg, Kerstin
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering.
    Jonsson, Mats
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry.
    Impact of organic cement additives on the mobility of radionuclides in a radioactive waste repository2017Conference paper (Refereed)
  • 26.
    Chernyshev, Alexander N.
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering.
    Jonsson, Mats
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry.
    Forsberg, Kerstin
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering.
    Characterization and degradation of a polyaryl ether based superplasticizer for use in concrete barriers in deep geological repositories2018In: Applied Geochemistry, ISSN 0883-2927, E-ISSN 1872-9134, Vol. 95, p. 172-181Article in journal (Refereed)
    Abstract [en]

    Superplasticizers are important additives used in concrete barriers in geological waste repositories. Superplasticizers have been a major concern in the long-term assessments of safe geological disposal for radioactive waste since superplasticizers and their degradation products can act as complexing ligands and thereby increase the mobility of radionuclides. In this work a new type of superplasticizer, based on a polyaryl ether polymer, has been characterized. It was found that the superplasticizer combines the structural features of polycarboxylate ether based superplasticizers and sulfonated naphthalene-formaldehyde based superplasticizers and that it contains organophosphatecharged groups. A novel method for evaluating the rate of degradation of the superplasticizer under alkaline conditions was elaborated and the degradation products and rate constant of the process was determined. The results demonstrate that degradation occurs rapidly compared to the typical lifetime of a repository.

  • 27.
    Cifelli, M.
    et al.
    Univ Pisa, Dipartimento Chim & Chim Ind, I-56124 Pisa, Italy..
    Domenici, V.
    Univ Pisa, Dipartimento Chim & Chim Ind, I-56124 Pisa, Italy..
    Chizhik, V. I.
    St Petersburg State Univ, Dept Phys, St Petersburg 199034, Russia..
    Dvinskikh, Sergey
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry. St Petersburg State Univ, Lab Biomol NMR, St Petersburg 199034, Russia.
    N-15-C-13 Dipole Couplings in Smectic Mesophase of a Thermotropic Ionic Liquid2018In: Applied Magnetic Resonance, ISSN 0937-9347, E-ISSN 1613-7507, Vol. 49, no 6, p. 553-562Article in journal (Refereed)
    Abstract [en]

    Unique combination of ionic conductivity and anisotropic physical properties in ionic liquid crystals leads to new dynamic properties exploited in modern technological applications. Structural and dynamics information at atomic level for molecules and ions in mesophases can be obtained by nuclear magnetic resonance (NMR) spectroscopy through the measurements of dipole-dipole spin couplings. While C-13-H-1 and N-15-H-1 dipolar NMR spectra can be routinely acquired in samples with natural isotopic abundance, recording N-15-C-13 dipolar NMR spectra is challenging because of the unfavourable combination of two rare isotopes. In the present study, an approach to measure N-15-C-13 dipole-dipole NMR spectra in static liquid crystalline samples with natural abundance is introduced. We demonstrate that well-resolved spectra can be recorded within 10 h of experimental time using a conventional NMR probe and a moderately strong magnetic field. The technique is applied to a thermotropic smectic mesophase formed by an ionic liquid with imidazolium-based organic cation.

  • 28.
    Dai, Jing
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry. KTH Royal Inst Technol, Div Appl Phys Chem, Dept Chem, SE-10044 Stockholm, Sweden..
    Ferreira Fernandes, Ricardo Manuel
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry. KTH Royal Inst Technol, Div Appl Phys Chem, Dept Chem, SE-10044 Stockholm, Sweden.;Univ Porto, CIQUP, Dept Chem & Biochem, Fac Sci, P-4169007 Porto, Portugal..
    Regev, Oren
    Ben Gurion Univ Negev, Dept Chem Engn, IL-84105 Beer Sheva, Israel.;Ben Gurion Univ Negev, Ilse Katz Inst Nanotechnol, IL-84105 Beer Sheva, Israel..
    Marques, Eduardo F.
    Univ Porto, CIQUP, Dept Chem & Biochem, Fac Sci, P-4169007 Porto, Portugal..
    Furo, Istvan
    KTH, School of Chemical Science and Engineering (CHE), Centres, Industrial NMR Centre. KTH Royal Inst Technol, Div Appl Phys Chem, Dept Chem, SE-10044 Stockholm, Sweden..
    Dispersing Carbon Nanotubes in Water with Amphiphiles: Dispersant Adsorption, Kinetics, and Bundle Size Distribution as Defining Factors2018In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 122, no 42, p. 24386-24393Article in journal (Refereed)
    Abstract [en]

    Debundling and dispersing single-walled carbon nanotubes (SWNTs) is essential for applications, but the process is not well understood. In this work, aqueous SWNT dispersions were produced by sonicating pristine SWNT powder in the presence of an amphiphilic triblock copolymer (Pluronic F127) as dispersant. Upon centrifugation, one obtains a supernatant with suspended individual tubes and thin bundles and a precipitate with large bundles (and impurities). In the supernatant, that constitutes the final dispersion, we determined the dispersed SWNT concentration by thermogravi-metric analysis (TGA) and UV-vis spectroscopy, and the dispersant concentration by NMR The fraction of dispersant adsorbed at the SWNT surface was obtained by H-1 diffusion NMR Sigmoidal dispersion curves recording the concentration of dispersed SWNTs as a function of supernatant dispersant concentration were obtained at different SWNT loadings and sonication times. As SWNT bundles are debundled into smaller and smaller ones, the essential role of the dispersant is to sufficiently quickly cover the freshly exposed surfaces created by shear forces induced during sonication. Primarily kinetic reasons are behind the need for dispersant concentrations required to reach a substantial SWNT concentration. Centrifugation sets the size threshold below which SWNT particles are retained in the dispersion and consequently determines the SWNT concentration as a function of sonication time.

  • 29.
    Daniel, Quentin
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Duan, Lele
    KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Timmer, Brian J. J.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Chen, Hong
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Luo, Xiaodan
    Peking Univ, Coll Chem & Mol Engn, Beijing 100871, Peoples R China..
    Ambre, Ram
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Wang, Ying
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Zhang, Biaobiao
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Zhang, Peili
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry.
    Wang, Lei
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Li, Fusheng
    KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Sun, Junliang
    Peking Univ, Coll Chem & Mol Engn, Beijing 100871, Peoples R China..
    Ahlquist, Mårten S. G.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Theoretical Chemistry and Biology.
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry.
    Water Oxidation Initiated by In Situ Dimerization of the Molecular Ru(pdc) Catalyst2018In: ACS Catalysis, ISSN 2155-5435, E-ISSN 2155-5435, Vol. 8, no 5, p. 4375-4382Article in journal (Refereed)
    Abstract [en]

    The mononuclear ruthenium complex [Ru(pdc)L-3] (H(2)pdc = 2,6-pyridinedicarboxylic acid, L = N-heterocycles such as 4-picoline) has previously shown promising catalytic efficiency toward water oxidation, both in homogeneous solutions and anchored on electrode surfaces. However, the detailed water oxidation mechanism catalyzed by this type of complex has remained unclear. In order to deepen understanding of this type of catalyst, in the present study, [Ru(pdc)(py)(3)] (py = pyridine) has been synthesized, and the detailed catalytic mechanism has been studied by electrochemistry, UV-vis, NMR, MS, and X-ray crystallography. Interestingly, it was found that once having reached the Ru-IV state, this complex promptly formed a stable ruthenium dimer [Ru-III(pdc)(py)(2)-O-Ru-IV(pdc)(py)(2)](+). Further investigations suggested that the present dimer, after one pyridine ligand exchange with water to form [Ru-III(pdc)(py)(2)-O-Ru-IV(pdc)(py)(H2O)](+), was the true active species to catalyze water oxidation in homogeneous solutions.

  • 30.
    de Jesus, Liana Inara
    et al.
    Univ Fed Parana, Dept Biochem & Mol Biol, CP 19046, Curitiba, PR, Brazil..
    Smiderle, Fhernanda R.
    Univ Fed Parana, Dept Biochem & Mol Biol, CP 19046, Curitiba, PR, Brazil..
    Ruthes, Andrea C.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience.
    Vilaplana, Francisco
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Dal'Lin, Fernando Tonholi
    Univ Fed Parana, Dept Pharmacol, CP 19046, Curitiba, PR, Brazil..
    Maria-Ferreira, Daniele
    Univ Fed Parana, Dept Biochem & Mol Biol, CP 19046, Curitiba, PR, Brazil.;Univ Fed Parana, Dept Pharmacol, CP 19046, Curitiba, PR, Brazil..
    Werner, Maria Fernanda
    Univ Fed Parana, Dept Pharmacol, CP 19046, Curitiba, PR, Brazil..
    Van Griensven, Leo J. L. D.
    Wageningen Univ & Res, Plant Res Int, Bomsesteeg 1, NL-6708 PD Wageningen, Netherlands..
    Iacomini, Marcello
    Univ Fed Parana, Dept Biochem & Mol Biol, CP 19046, Curitiba, PR, Brazil..
    Chemical characterization and wound healing property of a beta-D-glucan from edible mushroom Piptoporus betulinus2018In: International Journal of Biological Macromolecules, ISSN 0141-8130, E-ISSN 1879-0003, Vol. 117, p. 1361-1366Article in journal (Refereed)
    Abstract [en]

    A water-soluble beta-D-glucan was obtained from fruiting bodies of Piptoporus betulinus, by hot aqueous extraction followed by freeze-thawing procedure and dialysis. Its molar mass distribution and conformational behavior in solution was assessed by size-exclusion chromatography coupled with multiangle laser light scattering, showing a polysaccharide with an average molecular weight of 2.5 x 10(5) Da with a random coil conformation for molecular weights below 1 x 10(6) Da. Typical signals of beta-(1 -> 3)-linkages were observed in NMR spectrum (delta 102.7/4.76; 102.8/4.74; 102.9/4.52; and delta 85.1/3.78; 85.0/3.77) and also signals of O-6 substitution at delta 69.2/4.22 and 69.2/3.87. The analysis of partially O-methylated alditol acetates corroborates the NMR results, indicating the presence of a beta-D-glucan with a main chain (1 -> 3)-linked, substituted at O-6 by single-units of glucose. The beta-D-glucan showed no toxicity on human colon carcinoma cell line (Caco-2) up to 1000 mu g mL(-1) and promoted cell migration on in vitro scratch assay, demonstrating a potential wound healing capacity.

  • 31.
    Di Bucchianico, Sebastiano
    et al.
    Karolinska Inst, Inst Environm Med, Stockholm, Sweden..
    Gliga, Anda R.
    Karolinska Inst, Inst Environm Med, Stockholm, Sweden..
    Åkerlund, Emma
    Karolinska Inst, Inst Environm Med, Stockholm, Sweden..
    Skoglund, Sara
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science. KTH Royal Inst Technol, Dept Chem Surface & Corros Sci, Stockholm, Sweden..
    Odnevall Wallinder, Inger
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Fadeel, Bengt
    Karolinska Inst, Inst Environm Med, Stockholm, Sweden..
    Karlsson, Hanna L.
    Karolinska Inst, Inst Environm Med, Stockholm, Sweden..
    Calcium-dependent cyto- and genotoxicity of nickel metal and nickel oxide nanoparticles in human lung cells2018In: Particle and Fibre Toxicology, ISSN 1743-8977, E-ISSN 1743-8977, Vol. 15, article id 32Article in journal (Refereed)
    Abstract [en]

    Background: Genotoxicity is an important toxicological endpoint due to the link to diseases such as cancer. Therefore, an increased understanding regarding genotoxicity and underlying mechanisms is needed for assessing the risk with exposure to nanoparticles (NPs). The aim of this study was to perform an in-depth investigation regarding the genotoxicity of well-characterized Ni and NiO NPs in human bronchial epithelial BEAS-2B cells and to discern possible mechanisms. Comparisons were made with NiCl2 in order to elucidate effects of ionic Ni. Methods: BEAS-2B cells were exposed to Ni and NiO NPs, as well as NiCl2, and uptake and cellular dose were investigated by transmission electron microscopy (TEM) and inductively coupled plasma mass spectrometry (ICP-MS). The NPs were characterized in terms of surface composition (X-ray photoelectron spectroscopy), agglomeration (photon cross correlation spectroscopy) and nickel release in cell medium (ICP-MS). Cell death (necrosis/apoptosis) was investigated by Annexin VFITC/PI staining and genotoxicity by cytokinesis-block micronucleus (cytome) assay (OECD 487), chromosomal aberration (OECD 473) and comet assay. The involvement of intracellular reactive oxygen species (ROS) and calcium was explored using the fluorescent probes, DCFH-DA and Fluo-4. Results: NPs were efficiently taken up by the BEAS-2B cells. In contrast, no or minor uptake was observed for ionic Ni from NiCl2. Despite differences in uptake, all exposures (NiO, Ni NPs and NiCl2) caused chromosomal damage. Furthermore, NiO NPs were most potent in causing DNA strand breaks and generating intracellular ROS. An increase in intracellular calcium was observed and modulation of intracellular calcium by using inhibitors and chelators clearly prevented the chromosomal damage. Chelation of iron also protected against induced damage, particularly for NiO and NiCl2. Conclusions: This study has revealed chromosomal damage by Ni and NiO NPs as well as Ni ionic species and provides novel evidence for a calcium-dependent mechanism of cyto- and genotoxicity.

  • 32.
    Du, Jian
    et al.
    Dalian Univ Technol, State Key Lab Fine Chem, DUT KTH Joint Educ & Res Ctr Mol Devices, Dalian 116024, Peoples R China..
    Li, Fei
    Dalian Univ Technol, State Key Lab Fine Chem, DUT KTH Joint Educ & Res Ctr Mol Devices, Dalian 116024, Peoples R China..
    Wang, Yong
    Dalian Univ Technol, State Key Lab Fine Chem, DUT KTH Joint Educ & Res Ctr Mol Devices, Dalian 116024, Peoples R China..
    Zhu, Yong
    Dalian Univ Technol, State Key Lab Fine Chem, DUT KTH Joint Educ & Res Ctr Mol Devices, Dalian 116024, Peoples R China..
    Sun, Licheng
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Organic chemistry. Dalian Univ Technol, State Key Lab Fine Chem, DUT KTH Joint Educ & Res Ctr Mol Devices, Dalian 116024, Peoples R China..
    Cu3P/CuO Core-Shell Nanorod Arrays as High-Performance Electrocatalysts for Water Oxidation2018In: Chemelectrochem, ISSN 2196-0216, Vol. 5, no 15, p. 2064-2068Article in journal (Refereed)
    Abstract [en]

    Earth-abundant transition-metal-based oxides are potential candidates to replace the state-of-the-art noble-metal-based oxygen evolution catalysts (OECs) such as IrO2 and RuO2. Despite the low cost and large abundance, copper-based OER catalysts have been less frequently studied, mainly owing to the low electrical conductivity of copper oxides that results in large overpotential and sluggish kinetics for oxygen evolution. We report here the insitu fabrication of semi-metallic Cu3P nanorod arrays on commercial copper foam via a template approach; the resulting self-supported core-shell Cu-Cu3P/CuO electrode has the merits of high electrical conductivity, large active area, and short diffusion paths for electrolyte and evolved oxygen, exhibiting a low overpotential of 315mV and high durability over 50h at a current density of 10mAcm(-2) for OER in 1.0 M KOH. The remarkable OER performance reported here is not only superior to that of analogous Cu-CuO foam electrode, but also outperforms those of copper-based OER electrocatalysts in the literature.

  • 33. Ekvall, Mikael T.
    et al.
    Hedberg, Jonas
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Wallinder, Inger Odnevall
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Hansson, Lars-Anders
    Cedervall, Tommy
    Long-term effects of tungsten carbide (WC) nanoparticles in pelagic and benthic aquatic ecosystems2018In: Nanotoxicology, ISSN 1743-5390, E-ISSN 1743-5404, Vol. 12, no 1, p. 79-89Article in journal (Refereed)
    Abstract [en]

    As the production and usage of nanomaterials are increasing so are the concerns related to the release of the material into nature. Tungsten carbide (WC) is widely used for its hard metal properties, although its use, in for instance tyre studs, may result in nano-sized particles ending up in nature. Here, we evaluate the potential long-term exposure effects of WC nanoparticles on a pelagic (Daphnia magna) and a benthic (Asellus aquaticus) organism. No long-term effects were observed in the benthic system with respect to population dynamics or ecosystem services. However, long-term exposure of D. magna resulted in increased time to first reproduction and, if the particles were resuspended, strong effects on survival and reproductive output. Hence, the considerable differences in acute vs. long-term exposure studies revealed here emphasize the need for more long-term studies if we are to understand the effects of nanoparticles in natural systems.

  • 34. Elawad, M.
    et al.
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry.
    Mola, G. T.
    Yu, Z.
    Arbab, E. A. A.
    Enhanced performance of perovskite solar cells using p-type doped PFB:F4TCNQ composite as hole transport layer2019In: Journal of Alloys and Compounds, ISSN 0925-8388, E-ISSN 1873-4669, Vol. 771, p. 25-32Article in journal (Refereed)
    Abstract [en]

    Conjugated polymers have been widely used as hole transport materials (HTM) in the preparation of mesoscopic perovskite solar cells (PSCs). In this work, we employed p-type doped conducting polymer known as poly(9,9-dioctylfluorene-co-bis-N,N-(-4-butyl phenyl)-bis-N,N-phenyl-1,4-phenylenediamine) (PFB) as a hole transport material (HTM) in perovskite based solar cell. The effect of dopant concentration on the optical and electrical properties of PEB was investigated to optimize the electrical properties of the material for the best function of the solar cell. The highest power conversion efficiency of mesoscopic perovskite solar cells (PSCs), fabricated in this investigation, was found to be 14.04% which is 57% higher than that of pristine PFB hole transport layer. The UV–Vis absorption and Raman spectroscopy measurements confirm the occurrence of oxidation in a p-type doped PFB hole transport layer. This is attributed to the transfer of electrons from the highest occupied molecular orbital (HOMO) of PEB to the lowest unoccupied molecular orbital (LUMO) of F4TCNQ. The solar cells produced using p-type doped PFB:F4TCNQ composite not only improves device performances but also shows superior long-term stability. The optical, morphological and electrical properties of the doped composite PFB: F4TCNQ and newly fabricated devices are presented and discussed in this paper.

  • 35.
    Elmhalli, Fawzeia
    et al.
    Uppsala Univ, Evolutionary Biol Ctr, Dept Systemat Biol, Norbyvagen 18d, SE-75236 Uppsala, Sweden..
    Pålsson, Katinka
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry.
    Orberg, Jan
    Uppsala Univ, Dept Environm Toxicol, Evolutionary Biol Ctr, Uppsala, Sweden..
    Grandi, Giulio
    Swedish Univ Agr Sci SLU, Dept Biomed Sci & Vet Publ Hlth, Uppsala, Sweden..
    Acaricidal properties of ylang-ylang oil and star anise oil against nymphs of Ixodes ricinus (Acari: Ixodidae)2018In: Experimental & applied acarology, ISSN 0168-8162, E-ISSN 1572-9702, Vol. 76, no 2, p. 209-220Article in journal (Refereed)
    Abstract [en]

    Ylang-ylang oil (YYO) from Cananga odorata (Lam.) Hook.f. & Thomson and star anise oil (SAO) from Illicium verum Hook.f. were tested at four concentrations 0.05, 0.1, 0.2, 0.4 mu l/cm(2). Mortality rates were obtained by counting dead nymphs at 30-min intervals during the first 5h after the start of exposure and then at 24, 48 and 72h. Mortality increased with increasing oil concentration and time of exposure. The two highest concentrations of YYO (0.2, 0.4 mu l/cm(2)) gave maximum lethal concentrations (LC) of 50 and 95% mortality after 4.5h exposure. Mortality of 95% was obtained after 24h with the next highest dose (0.1 mu l/cm(2)), whereas LC95 required 3days with the lowest YYO (0.05 mu l/cm(2)). The lethal effect time (LT) was correlated with the duration of exposure, with a significant effect at 0.4l YYO/cm(2) after 3h' (LT50=3.2h, LT95=4.3h). In contrast, only the highest concentration of SAO, 0.4 mu l SAO/cm(2), showed increasing mortality with time of exposure. This reached LT50 after 10h and LT95 after 24h. However, with the lower concentration (0.2 mu l/cm(2)) 50% mortality was reached after 24h and 100% at 72h. At to the lowest concentration of SAO (0.1 mu l/cm(2)), 67% mortality after 48h. The study indicates that YYO and SAO exhibit strong acaricidal properties against nymphs of I. ricinus and suggest that both YYO and SAO should be evaluated as potentially useful in the control of ticks.

  • 36.
    Elwinger, Fredrik
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry. GE Healthcare Biosci AB, Bjorkgatan 31, SE-75184 Uppsala, Sweden..
    Wernersson, Jonny
    GE Healthcare Biosci AB, Bjorkgatan 31, SE-75184 Uppsala, Sweden..
    Furo, Istvan
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry. GE Healthcare Biosci AB, Bjorkgatan 31, SE-75184 Uppsala, Sweden..
    Quantifying Size Exclusion by Diffusion NMR: A Versatile Method to Measure Pore Access and Pore Size2018In: Analytical Chemistry, ISSN 0003-2700, E-ISSN 1520-6882, Vol. 90, no 19, p. 11431-11438Article in journal (Refereed)
    Abstract [en]

    Size-exclusion quantification NMR spectroscopy (SEQNMR) is introduced for measuring equilibrium distribution coefficients, K-eq, in porous media. The porous medium is equilibrated with a polydisperse polymer solution. The original bulk polymer solution and the polymer solution after equilibration but in the absence of the porous medium are analyzed by NMR diffusion experiments. The joint evaluation of the two diffusion attenuation curves under suitable constraints provides the extent by which polymer fractions of particular size were depleted from the solution by pore access. This procedure yields K-eq versus polymer probe size, the selectivity curve that in turn can provide the pore size and its distribution. Simulations probe the performance of the method that is demonstrated experimentally in chromatographic media using dextran polymers. SEQ-NMR and inverse size- exclusion chromatography (ISEC) yield selectivity curves that virtually coincide. Crucial advantages with SEQ-NMR, such as versatility with regard to both the polymer used and porous system explored, high speed, potential for automation, and small required sample volume, are discussed.

  • 37.
    Forsberg, Kerstin
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering.
    Rodríguez Varela, Raquel
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering.
    Martínez, Joaquin
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering.
    Kloo, Lars
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry.
    Rasmuson, Åke C.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering.
    Processing of a rare earth element concentrate by hollow fibre supported liquid membrane extraction2017Conference paper (Refereed)
  • 38.
    Gatty, M. Gilbert
    et al.
    Uppsala Univ, Dept Chem, Angstrom Lab, Phys Chem, Box 523, S-75120 Uppsala, Sweden..
    Pullen, S.
    Uppsala Univ, Dept Chem, Angstrom Lab, Phys Chem, Box 523, S-75120 Uppsala, Sweden..
    Sheibani, Esmaeil
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Organic chemistry.
    Tian, H.
    Uppsala Univ, Dept Chem, Angstrom Lab, Phys Chem, Box 523, S-75120 Uppsala, Sweden..
    Ott, S.
    Uppsala Univ, Dept Chem, Angstrom Lab, Phys Chem, Box 523, S-75120 Uppsala, Sweden..
    Hammarstrom, L.
    Uppsala Univ, Dept Chem, Angstrom Lab, Phys Chem, Box 523, S-75120 Uppsala, Sweden..
    Direct evidence of catalyst reduction on dye and catalyst co-sensitized NiO photocathodes by mid-infrared transient absorption spectroscopy2018In: Chemical Science, ISSN 2041-6520, E-ISSN 2041-6539, Vol. 9, no 22, p. 4983-4991Article in journal (Refereed)
    Abstract [en]

    Co-sensitization of molecular dyes and catalysts on semiconductor surfaces is a promising strategy to build photoelectrodes for solar fuel production. In such a photoelectrode, understanding the charge transfer reactions between the molecular dye, catalyst and semiconductor material is key to guide further improvement of their photocatalytic performance. Herein, femtosecond mid-infrared transient absorption spectroscopy is used, for the first time, to probe charge transfer reactions leading to catalyst reduction on co-sensitized nickel oxide (NiO) photocathodes. The NiO films were co-sensitized with a molecular dye and a proton reducing catalyst from the family of [FeFe](bdt)(CO)(6) (bdt = benzene-1,2-dithiolate) complexes. Two dyes were used: an organic push-pull dye denoted E2 with a triarylamine-oligothiophene-dicyanovinyl structure and a coumarin 343 dye. Upon photo-excitation of the dye, a clear spectroscopic signature of the reduced catalyst is observed a few picoseconds after excitation in all co-sensitized NiO films. However, kinetic analysis of the transient absorption signals of the dye and reduced catalyst reveal important mechanistic differences in the first reduction of the catalyst depending on the co-sensitized molecular dye (E2 or C343). While catalyst reduction is preceded by hole injection in NiO in C343-sensitized NiO films, the singly reduced catalyst is formed by direct electron transfer from the excited dye E2* to the catalyst in E2-sensitized NiO films. This change in mechanism also impacts the lifetime of the reduced catalyst, which is only ca. 50 ps in E2-sensitized NiO films but is >5 ns in C343-sensitized NiO films. Finally, the implication of this mechanistic study for the development of better co-sensitized photocathodes is discussed.

  • 39.
    Geng, Shiyu
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology. Luleå Univ Technol, Div Mat Sci, Dept Engn Sci & Math, SE-97187 Luleå, Sweden.
    Yao, Kun
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience.
    Zhou, Qi
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Oksman, Kristiina
    Luleå Univ Technol, Div Mat Sci, Dept Engn Sci & Math, SE-97187 Luleå, Sweden.;Univ Oulu, Fibre & Particle Engn, FI-90014 Oulu, Finland..
    High-Strength, High-Toughness Aligned Polymer-Based Nanocomposite Reinforced with Ultralow Weight Fraction of Functionalized Nanocellulose2018In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 19, no 10, p. 4075-4083Article in journal (Refereed)
    Abstract [en]

    Multifunctional lightweight, flexible, yet strong polymer-based nanocomposites are highly desired for specific applications. However, the control of orientation and dispersion of reinforcing nanoparticles and the optimization of the interfacial interaction still pose substantial challenges in nanocellulose-reinforced polymer composites. In this study, poly(ethylene glycol) (PEG)-grafted cellulose nanofibers have demonstrated much better dispersion in a poly(lactic acid) (PLA) matrix as compared to unmodified nanocellulose. Through a uniaxial drawing method, aligned PLA/nanocellulose nanocomposites with high strength, high toughness, and unique optical behavior can be obtained. With the incorporation of 0.1 wt % of the PEG-grafted cellulose nanofibers in PLA, the ultimate strength of the aligned nanocomposite reaches 343 MPa, which is significantly higher than that of other aligned PLA-based nanocomposites reported previously. Moreover, its ultimate strength and toughness are enhanced by 39% and 70%, respectively, as compared to the aligned nanocomposite reinforced with unmodified cellulose nanofibers. In addition, the aligned nanocomposite film is highly transparent and possesses an anisotropic light scattering effect, revealing its significant potential for optical applications.

  • 40.
    Ghamgosar, Pedram
    et al.
    Lulea Univ Technol, Div Mat Sci, Dept Engn Sci & Math, S-97187 Lulea, Sweden..
    Rigoni, Federica
    Lulea Univ Technol, Div Mat Sci, Dept Engn Sci & Math, S-97187 Lulea, Sweden..
    You, Shujie
    Lulea Univ Technol, Div Mat Sci, Dept Engn Sci & Math, S-97187 Lulea, Sweden..
    Dobryden, Illia
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Kohan, Mojtaba Gilzad
    Lulea Univ Technol, Div Mat Sci, Dept Engn Sci & Math, S-97187 Lulea, Sweden..
    Pellegrino, Anna Lucia
    Univ Catania, Dipartimento Sci Chim, INSTM UdR Catania, Viale A Doria 6, I-95125 Catania, Italy..
    Concina, Isabella
    Lulea Univ Technol, Div Mat Sci, Dept Engn Sci & Math, S-97187 Lulea, Sweden..
    Almqvist, Nils
    Lulea Univ Technol, Div Mat Sci, Dept Engn Sci & Math, S-97187 Lulea, Sweden..
    Malandrino, Graziella
    Univ Catania, Dipartimento Sci Chim, INSTM UdR Catania, Viale A Doria 6, I-95125 Catania, Italy..
    Vomiero, Alberto
    Lulea Univ Technol, Div Mat Sci, Dept Engn Sci & Math, S-97187 Lulea, Sweden..
    ZnO-Cu2O core-shell nanowires as stable and fast response photodetectors2018In: Nano Energy, ISSN 2211-2855, E-ISSN 2211-3282, Vol. 51, p. 308-316Article in journal (Refereed)
    Abstract [en]

    In this work, we present all-oxide p-n junction core-shell nanowires (NWs) as fast and stable self-powered photodetectors. Hydrothermally grown n-type ZnO NWs were conformal covered by different thicknesses (up to 420 nm) of p-type copper oxide layers through metalorganic chemical vapor deposition (MOCVD). The ZnO NWs exhibit a single crystalline Wurtzite structure, preferentially grown along the [002] direction, and energy gap E-g = 3.24 eV. Depending on the deposition temperature, the copper oxide shell exhibits either a crystalline cubic structure of pure Cu2O phase (MOCVD at 250 degrees C) or a cubic structure of Cu2O with the presence of CuO phase impurities (MOCVD at 300 degrees C), with energy gap of 2.48 eV. The electrical measurements indicate the formation of a p-n junction after the deposition of the copper oxide layer. The core-shell photodetectors present a photo-responsivity at 0 V bias voltage up to 7.7 mu A/W and time response <= 0.09 s, the fastest ever reported for oxide photodetectors in the visible range, and among the fastest including photodetectors with response limited to the UV region. The bare ZnO NWs have slow photoresponsivity, without recovery after the end of photo-stimulation. The fast time response for the core-shell structures is due to the presence of the p-n junctions, which enables fast exciton separation and charge extraction. Additionally, the suitable electronic structure of the ZnO-Cu2O heterojunction enables self-powering of the device at 0 V bias voltage. These results represent a significant advancement in the development of low-cost, high efficiency and self-powered photodetectors, highlighting the need of fine tuning the morphology, composition and electronic properties of p-n junctions to maximize device performances.

  • 41.
    Gustafsson, Camilla
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry.
    Vassiliev, Serguei
    Department of Biological Sciences, Brock University, Ontario, Canada.
    Kürten, Charlotte
    KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Syrén, Per-Olof
    KTH, Centres, Science for Life Laboratory, SciLifeLab. KTH, School of Biotechnology (BIO), Proteomics and Nanobiotechnology.
    Brinck, Tore
    MD Simulations Reveal Complex Water Paths in Squalene–Hopene Cyclase: Tunnel-Obstructing Mutations Increase the Flow of Water in the Active Site2017In: ACS Omega, ISSN 2470-1343, Vol. 2, no 11, p. 8495-8506Article in journal (Refereed)
    Abstract [en]

    Squalene–hopene cyclase catalyzes the cyclization of squalene to hopanoids. A previous study has identified a network of tunnels in the protein, where water molecules have been indicated to move. Blocking these tunnels by site-directed mutagenesis was found to change the activation entropy of the catalytic reaction from positive to negative with a concomitant lowering of the activation enthalpy. As a consequence, some variants are faster and others are slower than the wild type (wt) in vitro under optimal reaction conditions for the wt. In this study, molecular dynamics (MD) simulations have been performed for the wt and the variants to investigate how the mutations affect the protein structure and the water flow in the enzyme, hypothetically influencing the activation parameters. Interestingly, the tunnel-obstructing variants are associated with an increased flow of water in the active site, particularly close to the catalytic residue Asp376. MD simulations with the substrate present in the active site indicate that the distance for the rate-determining proton transfer between Asp376 and the substrate is longer in the tunnel-obstructing protein variants than in the wt. On the basis of the previous experimental results and the current MD results, we propose that the tunnel-obstructing variants, at least partly, could operate by a different catalytic mechanism, where the proton transfer may have contributions from a Grotthuss-like mechanism.

  • 42. Hagman, H.
    et al.
    Lundberg, Mats
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Boström, D.
    Alloy Selection for a Cofired Circulating Fluidized Bed Boiler Vortex Finder Application at 880 °c in a Complex Mixed Mode Corrosion Environment2017In: Energy & Fuels, ISSN 0887-0624, E-ISSN 1520-5029, Vol. 31, no 11, p. 12857-12866Article in journal (Refereed)
    Abstract [en]

    X-ray diffraction and scanning electron microscopy (SEM) were used on a corroded industrial-scale circulating fluidized bed (CFB) boiler vortex finder (VF) 253MA alloy plate material to identify the dominating corrosion products and to enable a qualified selection of candidate alloys for the long-term, full-scale exposure study. Alloys 253MA, 310S, 800H/HT, Alloy DS, and Alloy 600 were chosen, and the alloy plates were exposed to the CFB boiler combustion atmosphere having an average temperature of approximately 880 °C, consisting of a moist globally oxidizing gas, burning hydrocarbons, CO2, CO, SO2, HCl, NH3, N2, alkali species, and erosive particles. The exposure times used in this study were 1750, 8000, 12000, and 16000 operating hours. After exposure, the alloy samples were cut, and cross-sections were dry-polished and analyzed with an SEM-backscatter electron detector (BSD) setup to quantify material loss and penetration depth of the corrosion attack. This work suggests two novel concepts: heavily affected depth (HAD) enabling quantitative evaluation of heavily degraded alloys and remaining serviceable metal thickness (RSMT) enabling the use of long-term corrosion data from one alloy to make rough service life estimations of other alloys exposed for significantly shorter periods. The findings of this work show that there is no simple correlation between the heavily affected depth of the alloy and the nickel, chromium, or iron content. Instead, there seem to be two successful alloy composition principles that work well for this application. Furthermore, the work shows that major improvements can be made in terms of both technical life-span and the cost-effectiveness of the VF application if the most appropriate alloy is selected. In this study, a replacement of the frequently used Alloy 253MA with Alloy 310S doubled the lifespan of full-scale VFs, reducing the average VF maintenance cost to half.

  • 43.
    Hao, Yan
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry.
    Yang, Wenxing
    Uppsala Univ, Dept Chem, Angstrom Lab, Phys Chem, SE-75120 Uppsala, Sweden.;Emory Univ, Dept Chem, 1515 Dickey Dr NE, Atlanta, GA 30322 USA..
    Karlsson, Karl Martin
    KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Cong, Jiayan
    KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Wang, Shihuai
    Uppsala Univ, Dept Chem, Angstrom Lab, Phys Chem, SE-75120 Uppsala, Sweden..
    Lo, Xing
    East China Univ Sci & Technol, Inst Fine Chem, Sch Chem & Mol Engn, Key Lab Adv Mat, Shanghai 200237, Peoples R China..
    Xu, Bo
    Uppsala Univ, Dept Chem, Angstrom Lab, Phys Chem, SE-75120 Uppsala, Sweden..
    Hua, Jianli
    East China Univ Sci & Technol, Inst Fine Chem, Sch Chem & Mol Engn, Key Lab Adv Mat, Shanghai 200237, Peoples R China..
    Kloo, Lars
    KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Boschloo, Gerrit
    Uppsala Univ, Dept Chem, Angstrom Lab, Phys Chem, SE-75120 Uppsala, Sweden..
    Efficient Dye-Sensitized Solar Cells with Voltages Exceeding 1 V through Exploring Tris(4-alkoxyphenyl)amine Mediators in Combination with the Tris(bipyridine) Cobalt Redox System2018In: ACS ENERGY LETTERS, ISSN 2380-8195, Vol. 3, no 8, p. 1929-1937Article in journal (Refereed)
    Abstract [en]

    Tandem redox electrolytes, prepared by the addition of a tris(p-anisyl)amine mediator into classic tris(bipyridine)cobalt-based electrolytes, demonstrate favorable electron transfer and reduced energy loss in dye-sensitized solar cells. Here, we have successfully explored three tris(4-alkoxyphenyl)-amine mediators with bulky molecular structures and generated more effective tandem redox systems. This series of tandem redox electrolytes rendered solar cells with very high photovoltages exceeding 1 V, which approaches the theoretical voltage limit of tris(bipyridine)cobalt-based electrolytes. Solar cells with power conversion efficiencies of 9.7-11.0% under 1 sun illumination were manufactured. This corresponds to an efficiency improvement of up to 50% as compared to solar cells based on pure tris(bipyridine)cobalt-based electrolytes. The photovoltage increases with increasing steric effects of the tris(4-alkoxyphenyl)amine mediators, which is attributed to a retarded recombination kinetics. These results highlight the importance of structural design for optimized charge transfer at the sensitized semiconductor/electrolyte interface and provide insights for the future development of efficient dye-sensitized solar cells.

  • 44.
    Hariramabadran Anantha, Krishnan
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    An Experimental Study to Understand the Localized Corrosion and Environment-Assisted Cracking Behavior of AISI 420-Martensitic Stainless Steel2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Motivation and aim: Currently steel molds are designed with cooling channels to reduce the solidification time of molten plastic within the mold to improve the productivity. As water is generally used as the cooling medium, corrosion and environment-assisted cracking (EAC) leading towards the dysfunction of mold, can increase the production downtime. This was observed in some cases. Hence the primary aim of this thesis is to study the corrosion and EAC behavior of a martensitic stainless steel (MSS) in Cl containing environment to further the current understanding thereby to optimize the existing alloy/s and to design and develop new steel grades.

    Methods: The MSS had been austenitised at 1020°C, and subsequently quenched in nitrogen gas at fast (3°C/s), and slow quenching rates (0.6°C/s). Then tempering was done at 250°C, and 500°C, respectively, twice for two hours. Microstructure was predicted and characterized using Thermocalc simulation, dilatometry, light optical microscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, atomic force microscopy (AFM). Localized corrosion behavior was characterized using standard salt spray test, electrochemical experiments, scanning Kelvin probe force microscopy, in-situ AFM. Stress relaxation associated with 250°C, and 500°C tempering was characterized by a new method for both fast (FQ) and slow quenched (SQ) conditions. Based on the %stress relaxation, initial loading levels were altered and the corresponding environment-assisted cracking behavior was investigated at two different loading levels.

    Results: Samples tempered at 250ºC exhibited higher corrosion resistance than samples tempered at 500ºC in both FQ and SQ conditions. FQ samples exhibited higher corrosion resistance with an ability to passivate than SQ samples when tempered at 250ºC. However, when tempered at 500°C, the corrosion resistance was poor for both FQ and SQ samples. These observed differences clearly indicate the strong influence of microstructure on the corrosion behavior of the material. There are preferential active sites in the microstructure, which dictate the sequence of corrosion events. Secondary Cr-rich carbides formed during 500ºC tempering apparently deteriorate the corrosion resistance in spite of their smaller sizes as compared to undissolved Cr-rich carbides.  Stress relaxation increased with increasing tempering temperature. In the FQ condition, 250°C temper exhibited superior EAC resistance than 500°C temper in both loading scenarios, indicating the dominant role of corrosion resistance in delaying the failure. Whereas in SQ condition, 500°C temper exhibited superior EAC resistance than 250°C temper in both loading scenarios, indicating the dominant role of applied stress in delaying the failure. The pitting susceptibility increased with increasing applied stress on both FQ and SQ conditions. The fractographic features suggest that the mechanism of failure was mixed mode involving both active path dissolution and hydrogen embrittlement, which could have been operative during the failure in varying magnitude in respective scenarios. 

    Conclusions: Based on this research work, it can be concluded that, in order to have a longer service life, both the localized corrosion behavior and the residual stresses are to be considered while recommending tempering temperature to mold makers.

  • 45.
    Hariramabadran Anantha, Krishnan
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Ejnermark, Sebastian
    Medvedeva, Anna
    Sjöström, Johnny
    Pan, Jinshan
    Corrosion Behavior of a Martensitic Stainless Steel AISI 420 Modified From a Mold Size Point of View2016Conference paper (Refereed)
  • 46.
    Hariramabadran Anantha, Krishnan
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Örnek, Cem
    Ejnermark, Sebastian
    Medvedeva, Anna
    Sjöström, Johnny
    Pan, Jinshan
    Effect of residual stress on environmentally assisted cracking behavior of slow quenched AISI 420martensitic stainless steel tempered at 250°C and 500°CManuscript (preprint) (Other academic)
  • 47.
    Hariramabadran Anantha, Krishnan
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Örnek, Cem
    Ejnermark, Sebastian
    Thuvander, Anders
    Medvedeva, Anna
    Sjöström, Johnny
    Pan, Jinshan
    Experimental and modelling study of the effects of tempering on the susceptibility to environment-assisted cracking of AISI 420 martensitic stainless steelManuscript (preprint) (Other academic)
  • 48. Harriman, Anthony
    et al.
    Inoue, Haruo
    Sun, Licheng
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Organic chemistry.
    Capturing the Light Fantastic2018In: Chemphotochem, ISSN 2367-0932, Vol. 2, no 3, p. 110-111Article in journal (Refereed)
  • 49.
    He, Yunjuan
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Dobryden, Illia
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Pan, Jinshan
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Ahniyaz, Anwar
    RISE Res Inst Sweden, Div Biosci & Mat, SE-11486 Stockholm, Sweden..
    Deltin, Tomas
    PTE Coatings AB, Hammarsvagen 4, SE-59432 Gamleby, Sweden..
    Corkery, Robert W.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Claesson, Per M.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Nano-scale mechanical and wear properties of a waterborne hydroxyacrylic-melamine anti-corrosion coating2018In: Applied Surface Science, ISSN 0169-4332, E-ISSN 1873-5584, Vol. 457, p. 548-558Article in journal (Refereed)
    Abstract [en]

    Corrosion protection is commonly achieved by applying a thin polymer coating on the metal surface. Many studies have been devoted to local events occurring at the metal surface leading to local or general corrosion. In contrast, changes occurring in the organic coating after exposure to corrosive conditions are much less studied. In this article we outline how changes in the coating itself due to curing conditions, environmental and erosion effects can be investigated at the nanometer scale, and discuss how such changes would affect its corrosion protection performance. We focus on a waterborne hydroxyacrylic-melamine coating, showing high corrosion protection performance for carbon steel during long-term (approximate to 35 days) exposure to 0.1 M NaCl solution. The effect of curing time on the conversion of the crosslinking reaction within the coating was evaluated by fourier transform infrared spectroscopy (FTIR); the wetting properties of the cured films were investigated by contact angle measurement, and the corrosion resistance was studied by electrochemical impedance spectroscopy (EIS). In particular, coating nanomechanical and wear properties before and after exposure to 0.1 M NaCl, were evaluated by atomic force microscopy (AFM). Fiber-like surface features were observed after exposure, which are suggested to arise due to diffusion of monomers or low molecular weight polymers to the surface. This may give rise to local weakening of the coating, leading to local corrosion after even longer exposure times. We also find a direct correlation between the stick-slip spacing during shearing and plastic deformation induced in the surface layer, giving rise to topographical ripple structures on the nanometer length scale.

  • 50.
    Hedberg, Yolanda
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science. Institute of Environmental Medicine, Karolinska Institute, Stockholm, Sweden.
    Erfani, Behnaz
    Institute of Environmental Medicine, Karolinska Institute, Stockholm, Sweden.
    Matura, Mihály
    Institute of Environmental Medicine, Karolinska Institute, Stockholm, Sweden ; Unit of Occupational and Environmental Dermatology, Centre for Occupational and Environmental Medicine, Stockholm County Council, Stockholm, Sweden.
    Lidén, Carola
    Institute of Environmental Medicine, Karolinska Institute, Stockholm, Sweden.
    Chromium(III) release from chromium-tanned leather elicits allergic contact dermatitis: a use test study.2018In: Contact Dermatitis, ISSN 0105-1873, E-ISSN 1600-0536, Vol. 78, no 5, p. 307-314Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Chromium (Cr) is a common skin sensitizer. The use of Cr(VI) in leather is restricted in the EU, but that of Cr(III) is not.

    OBJECTIVES: To assess whether prolonged exposure to Cr-tanned leather with mainly Cr(III) release may elicit allergic contact dermatitis in Cr-allergic individuals.

    METHOD: Ten Cr-allergic subjects and 22 controls were patch tested with serial dilutions of Cr(III) and Cr(VI), and with leather samples. They then conducted a use test with a Cr-tanned and a Cr-free leather bracelet over a period of 3 weeks, for 12 h per day. Cr deposited on the skin from the bracelets was measured in the controls, and the diphenylcarbazide test for Cr(VI) and extraction tests for Cr(III) and Cr(VI) were conducted for the different leathers.

    RESULTS: Four of 10 Cr-allergic subjects developed positive reactions to the Cr-tanned bracelet within 7-21 days, whereas only 1 of 10 had a positive patch test reaction to this leather. Cr released from the Cr-tanned leather was most probably entirely Cr(III), with a quantifiable amount being deposited on the skin.

    CONCLUSIONS: This study strongly suggests that prolonged and repeated exposure to Cr-tanned leather with mainly Cr(III) release is capable of eliciting allergic contact dermatitis in Cr-allergic individuals.

1234 1 - 50 of 180
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf