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  • 1.
    Almhöjd, Ulrika S.
    et al.
    Sahlgrenska Academy, Sweden.
    Lingström, Peter
    Sahlgrenska Academy, Sweden.
    Nilsson, Åke
    Sahlgrenska Academy, Sweden.
    Noren, Jörgen G.
    Sahlgrenska Academy, Sweden.
    Siljeström, Silje
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry, Materials and Surfaces.
    ֖stlund, Å.
    RISE - Research Institutes of Sweden, Bioeconomy, Biorefinery and Energy.
    Bernin, D.
    University of Gothenburg, Sweden.
    Molecular Insights into Covalently Stained Carious Dentine Using Solid-State NMR and ToF-SIMS2017In: Caries Research, ISSN 0008-6568, E-ISSN 1421-976X, Vol. 51, no 3, p. 255-263Article in journal (Refereed)
    Abstract [en]

    Dyes currently used to stain carious dentine have a limited capacity to discriminate normal dentine from carious dentine, which may result in overexcavation. Consequently, finding a selective dye is still a challenge. However, there is evidence that hydrazine-based dyes, via covalent bonds to functional groups, bind specifically to carious dentine. The aim of this study was to investigate the possible formation of covalent bonds between carious dentine and 15N2-hydrazine and the hydrazine-based dye, 15N2-labelled Lucifer Yellow, respectively. Powdered dentine from extracted carious and normal teeth was exposed to the dyes, and the staining reactions were analysed using time-of-flight secondary ion mass spectrometry (ToF-SIMS), solid-state 13C-labelled nuclear magnetic resonance (NMR) and 15N-NMR spectroscopy. The results showed that 15N2-hydrazine and 15N2-labelled Lucifer Yellow both bind to carious dentine but not to normal dentine. It can thus be concluded that hydrazine-based dyes can be used to stain carious dentine and leave normal dentine unstained.

  • 2.
    An, Jungxue
    et al.
    KTH Royal Institute of Technology, Sweden.
    Jin, Chunsheng
    Sahlgrenska Academy, Sweden ; University of Gothenburg, Sweden.
    Dėdinaitė, Andra
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry, Materials and Surfaces. KTH Royal Institute of Technology, Sweden.
    Holgersson, Jan
    Sahlgrenska Academy, Sweden ; University of Gothenburg, Sweden.
    Karlsson, Niclas G.
    Sahlgrenska Academy, Sweden ; University of Gothenburg, Sweden.
    Claesson, Per M.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry, Materials and Surfaces. KTH Royal Institute of Technology, Sweden.
    Influence of Glycosylation on Interfacial Properties of Recombinant Mucins: Adsorption, Surface Forces, and Friction2017In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 33, no 18, p. 4386-4395Article in journal (Refereed)
    Abstract [en]

    Interfacial properties of two brush-with-anchor mucins, C-P55 and C-PSLex, have been investigated at the aqueous solution/poly(methyl methacrylate) (PMMA) interface. Both are recombinant mucin-type fusion proteins, produced by fusing the glycosylated mucin part of P-selectin glycoprotein ligand-1 (PSLG-1) to the Fc part of a mouse immunoglobulin in two different cells. They are mainly expressed as dimers upon production. Analysis of the O-glycans shows that the C-PSLex mucin has the longer and more branched side chains, but C-P55 has slightly higher sialic acid content. The adsorption of the mucins to PMMA surfaces was studied by quartz crystal microbalance with dissipation. The sensed mass, including the adsorbed mucin and water trapped in the layer, was found to be similar for these two mucin layers. Atomic force microscopy with colloidal probe was employed to study surface and friction forces between mucin-coated PMMA surfaces. Purely repulsive forces of steric origin were observed between mucin layers on compression, whereas a small adhesion was detected between both mucin layers on decompression. This was attributed to chain entanglement. The friction force between C-PSLex-coated PMMA is lower than that between C-P55-coated PMMA at low loads, but vice versa at high loads. We discuss our results in terms of the differences in the glycosylation composition of these two mucins.

  • 3.
    An, Junxue
    et al.
    KTH Royal Institute of Technology, Sweden.
    Liu, Xiaoyan
    KTH Royal Institute of Technology, Sweden.
    Dedinaite, Andra
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry, Materials and Surfaces. KTH Royal Institute of Technology, Sweden.
    Korchagina, Evgeniya
    University of Montreal, Canada .
    Winnik, Francoise M.
    University of Montreal, Canada ; National Institute for Materials Science, Japan ; University of Helsinki, Finland.
    Claesson, Per M.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry, Materials and Surfaces. KTH Royal Institute of Technology, Sweden.
    Dedinaite, Andra
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry, Materials and Surfaces. KTH Royal Institute of Technology, Sweden.
    Effect of solvent quality and chain density on normal and frictional forces between electrostatically anchored thermoresponsive diblock copolymer layers2017In: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 487, p. 88-96Article in journal (Refereed)
    Abstract [en]

    Equilibration in adsorbing polymer systems can be very slow, leading to different physical properties at a given condition depending on the pathway that was used to reach this state. Here we explore this phenomenon using a diblock copolymer consisting of a cationic anchor block and a thermoresponsive block of poly(2-isopropyl-2-oxazoline), PIPOZ. We find that at a given temperature different polymer chain densities at the silica surface are achieved depending on the previous temperature history. We explore how this affects surface and friction forces between such layers using the atomic force microscope colloidal probe technique. The surface forces are purely repulsive at temperatures <40 °C. A local force minimum at short separation develops at 40 °C and a strong attraction due to capillary condensation of a polymer-rich phase is observed close to the bulk phase separation temperature. The friction forces decrease in the cooling stage due to rehydration of the PIPOZ chain. A consequence of the adsorption hysteresis is that the friction forces measured at 25 °C are significantly lower after exposure to a temperature of 40 °C than prior to heating, which is due to higher polymer chain density on the surface after heating.

  • 4.
    Anyangwe Nwaboh, Javis
    et al.
    Physikalisch-Technische Bundesanstalt, Germany.
    Persijn, Stefan
    Research and Development VSL, Netherlands.
    Arrhenius, Karine
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Bohlen, Haleh
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Werhahn, Olav
    Physikalisch-Technische Bundesanstalt, Germany.
    Ebert, Volker
    Physikalisch-Technische Bundesanstalt, Germany.
    Metrological quantification of CO in biogas using laser absorption spectroscopy and gas chromatography2018In: Measurement science and technology, ISSN 0957-0233, E-ISSN 1361-6501Article in journal (Refereed)
    Abstract [en]

    Biogas has a vital role in the future market of renewable energy. When upgraded to biomethane, it can be injected into natural gas grids if the level of certain impurities complies with the specifications in EN16723. For some of these impurities, suitable measurement methods are lacking which hampers the quality control of biomethane to be injected into natural gas networks. Here, we report the evaluation of three detection methods suitable for carbon monoxide (CO) in biogas and biomethane applications for which EN16723 specifies an upper limit of 0.1% (1000 µmol/mol). Two of these methods are based on laser absorption spectroscopy (LAS) and one on gas chromatography (GC). Both LAS spectrometers are employing direct absorption spectroscopy and operating at 4.6µm, probing a single CO absorption line in the fundamental CO band: One – called dTDLAS (direct tunable diode laser absorption spectroscopy)- is based on a new Interband Cascade Laser specially designed for biogas and biomethane applications, while the other is based on Quantum Cascade Laser Absorption Spectroscopy (QCLAS). The GC is equipped with two packed columns (Hayesep Q and Molecular Sieve 5A) and a thermal conductivity detector. Carbon monoxide amount fraction results in biogas matrices derived using these three measurement methods are compared to amount fraction values of different, gravimetrically prepared reference gas standards of CO in biogas. These were used to validate the measurement capabilities. The measured CO amount fraction results from LAS and GC covered 10 µmol/mol to 30000 µmol/mol (system measurement ranges, LAS: 3 µmol/mol - 1000 µmol/mol, GC: 500 µmol/mol - 30000 µmol/mol) and were in excellent agreement with the gravimetric values of the gas standards. At 400 µmol/mol, the guide to the expression of uncertainty in measurement (GUM) compliant relative standard uncertainties of our calibration-free dTDLAS and the gas-calibrated QCLAS systems are estimated to be 1.4 % vs 0.5 %, respectively. The relative standard uncertainty of the GC CO measurements at 5075 µmol/mol is 1.3 %. This work demonstrates that, by means of GC and LAS, relative standard uncertainties of 1.4 % and below can be reached for CO measurements in biogas and that cost-optimized calibration-free approaches not requiring frequent use of gas standards have become available.

  • 5.
    Arrhenius, Karine
    et al.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Karlsson, Anders
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Hakonen, Aron
    Ohlson, Lars
    Fordonsgas Sverige AB, Sweden.
    Yaghooby, Haleh
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Büker, Oliver
    RISE - Research Institutes of Sweden, Safety and Transport, Measurement Science and Technology.
    Variations of fuel composition during storage at Liquefied Natural Gas refuelling stations2018In: Journal of Natural Gas Science and Engineering, ISSN 1875-5100, E-ISSN 2212-3865, Vol. 49, p. 317-323Article in journal (Refereed)
    Abstract [en]

    Liquefied Natural Gas (LNG) and Liquefied Biogas (LBG) utilization within the heavy duty transport sector is today a sustainable alternative to the use of oil. However, in spite of the high degree of insulation in the storage tank walls, it is impossible to fully avoid any net heat input from the surroundings. Due to some degree of vaporization this results in variation in gas composition during storage at refuelling stations, potentially leading to engine failures. Within this study, a vaporizer/sampler has been built and tested at a station delivering liquefied biomethane (LBG) and occasionally; such in this case, LNG to heavy and medium duty trucks. The vaporizer/sampler has then been used to study the variation of the LNG composition in the storage tank during a two weeks period. The results clearly underline a correlation between the gas phase and the liquid phase as the concentration changes follow the same trend in both phases. Two opposite effects are assumed to influence the concentration of methane, ethane and propane in the liquid and in the gas phase. On one hand, because of the probable presence of not fully mixed layers in the storage tank and due to vehicles being refuelled, both liquid and gas phases are enriched in methane at the expense of ethane and propane. On the other hand, due to boil-off effect towards the end of the storage period, both liquid and gas phases are enriched in ethane and propane at the expense of methane.

  • 6.
    Arrhenius, Karine
    et al.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Yaghooby, Haleh
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Rosell, Lars
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Büker, Oliver
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Culleton, Lucy
    National Physical Laboratory (NPL), UK.
    Bartlett, Sam
    National Physical Laboratory (NPL), UK.
    Murugan, Arul
    National Physical Laboratory (NPL), UK.
    Brewer, Paul
    National Physical Laboratory (NPL), UK.
    Li, Jianrong
    Van Swinden Laboratorium B.V. (VSL), The Netherlands.
    van der Veen, Adriaan M. H.
    Van Swinden Laboratorium B.V. (VSL), The Netherlands.
    Krom, Iris
    Van Swinden Laboratorium B.V. (VSL), The Netherlands.
    Lestremau, Francoise
    Institut national de l'environnement industriel et des risques (INERIS), France.
    Beranek, Jan
    Česky metrologicky institut (ČMI), Czech Republic.
    Suitability of vessels and adsorbents for the short-term storage of biogas/biomethane for the determination of impurities – Siloxanes, sulfur compounds, halogenated hydrocarbons, BTEX2017In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 105, p. 127-135Article in journal (Refereed)
    Abstract [en]

    Biogas is a renewable energy source with many different production pathways and various excellent opportunities to use, for example as vehicle fuel (biomethane). Reliable analytical methodologies for assessing the quality of the gas are critical to ensure that the gas can technically and safely be used. An essential part of any procedure aiming to determine the quality is the sampling and the transfer to the laboratory. One of the greatest challenges is then to ensure that the composition of the sample collected does not change between the time of sampling and the analysis. The choice of the sampling vessel to be used must be made only after fully assessing its short-term stability. In this paper, the results from short-term stability studies in different vessels (cylinders, bags and sorbents) are presented for siloxanes, BTEX, halogenated hydrocarbons and sulfur compounds. Storage of dry gas at high pressure (> 6 MPa) appears to be a good alternative however it is currently challenging to find an optimal treatment of the cylinders for all species to be assessed in biogas/biomethane. At lower pressure, adsorption effects on the inner surface of the cylinders have been observed. The use of bags and sorbent tubes also shows limitation. No existing sorbent tubes are sufficiently universal as to trap all possible impurities and high boiling compounds may adsorbed on the inner surface of the bags walls. Moreover, the presence of water when storing biogas most certainly impacts the storage stability of compounds in most vessels. Using at least two sampling methods for a given compound and comparing results will allow taking into account the eventual effects of water vapour, and adsorption on the inner surface of the vessels.

  • 7.
    Arvidsson, Martin
    et al.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Ringstad, Lovisa
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Skedung, Lisa
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Duvefelt, Kenneth
    KTH Royal Institute of Technology, Sweden.
    Rutland, Mark W.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials. KTH Royal Institute of Technology, Sweden.
    Feeling fine - the effect of topography and friction on perceived roughness and slipperiness2017In: Biotribology, ISSN 2352-5738, Vol. 11, p. 92-101Article in journal (Refereed)
    Abstract [en]

    (1) Background. To design materials with specific haptic qualities, it is important to understand both the contribution of physical attributes from the surfaces of the materials and the perceptions that are involved in the haptic interaction. (2) Methods. A series of 16 wrinkled surfaces consisting of two similar materials of different elastic modulus and 8 different wrinkle wavelengths were characterized in terms of surface roughness and tactile friction coefficient. Sixteen participants scaled the perceived Roughness and Slipperiness of the surfaces using free magnitude estimation. Friction experiments were performed both by participants and by a trained experimenter with higher control. (3) Results and discussion. The trends in friction properties were similar for the group of participants performing the friction measurements in an uncontrolled way and the experiments performed under well-defined conditions, showing that the latter type of measurements represent the general friction properties well. The results point to slipperiness as the key perception dimension for textures below 100. μm and roughness above 100. μm. Furthermore, it is apparent that roughness and slipperiness perception of these types of structures are not independent. The friction is related to contact area between finger and material. Somewhat surprising was that the material with the higher elastic modulus was perceived as more slippery. A concluding finding was that the flat (high friction) reference surfaces were scaled as rough, supporting the theory that perceived roughness itself is a multidimensional construct with both surface roughness and friction component.

  • 8.
    Badal Tejedor, Maria
    et al.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials. KTH Royal Institute of Technology, Sweden.
    Nordgren, Niklas
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Schuleit, Michael
    Novartis Pharma AG, Switzerland.
    Pazesh, Samaneh
    Uppsala University, Sweden.
    Alderborn, Göran
    Uppsala University, Sweden.
    Millqvist-Fureby, Anna
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Rutland, Mark W.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials. KTH Royal Institute of Technology, Sweden.
    Determination of interfacial amorphicity in functional powders2017In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 33, no 4, p. 920-926Article in journal (Refereed)
    Abstract [en]

    The nature of the surfaces of particles of pharmaceutical ingredients, food powders, and polymers is a determining factor for their performance in for example tableting, powder handling, or mixing. Changes on the surface structure of the material will impact the flow properties, dissolution rate, and tabletability of the powder blend. For crystalline materials, surface amorphization is a phenomenon which is known to impact performance. Since it is important to measure and control the level of amorphicity, several characterization techniques are available to determine the bulk amorphous content of a processed material. The possibility of characterizing the degree of amorphicity at the surface, for example by studying the mechanical properties of the particles' surface at the nanoscale, is currently only offered by atomic force microscopy (AFM). The AFM PeakForce QNM technique has been used to measure the variation in energy dissipation (eV) at the surface of the particles which sheds light on the mechanical changes occurring as a result of amorphization or recrystallization events. Two novel approaches for the characterization of amorphicity are presented here. First, since particles are heterogeneous, we present a methodology to present the results of extensive QNM analysis of multiple particles in a coherent and easily interpreted manner, by studying cumulative distributions of dissipation data with respect to a threshold value which can be used to distinguish the crystalline and amorphous states. To exemplify the approach, which is generally applicable to any material, reference materials of purely crystalline α-lactose monohydrate and completely amorphous spray dried lactose particles were compared to a partially amorphized α-lactose monohydrate sample. Dissipation data are compared to evaluations of the lactose samples with conventional AFM and SEM showing significant topographical differences. Finally, the recrystallization of the surface amorphous regions in response to humidity was followed by studying the dissipation response of a well-defined surface region over time, which confirms both that dissipation measurement is a useful measure of surface amorphicity and that significant recrystallization occurs at the surface in response to humidity.

  • 9.
    Bannow, J.
    et al.
    KTH Royal Institute of Technology, Sweden.
    Benjamins, J. -W
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry, Materials and Surfaces.
    Wohlert, J.
    KTH Royal Institute of Technology, Sweden.
    Löbmann, K.
    University of Copenhagen, Denmark.
    Svagan, A. J.
    KTH Royal Institute of Technology, Sweden.
    Solid nanofoams based on cellulose nanofibers and indomethacin—the effect of processing parameters and drug content on material structure2017In: International Journal of Pharmaceutics, ISSN 0378-5173, E-ISSN 1873-3476, Vol. 526, no 1-2, p. 291-299Article in journal (Refereed)
    Abstract [en]

    The unique colloidal properties of cellulose nanofibers (CNF), makes CNF a very interesting new excipient in pharmaceutical formulations, as CNF in combination with some poorly-soluble drugs can create nanofoams with closed cells. Previous nanofoams, created with the model drug indomethacin, demonstrated a prolonged release compared to films, owing to the tortuous diffusion path that the drug needs to take around the intact air-bubbles. However, the nanofoam was only obtained at a relatively low drug content of 21 wt% using fixed processing parameters. Herein, the effect of indomethacin content and processing parameters on the foaming properties was analysed. Results demonstrate that a certain amount of dissolved drug is needed to stabilize air-bubbles. At the same time, larger fractions of dissolved drug promote coarsening/collapse of the wet foam. The pendant drop/bubble profile tensiometry was used to verify the wet-foam stability at different pHs. The pH influenced the amount of solubilized drug and the processing-window was very narrow at high drug loadings. The results were compared to real foaming-experiments and solid state analysis of the final cellular solids. The parameters were assembled into a processing chart, highlighting the importance of the right combination of processing parameters (pH and time-point of pH adjustment) in order to successfully prepare cellular solid materials with up to 46 wt% drug loading.

  • 10.
    Barwick, Vicki
    et al.
    LGC Ltd, UK.
    Ellison, Stephen L. R.
    LGC Ltd, UK.
    Gjengedal, Elin
    Norwegian University of Life Sciences, Norway.
    Magnusson, Bertil
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry, Materials and Surfaces.
    Molinier, Olivier
    Aglae, France.
    Patriarca, Marina
    Istituto Superiore di Sanità, Italy.
    Sibbesen, Lorens
    LAB Quality International, Denmark.
    Vanlaethem, Nicole
    Classes Moyennes et Energie, Belgium.
    Vercruysse, Isabelle
    Belab, Belgium.
    Method validation in analytical sciences: discussions on current practice and future challenges2017In: Accreditation and Quality Assurance, ISSN 0949-1775, E-ISSN 1432-0517, Vol. 22, no 5, p. 253-263Article in journal (Refereed)
    Abstract [en]

    Eurachem held a workshop on method validation in analytical sciences in Gent, Belgium, on 9–10 May 2016. A summary of the working group discussions is provided here. The discussions covered a range of issues concerned with current practice and future challenges in method validation, i.e. setting requirements for a method to be validated; planning validation studies; validation of qualitative and semi-quantitative methods; validation of multi-parameter methods; determination of trueness/bias; assessment of working range; validation in microbiology; and method validation under flexible scope of accreditation. Delegates (129) from 24 different countries and from different backgrounds, e.g. from both public and private laboratories, laboratory associations, accreditation bodies and universities, attended the working groups, thus providing opportunities to collect a variety of views and experiences as well as to identify potential gaps in current guidance and regulations. While the practicalities of assessing method performance characteristics are generally well understood, the issue of setting requirements for those characteristics beforehand is less straightforward. Although a number of documents addressing the principles of method validation are available, guidance on dealing with more complex and ‘non-ideal’ situations, as well as examples of good practice, would be welcomed and greater harmonisation of approaches was deemed necessary. There remains a need for guidance on both the concepts that apply to ‘qualitative’ or ‘nominal’ test methods and on the practical implementation of validation studies in such cases.

  • 11.
    Bender, P.
    et al.
    University of Cantabria, Spain .
    Bogart, L. K.
    University College London, UK .
    Posth, O.
    Physikalisch-Technische Bundesanstalt, Germany .
    Szczerba, W.
    Bundesanstalt für Materialforschung Und-prüfung (BAM), Germany ; AGH University of Science and Technology, Poland .
    Rogers, S. E.
    ISIS-STFC Neutron Scattering Facility, UK.
    Castro, A.
    SOLVE Research and Consultancy AB, Sweden .
    Nilsson, L.
    SOLVE Research and Consultancy AB, Sweden ; Lund University, Sweden .
    Zeng, L. J.
    Chalmers University of Technology, Sweden .
    Sugunan, Abhilash
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Sommertune, Jens
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Fornara, A.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    González-Alonso, D.
    University of Cantabria, Spain .
    Fernández Barquín, L.
    University of Cantabria, Spain .
    Johansson, Christer
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Structural and magnetic properties of multi-core nanoparticles analysed using a generalised numerical inversion method2017In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 7, article id 45990Article in journal (Refereed)
    Abstract [en]

    The structural and magnetic properties of magnetic multi-core particles were determined by numerical inversion of small angle scattering and isothermal magnetisation data. The investigated particles consist of iron oxide nanoparticle cores (9 nm) embedded in poly(styrene) spheres (160 nm). A thorough physical characterisation of the particles included transmission electron microscopy, X-ray diffraction and asymmetrical flow field-flow fractionation. Their structure was ultimately disclosed by an indirect Fourier transform of static light scattering, small angle X-ray scattering and small angle neutron scattering data of the colloidal dispersion. The extracted pair distance distribution functions clearly indicated that the cores were mostly accumulated in the outer surface layers of the poly(styrene) spheres. To investigate the magnetic properties, the isothermal magnetisation curves of the multi-core particles (immobilised and dispersed in water) were analysed. The study stands out by applying the same numerical approach to extract the apparent moment distributions of the particles as for the indirect Fourier transform. It could be shown that the main peak of the apparent moment distributions correlated to the expected intrinsic moment distribution of the cores. Additional peaks were observed which signaled deviations of the isothermal magnetisation behavior from the non-interacting case, indicating weak dipolar interactions.

  • 12.
    Besharat, Zahra
    et al.
    KTH Royal Institute of Technology, Sweden.
    Yazdi, Milad Ghadami
    KTH Royal Institute of Technology, Sweden.
    Wakeham, Deborah
    KTH Royal Institute of Technology, Sweden.
    Johnson, Magnus
    KTH Royal Institute of Technology, Sweden.
    Rutland, Mark W.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials. KTH Royal Institute of Technology, Sweden.
    Gothelid, Mats
    KTH Royal Institute of Technology, Sweden.
    Gronbeck, Henrik
    Chalmers University of Technology, Sweden.
    Se-C Cleavage of Hexane Selenol at Steps on Au(111)2018In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 34, no 8, p. 2630-2636Article in journal (Refereed)
    Abstract [en]

    Selenols are considered as an alternative to thiols in self-assembled monolayers, but the Se-C bond is one limiting factor for their usefulness. In this study, we address the stability of the Se-C bond by a combined experimental and theoretical investigation of gas phase-deposited hexane selenol (CH3(CH2)(5)SeH) on Au(111) using photoelectron spectroscopy, scanning tunneling microscopy, and density functional theory (DFT). Experimentally, we find that initial adsorption leaves atomic Se on the surface without any carbon left on the surface, whereas further adsorption generates a saturated selenolate layer. The Se 3d component from atomic Se appears at 0.85 eV lower binding energy than the selenolate-related component. DFT calculations show that the most stable structure of selenols on Au(111) is in the form of RSe-Au-SeR complexes adsorbed on the unreconstructed Au(111) surface. This is similar to thiols on Au(111). Calculated Se 3d core-level shifts between elemental Se and selenolate in this structure nicely reproduce the experimentally recorded shifts. Dissociation of RSeH and subsequent formation of RH are found to proceed with high barriers on defect-free Au(111) terraces, with the highest barrier for scissoring R-Se. However, at steps, these barriers are considerably lower, allowing for Se-C bond breaking and hexane desorption, leaving elemental Se at the surface. Hexane is the selenol to selenolate formed by replacing the Se-C bond with a H-C bond by using the hydrogen liberated from transformation.

  • 13.
    Bhattacharya, Kunal
    et al.
    Karolinska Institutet, Sweden.
    Sacchetti, Cristiano
    La Jolla Institute for Allergy and Immunology, USA; University of California San Diego, USA.
    Costa, Pedro M.
    Karolinska Institutet, Sweden.
    Sommertune, Jens
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Brandner, Birgit D.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Magrini, Andrea
    University of Rome Tor Vergata, Italy.
    Rosato, Nicola
    University of Rome Tor Vergata, Italy.
    Bottini, Nunzio
    La Jolla Institute for Allergy and Immunology, USA; University of California San Diego, USA.
    Bottini, Massimo
    University of Rome Tor Vergata, Italy; Sanford Burnham Presbys Medical Discovery Institute, USA.
    Fadeel, Bengt
    Karolinska Institutet, Sweden.
    Nitric Oxide Dependent Degradation of Polyethylene Glycol-Modified Single-Walled Carbon Nanotubes: Implications for Intra-Articular Delivery2018In: Advanced Healthcare Materials, ISSN 2192-2640, E-ISSN 2192-2659, Vol. 7, no 6, article id 1700916Article in journal (Refereed)
    Abstract [en]

    Polyethylene glycol (PEG)-modified carbon nanotubes have been successfully employed for intra-articular delivery in mice without systemic or local toxicity. However, the fate of the delivery system itself remains to be understood. In this study 2 kDa PEG-modified single-walled carbon nanotubes (PNTs) are synthesized, and trafficking and degradation following intra-articular injection into the knee-joint of healthy mice are studied. Using confocal Raman microspectroscopy, PNTs can be imaged in the knee-joint and are found to either egress from the synovial cavity or undergo biodegradation over a period of 3 weeks. Raman analysis discloses that PNTs are oxidatively degraded mainly in the chondrocyte-rich cartilage and meniscus regions while PNTs can also be detected in the synovial membrane regions, where macrophages can be found. Furthermore, using murine chondrocyte (ATDC-5) and macrophage (RAW264.7) cell lines, biodegradation of PNTs in activated, nitric oxide (NO)-producing chondrocytes, which is blocked upon pharmacological inhibition of inducible nitric oxide synthase (iNOS), can be shown. Biodegradation of PNTs in macrophages is also noted, but after a longer period of incubation. Finally, cell-free degradation of PNTs upon incubation with the peroxynitrite-generating compound, SIN-1 is demonstrated. The present study paves the way for the use of PNTs as delivery systems in the treatment of diseases of the joint.

  • 14.
    Boge, Lucas
    et al.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry, Materials and Surfaces.
    Umerska, Anita
    INSERM U 1066, France ; Université Angers, France.
    Matougui, Nada
    INSERM U 1066, France ; Université Angers,France.
    Bysell, Helena
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry, Materials and Surfaces.
    Ringstad, Lovisa
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry, Materials and Surfaces.
    Davoudi, Mina
    Lund University, Sweden.
    Eriksson, Jonny
    Uppsala University, Sweden.
    Edwards, Katarina
    Uppsala University, Sweden.
    Andersson, Martin
    Chalmers University of Technology, Sweden.
    Cubosomes post-loaded with antimicrobial peptides: Characterization, bactericidal effect and proteolytic stability2017In: International Journal of Pharmaceutics, ISSN 0378-5173, E-ISSN 1873-3476, Vol. 526, no 1-2, p. 400-412Article in journal (Refereed)
    Abstract [en]

    Novel antibiotics, such as antimicrobial peptides (AMPs), have recently attended more and more attraction. In this work, dispersed cubic liquid crystalline gel (cubosomes) was used as drug delivery vehicles for three AMPs (AP114, DPK-060 and LL-37). Association of peptides onto cubosomes was studied at two cubosome/peptide ratios using high performance liquid chromatography, ζ-potential and circular dichroism measurements. AMPs impact on the cubosome structure was investigated using small angle x-ray scattering and cryogenic transmission electron microscopy. The antimicrobial effect of the AMP loaded cubosomes was studied in vitro by minimum inhibitory concentration and time-kill assays. Proteolytic protection was investigated by incubating the formulations with two elastases and the antimicrobial effect after proteolysis was studied using radial diffusion assay. Different association efficacy onto the cubosomes was observed among the AMPs, with LL-37 showing greatest association (>60%). AP114 loaded cubosomes displayed a preserved antimicrobial effect, whereas for LL-37 the broad spectrum bacterial killing was reduced to only comprise Gram-negative bacteria. Interestingly, DPK-060 loaded cubosomes showed a slight enhanced effect against S. aureus and E. coli strains. Moreover, the cubosomes were found to protect LL-37 from proteolytic degradation, resulting in a significantly better bactericidal effect after being subjected to elastase, compared to unformulated peptide.

  • 15.
    Boge, Lukas
    et al.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation. Chalmers University of Technology, Sweden.
    Hallstensson, Karin
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Ringstad, Lovisa
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Johansson, Jenny
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Andersson, Therese
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Davoudi, Mina
    Lund University, Sweden.
    Larsson, Per Tomas
    RISE - Research Institutes of Sweden, Bioeconomy.
    Mahlapuu, Margit
    Promore Pharma AB, Sweden; University of Gothenburg, Sweden.
    Håkansson, Joakim
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Andersson, Martin
    Chalmers University of Technology, Sweden.
    Cubosomes for topical delivery of the antimicrobial peptide LL-372018In: European journal of pharmaceutics and biopharmaceutics, ISSN 0939-6411, E-ISSN 1873-3441, Vol. 134, p. 60-67, article id S0939-6411(18)31196-2Article in journal (Refereed)
    Abstract [en]

    In this study, the use of cubosomes for topical delivery of the antimicrobial peptide (AMP) LL-37 was investigated. Topical delivery of AMPs is of great interest for treatment of skin infections caused by bacteria, such as Staphylococcus aureus. AMP containing cubosomes were produced by three different preparation protocols and compared: i) pre-loading, where LL-37 was incorporated into a liquid crystalline gel, which thereafter was dispersed into nanoparticles, ii) post-loading, where LL-37 was let to adsorb onto pre-formed cubosomes, and iii) hydrotrope-loading, where LL-37 was incorporated during the spontaneously formed cubosomes in an ethanol/glycerol monooleate mixture. Particle size and size distribution were analyzed using dynamic light scattering (DLS), liquid crystalline structure by small angle x-ray scattering (SAXS) and release of LL-37 by a fluorescamine assay. Proteolytic protection of LL-37 as well as bactericidal effect after enzyme exposure was investigated. The skin irritation potential of cubosomes was examined by an in vitro epidermis model. Finally, the bacterial killing property of the cubosomes was examined by an ex vivo pig skin wound infection model with Staphylococcus aureus. Data showed that a high loading of LL-37 induced formation of vesicles in case of cubosomes prepared by sonication (pre-loading). No release of LL-37 was observed from the cubosomes, indicating strong association of the peptide to the particles. Proteolysis studies showed that LL-37 was fully protected against enzymatic attacks while associated with the cubosomes, also denoting strong association of the peptide to the particles. As a consequence, bactericidal effect after enzyme exposure remained, compared to pure LL-37 which was subjected to proteolysis. No skin irritation potential of the cubosomes was found, thus enabling for topical administration. The ex vivo wound infection model showed that LL-37 in pre-loaded cubosomes killed bacteria most efficient.

  • 16.
    Chen, Chengdong
    et al.
    Xiamen University, China ; KTH Royal Institute of Technology, Sweden.
    Hou, Ruiqing
    Xiamen University, China ; Institute of Materials Research, Germany.
    Zhang, Fan
    KTH Royal Institute of Technology, Sweden.
    Dong, Shigang
    Xiamen University, China.
    Claesson, Per Martin
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry, Materials and Surfaces. Xiamen University, China.
    Lin, Changjian
    KTH Royal Institute of Technology, Sweden.
    Pan, Jinshan
    KTH Royal Institute of Technology, Sweden.
    Heating-Induced Enhancement of Corrosion Protection of Carbon Steel by a Nanocomposite Film Containing Mussel Adhesive Protein2017In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 164, no 4, p. C188-C193Article in journal (Refereed)
    Abstract [en]

    Application of protective coatings on metals may involve a thermal treatment process. In this study, the effect of thermal treatment up to 200?C on the corrosion protection was investigated for nanocomposite films composed of mussel adhesive protein (MAP), CeO2 nanoparticles and Na2HPO4 deposited on carbon steel. The morphology and microstructure of the pre-formed nanocomposite film were characterized by scanning electron microscopy/energy dispersive spectroscopy and atomic force microscopy (AFM). The changes in the chemical structure of the nanocomposite film due to the thermal treatment were investigated by infrared reflection absorption spectroscopy. The corrosion protection of the unheated and heated nanocomposite films on carbon steel was evaluated by electrochemical impedance spectroscopy and details of the corrosion process were elucidated by in-situ AFM measurements in 0.1 M NaCl solution. The results show a certain increase in the corrosion protection with time of the nanocomposite film for carbon steel. The analyses reveal that thermal treatment leads to a reduction of water molecules in the nanocomposite film, and an enhanced cross-linking and cohesion of the film due to oxidation of catechols to o-quinones. As a result, the film becomes more compact and gives improved corrosion protection for carbon steel.

  • 17.
    Chinga-Carrasco, Gary
    et al.
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Ehman, Nanci V.
    Instituto de Materiales de Misiones (IMAM), Misiones Argentina.
    Pettersson, Jennifer
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Vallejos, Maria E.
    Instituto de Materiales de Misiones (IMAM), Misiones Argentina.
    Brodin, Malin
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Felissia, Fernando E.
    Instituto de Materiales de Misiones (IMAM), Misiones Argentina.
    Håkansson, Joakim
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Area, Maria C.
    Instituto de Materiales de Misiones (IMAM), Misiones Argentina.
    Pulping and Pretreatment Affect the Characteristics of Bagasse Inks for Three-dimensional Printing2018In: ACS Sustainable Chemistry and Engineering, ISSN 2168-0485, Vol. 6, no 3, p. 4068-4075Article in journal (Refereed)
    Abstract [en]

    Bagasse is an underutilized agro-industrial residue with great potential as raw material for the production of cellulose nanofibrils (CNF) for a range of applications. In this study, we have assessed the suitability of bagasse for production of CNF for three-dimensional (3D) printing. First, pulp fibers were obtained from the bagasse raw material using two fractionation methods, i.e. soda and hydrothermal treatment combined with soda. Second, the pulp fibers were pretreated by TEMPO-mediated oxidation using two levels of oxidation for comparison purposes. Finally, the CNF were characterized in detail and assessed as inks for 3D printing. The results show that CNF produced from fibers obtained by hydrothermal and soda pulping were less nanofibrillated than the corresponding material produced by soda pulping. However, the CNF sample obtained from soda pulp was cytotoxic, apparently due to a larger content of silica particles. All the CNF materials were 3D printable. We conclude that the noncytotoxic CNF produced from hydrothermally and soda treated pulp can potentially be used as inks for 3D printing of biomedical devices. 

  • 18.
    De Jong, Wim H.
    et al.
    National Institute for Public Health and the Environment (RIVM), The Netherlands.
    Hoffmann, Sebastian
    Seh consulting + services, Germany.
    Lee, Michelle
    Nelson Laboratories, Inc., USA.
    Kandárová, Helena
    MatVitro Life Science Laboratories, Slovakia.
    Pellevoisin, Christian
    EPISKIN, France.
    Haishima, Yuji
    National Institute of Health Sciences (NIHS), Japan.
    Rollins, Beau
    Arthrex Inc., USA.
    Zdawczyk, Austin
    NAMSA, USA.
    Willoughby, Jamin
    Cyprotex US LCC, USA.
    Bachelor, Michael
    MatTek Corporation, USA.
    Schatz, Timothy
    American Preclinical Services LLC, USA.
    Skoog, Shelby
    US Food and Drug Administration, Center for Devices and Radiological Health, USA.
    Parker, Sherry
    WuXi AppTec, USA.
    Sawyer, Anita
    Becton Dickinson, USA.
    Pescio, Paolo
    Eurofins Biolab Srl, Italy.
    Fant, Kristina
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Kim, Kwang-Mahn
    Yonsei University, South Korea.
    Kwon, Jae Sung
    Yonsei University, South Korea.
    Gehrke, Helge
    Eurofins Biopharma, Germany.
    Hofman-Hüther, Hana
    Eurofins Biopharma, Germany.
    Meloni, Morisa
    VitroScreen, Italy.
    Julius, Conrad
    Envigo CRS GmbH, Germany.
    Briotet, Damien
    NAMSA, France.
    Letasiova, Silvia
    MatTek In Vitro Life Science Laboratories, Slovakia.
    Kato, Reiko
    National Institute of Health Sciences (NIHS), Japan.
    Miyajima, Atsuko
    National Institute of Health Sciences (NIHS), Japan.
    De La Fonteyne, Liset J. J.
    National Institute for Public Health and the Environment (RIVM), The Netherlands.
    Videau, Christelle
    EPISKIN, France.
    Tornier, Carine
    EPISKIN, France.
    Turley, Audrey P.
    Nelson Laboratories, Inc., USA.
    Christiano, Nicholas
    Arthrex, Inc., USA.
    Rollins, Thor S.
    Nelson Laboratories, Inc., USA.
    Coleman, Kelly P.
    Medtronic, plc, USA.
    Round robin study to evaluate the reconstructed human epidermis (RhE) model as an in vitro skin irritation test for detection of irritant activity in medical device extracts2018In: Toxicology in Vitro, ISSN 0887-2333, E-ISSN 1879-3177Article in journal (Refereed)
    Abstract [en]

    Assessment of skin irritation is an essential component of the safety evaluation of medical devices. OECD Test Guideline 439 describes the use of reconstructed human epidermis (RhE) as an in vitro test system for classification of skin irritation by neat chemicals. An international round robin study was conducted to evaluate the RhE method for determination of skin irritant potential of medical device extracts. Four irritant polymers and three non-irritant controls were obtained or developed that had demonstrated their suitability to act as positive or negative test samples. The RhE tissues (EpiDerm™ and SkinEthic™ RHE) were dosed with 100 μL aliquots of either saline or sesame oil extract. Incubation times were 18 h (EpiDerm™) and 24 h (SkinEthic™ RHE). Cell viability reduction > 50% was indicative of skin irritation. Both the EpiDerm™ and SkinEthic™ RHE tissues were able to correctly identify virtually all of the irritant polymer samples either in the saline, sesame oil or both solvent extracts. Our results indicate that RhE tissue models can detect the presence of strong skin irritants at low levels in dilute medical device polymer extracts. Therefore, these models may be suitable replacements for the rabbit skin irritation test to support the biological evaluation of medical devices.

  • 19.
    Drake, Henrik
    et al.
    Linnæus University, Sweden.
    Ivarsson, Magnus
    Swedish Museum of Natural History, Sweden.
    Bengtson, Stefan
    Swedish Museum of Natural History, Sweden.
    Heim, Christine
    Georg-August University, Germany.
    Siljeström, Sandra
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Whitehouse, Martin J.
    Swedish Museum of Natural History, Sweden.
    Broman, Curt
    Stockholm University, Sweden.
    Belivanova, Veneta
    Swedish Museum of Natural History, Sweden.
    Åström, Mats E.
    Linnæus University, Sweden.
    Anaerobic consortia of fungi and sulfate reducing bacteria in deep granite fractures2017In: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 8, no 1, article id 55Article in journal (Refereed)
    Abstract [en]

    The deep biosphere is one of the least understood ecosystems on Earth. Although most microbiological studies in this system have focused on prokaryotes and neglected microeukaryotes, recent discoveries have revealed existence of fossil and active fungi in marine sediments and sub-seafloor basalts, with proposed importance for the subsurface energy cycle. However, studies of fungi in deep continental crystalline rocks are surprisingly few. Consequently, the characteristics and processes of fungi and fungus-prokaryote interactions in this vast environment remain enigmatic. Here we report the first findings of partly organically preserved and partly mineralized fungi at great depth in fractured crystalline rock (-740 m). Based on environmental parameters and mineralogy the fungi are interpreted as anaerobic. Synchrotron-based techniques and stable isotope microanalysis confirm a coupling between the fungi and sulfate reducing bacteria. The cryptoendolithic fungi have significantly weathered neighboring zeolite crystals and thus have implications for storage of toxic wastes using zeolite barriers. © 2017 The Author(s).

  • 20.
    Ekendahl, Susanne
    et al.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Bark, Mathias
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Engelbrektsson, Johan
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Karlsson, Carl-Anton
    Nordic Paper Bäckhammars Bruk AB, Sweden.
    Niyitegeka, Domitille
    Nordic Paper Bäckhammars Bruk AB, Sweden.
    Strömberg, Niklas
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Energy-efficient outdoor cultivation of oleaginous microalgae at northern latitudes using waste heat and flue gas from a pulp and paper mill2018In: Algal Research, ISSN 2211-9264, Vol. 31, p. 138-146Article in journal (Refereed)
    Abstract [en]

    Energy efficient cultivation is the major bottleneck for microalgal biomass production on a large scale and considered very difficult to attain at northern latitudes. In this study an unconventional method for industrial microalgae cultivation for bio-oil production using pulp and paper mill waste resources while harvesting only once a year was performed, mainly in order to investigate the energy efficiency of the process. Algae were cultivated for three months in 2014 in covered pond systems with access to flue gas and waste heat from the industry, and the biomass was recovered as thick sediment sludge after dewatering. The cultivation systems, designed to manage the waste resources, reached a promising photosynthetic efficiency of at most 1.1%, a net energy ratio (NER) of 0.25, and a projected year-round energy biomass yield per area 5.2 times higher than corresponding rapeseed production at the location. Thus, microalgae cultivation was, for the first time, proven energy efficient in a cold continental climate. Energy-rich indigenous communities quickly out-competed the oleaginous monocultures used for inoculation. The recovered biomass had higher heating values of 20–23 MJ kg− 1 and contained 14–19% oil dominated by C16 followed by C18 fatty acids. The cultivation season at 59°15′N, 14°18′E was projected to be efficient for 10 months and waste heat drying of the biomass is suggested for two winter months. The technique is proposed for carbon sequestering and energy storage in the form of microalgal sludge or dry matter for later conversion into biochemicals.

  • 21.
    Farajzadeh Khosroshahi, S.
    et al.
    University of Padova, Italy.
    Olsson, Robin
    RISE - Research Institutes of Sweden, Swerea, Swerea SICOMP.
    Wysocki, Maciej
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Zaccariotto, M.
    University of Padova, Italy.
    Galvanetto, U.
    University of Padova, Italy.
    Response of a helmet liner under biaxial loading2018In: Polymer testing, ISSN 0142-9418, E-ISSN 1873-2348, Vol. 72, p. 110-114Article in journal (Refereed)
    Abstract [en]

    Helmets are the most effective protective item for motorcyclists. The liner of the helmet is the part of the helmet which dissipates most of the impact energy and mitigates the risk of head injuries. It has been proposed that the helmet test standards should include assessment of the helmets for oblique impacts that is not currently addressed in the standards. A conventional uniaxial compression test method is still used for characterization of the helmet liner material. However, compressive tests of EPS foams provide reliable results for normal loading on EPS, but do not provide a realistic result for oblique impacts. Therefore, we carried out experimental tests to measure the response of EPS foams, which are commonly used for helmet liners, under biaxial loading. The result of our experiments show that the shear response of EPS foams is a function of axial compression, and increasing the axial strain leads to increased shear stiffness, and thus higher levels of shear stress. We also showed that including shear-stiffening of EPS in the FE assessment of helmets may change the headform rotational acceleration by 25%. Therefore, such behavior of EPS foams should be included in FE analysis of helmets in the case of oblique impacts for a more realistic assessment of their performance.

  • 22.
    Ferraris, M.
    et al.
    Politecnico di Torino, Italy.
    Perero, S.
    Politecnico di Torino, Italy.
    Ferraris, S.
    Politecnico di Torino, Italy.
    Miola, M.
    Politecnico di Torino, Italy.
    Vernè, E.
    Politecnico di Torino, Italy.
    Skoglund, S.
    KTH Royal Institute of Technology, Sweden.
    Blomberg, Eva
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry, Materials and Surfaces. KTH Royal Institute of Technology, Sweden.
    Odnevall Wallinder, I.
    KTH Royal Institute of Technology, Sweden.
    Antibacterial silver nanocluster/silica composite coatings on stainless steel2017In: Applied Surface Science, ISSN 0169-4332, E-ISSN 1873-5584, Vol. 396, p. 1546-1555Article in journal (Refereed)
    Abstract [en]

    A coating made of silver nanocluster/silica composites has been deposited, via a radio frequency (RF) co-sputtering technique, for the first time onto stainless steel (AISI 304L) with the aim to improve its antibacterial properties. Different thermal treatments after coating deposition have been applied in order to optimize the coating adhesion, cohesion and its antibacterial properties. Its applicability has been investigated at realistic conditions in a cheese production plant. The physico-chemical characteristics of the coatings have been analyzed by means of different bulk and surface analytical techniques. Field emission scanning electron microscopy (FESEM), X-ray Photoelectron Spectroscopy (XPS), contact angle measurements and atomic force microscopy (AFM) were employed to assess coating morphology, composition, surface roughness, wetting properties, size and local distribution of the nanoparticles within the coating. Tape tests were used to determine the adhesion/cohesion properties of the coating. The amount and time-dependence of released silver in solutions of acetic acid, artificial water, artificial tap water and artificial milk were determined by means of Atomic Absorption Spectroscopy (AAS). The antibacterial effect of the coating was evaluated at different experimental conditions using a standard bacterial strain of Staphylococcus aureus in compliance with National Committee for Clinical Laboratory Standards (NCCLS) and AATCC 147 standards. The Ahearn test was performed to measure the adhesion of bacteria to the coated stainless steel surface compared with a control surface. The antibacterial coating retained its antibacterial activity after thermal treatment up to 450 °C and after soaking in common cleaning products for stainless steel surfaces used for e.g. food applications. The antibacterial capacity of the coating remained at high levels for 1-5 days, and showed a good capacity to reduce the adhesion of bacteria up to 30 days. Only a few percent of silver in the coating was released into acetic acid, even after 10 days of exposure at 40 °C. Most silver (> 90%) remained also in the coating even after 240 h of continuous exposure. Similar observations were made after repeated exposure at 100 °C. Very low levels of released silver in solution were observed in artificial milk. No release of silver nanoparticles was observed either in synthetic tap water or in artificial milk at given conditions. The coating further displayed good antibacterial properties also when tested during working conditions in a cheese production plant.

  • 23.
    Ferreira, Ana R. V.
    et al.
    Universidade NOVA de Lisboa, Portugal.
    Haapanen, Janne
    Tampere University of Technology, Finland.
    Mäkelä, Jyrki M.
    Tampere University of Technology, Finland.
    Bratvold, Jon E.
    University of Oslo, Norway.
    Nilsen, Ola
    University of Oslo, Norway.
    Tuominen, Mikko
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry, Materials and Surfaces.
    Alves, Vitor D.
    Universidade de Lisboa, Portugal.
    Coelhoso, Isabel M.
    Universidade NOVA de Lisboa, Portugal.
    Comparison of different coating techniques on the properties of FucoPol films2017In: International Journal of Biological Macromolecules, ISSN 0141-8130, E-ISSN 1879-0003, Vol. 103, p. 268-274Article in journal (Refereed)
    Abstract [en]

    Plasma deposition, liquid flame spray (LFS) and atomic layer deposition (ALD) were used to form inorganic coatings in new exopolysaccharide (FucoPol) biodegradable films. Coated films were characterised in terms of surface, optical and barrier properties in order to evaluate their potential use in food packaging. FucoPol films presented dense and homogeneous surface with instant water contact angle of 95̊. Plasma deposition of perfluorohexane (PFH) on FucoPol surface has not shown significant improvement in the hydrophobic behaviour over the time. The FucoPol coating of SiO2 nanoparticles deposited by LFS and plasma deposition of PFH have shown higher instant water contact angle (135°) caused by coating surface roughness, but this hydrophobic behaviour was not stable over time. FucoPol films coated only with TiO2 deposited by ALD and combination of that with plasma deposition of PFH have shown stable water contact angle during time (90̊ and 115̊, respectively), transparency in the same order of magnitude and significantly lower permeability to water vapour (3.45 × 10−11 mol/m s Pa and 3.45 × 10−11 mol/m s Pa when compared to uncoated films with 5.32 × 10−11 mol/m s Pa). Moreover, films coated with TiO2-PFH have also shown a permeability to oxygen of 1.70 × 10−16 molm/m2s Pa which is 67% lower than uncoated films.

  • 24.
    Flys, Olena
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport, Measurement Science and Technology. Halmstad University, Sweden.
    Jarlemark, Per
    RISE - Research Institutes of Sweden, Safety and Transport, Measurement Science and Technology.
    Petronis, Sarunas
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Stenlund, Patrik
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Rosen, B. -G
    Halmstad University, Sweden.
    Applicability of characterization techniques on fine scale surfaces2018In: Surface Topography: Metrology and Properties, ISSN 2051-672X, Vol. 6, no 3, article id 034015Article in journal (Refereed)
    Abstract [en]

    In this study, several surface topographies typical for dental implants were evaluated by different measurement techniques. The samples were prepared by machine turning, wet chemical etching and electrochemical polishing of titanium discs. The measurement techniques included an atomic force microscope (AFM), coherence scanning interferometer (CSI) and a 3D stereo scanning electron microscope (SEM). The aim was to demonstrate and discuss similarities and differences in the results provided by these techniques when analyzing submicron surface topographies. The estimated surface roughness parameters were not directly comparable since the techniques had different surface spatial wavelength band limits. However, the comparison was made possible by applying a 2D power spectral density (PSD) function. Furthermore, to simplify the comparison, all measurements were characterized using the ISO 25178 standard parameters. Additionally, a Fourier transform was applied to calculate the instrument transfer function in order to investigate the behavior of CSI at different wavelength ranges. The study showed that 3D stereo SEM results agreed well with AFM measurements for the studied surfaces. Analyzed surface parameter values were in general higher when measured by CSI in comparison to both AFM and 3D stereo SEM results. In addition, the PSD analysis showed a higher power spectrum density in the lower frequency range 10-2-10-1 μm-1 for the CSI compared with the other techniques.

  • 25.
    Fornaro, Teresa
    et al.
    Geophysical Laboratory of the Carnegie Institution for Science, US ; NAF-Astrophysical Observatory of Arcetri, Italy.
    Boosman, Arjen
    Utrecht University, The Netherlands.
    Brucato, John R.
    NAF-Astrophysical Observatory of Arcetri, Italy.
    ten Kate, Inge Loes
    Utrecht University, The Netherlands.
    Siljeström, Sandra
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Poggiali, Giovanni
    NAF-Astrophysical Observatory of Arcetri, Italy ; Università degli Studi di Firenze, Italy.
    Steele, Andrew
    Geophysical Laboratory of the Carnegie Institution for Science, US.
    Hazen, Robert M.
    Geophysical Laboratory of the Carnegie Institution for Science, US.
    UV irradiation of biomarkers adsorbed on minerals under Martian-like conditions: Hints for life detection on Mars2018In: Icarus (New York, N.Y. 1962), ISSN 0019-1035, E-ISSN 1090-2643, Vol. 313, p. 38-60Article in journal (Refereed)
    Abstract [en]

    Laboratory simulations of Martian conditions are essential to develop quantitative models for the survival of organic biomarkers for future Mars exploration missions. In this work, we report the results of ultraviolet (UV) irradiation processing of biomarkers adsorbed on minerals under Martian-like conditions. Specifically, we prepared Mars soil analogues by doping forsterite, lizardite, antigorite, labradorite, natrolite, apatite and hematite minerals with organic compounds considered as potential biomarkers of extant terrestrial life such as the nucleotides adenosine monophosphate (AMP) and uridine monophosphate (UMP). We characterized such Mars soil analogues by means of Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS), Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) and Confocal Raman Imaging Spectroscopy (CRIS), in order to get insights into the specific molecule-mineral interactions and explore the capabilities of different techniques to reveal diagnostic features of these biomarkers. Then, we performed irradiation experiments in the mid-UV spectral region under simulated Martian conditions and under terrestrial ambient conditions for comparison, monitoring the degradation process through DRIFTS. We observed that degradation under Martian-like conditions occurs much slower than in terrestrial ambient conditions. The minerals labradorite and natrolite mainly promote photodegradation of nucleotides, hematite and forsterite exhibit an intermediate degrading effect, while apatite, lizardite and antigorite do not show any significant catalytic effect on the degradation of the target organic species.

  • 26.
    Fornaro, Teresa
    et al.
    Geophysical Laboratory of the Carnegie Institution for Science, US ; INAF-Astrophysical Observatory of Arcetri, Italy.
    Boosman, Arjen
    Utrecht University, Netherlands.
    Brucato, John R.
    INAF-Astrophysical Observatory of Arcetri, Italy.
    ten Kate, Inge Loes
    Utrecht University, Netherlands.
    Siljeström, Sandra
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Poggiali, Giovanni
    INAF-Astrophysical Observatory of Arcetri, Italy ; Università degli Studi di Firenze, Italy.
    Steele, Andrew
    Geophysical Laboratory of the Carnegie Institution for Science, US.
    Hazen, Robert M.
    Geophysical Laboratory of the Carnegie Institution for Science, US.
    UV irradiation of biomarkers adsorbed on minerals under Martian-like conditions: Hints for life detection on Mars2018In: Icarus (New York, N.Y. 1962), ISSN 0019-1035, E-ISSN 1090-2643, Vol. 313, p. 38-60Article in journal (Refereed)
    Abstract [en]

    Laboratory simulations of Martian conditions are essential to develop quantitative models for the survival of organic biomarkers for future Mars exploration missions. In this work, we report the results of ultraviolet (UV) irradiation processing of biomarkers adsorbed on minerals under Martian-like conditions. Specifically, we prepared Mars soil analogues by doping forsterite, lizardite, antigorite, labradorite, natrolite, apatite and hematite minerals with organic compounds considered as potential biomarkers of extant terrestrial life such as the nucleotides adenosine monophosphate (AMP) and uridine monophosphate (UMP). We characterized such Mars soil analogues by means of Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS), Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) and Confocal Raman Imaging Spectroscopy (CRIS), in order to get insights into the specific molecule-mineral interactions and explore the capabilities of different techniques to reveal diagnostic features of these biomarkers. Then, we performed irradiation experiments in the mid-UV spectral region under simulated Martian conditions and under terrestrial ambient conditions for comparison, monitoring the degradation process through DRIFTS. We observed that degradation under Martian-like conditions occurs much slower than in terrestrial ambient conditions. The minerals labradorite and natrolite mainly promote photodegradation of nucleotides, hematite and forsterite exhibit an intermediate degrading effect, while apatite, lizardite and antigorite do not show any significant catalytic effect on the degradation of the target organic species.

  • 27.
    Fromell, Karin
    et al.
    Uppsala University, Sweden.
    Yang, Yi
    Goteborg University, Sweden.
    Nilsson Ekdahl, Kristina
    Linnaeus University, Sweden.
    Nilsson, Bo
    Linnaeus University, Sweden.
    Berglin, Mattias
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Elwing, Hans
    Goteborg University, Sweden.
    Absence of conformational change in complement factor 3 and factor XII adsorbed to acrylate polymers is related to a high degree of polymer backbone flexibility2017In: Biointerphases, ISSN 1934-8630, E-ISSN 1559-4106, Vol. 12, no 2, article id 02D417Article in journal (Refereed)
    Abstract [en]

    In previous investigations, the authors have examined the adsorption of albumin, immunoglobulin, and fibrinogen to a series of acrylate polymers with different backbone and side-group flexibility. The authors showed that protein adsorption to acrylates with high flexibility, such as poly(lauryl methacrylate) (PLMA), tends to preserve native conformation. In the present study, the authors have continued this work by examining the conformational changes that occur during the binding of complement factor 3 (C3) and coagulation factor XII (FXII). Native C3 adsorbed readily to all solid surfaces tested, including a series of acrylate surfaces of varying backbone flexibility. However, a monoclonal antibody recognizing a "hidden" epitope of C3 (only exposed during C3 activation or denaturation) bound to the C3 on the rigid acrylate surfaces or on polystyrene (also rigid), but not to C3 on the flexible PLMA, indicating that varying degrees of conformational change had occurred with binding to different surfaces. Similarly, FXII was activated only on the rigid poly(butyl methacrylate) surface, as assessed by the formation of FXIIa-antithrombin (AT) complexes; in contrast, it remained in its native form on the flexible PLMA surface. The authors also found that water wettability hysteresis, defined as the difference between the advancing and receding contact angles, was highest for the PLMA surface, indicating that a dynamic change in the interface polymer structure may help protect the adsorbed protein from conformational changes and denaturation.

  • 28.
    Földváry, Veronika
    et al.
    Slovak University of Technology, Slovakia.
    Bekö, Gabriel
    Technical University of Denmark, Denmark.
    Langer, Sarka
    IVL Swedish Environmental Research Institute, Sweden ; Chalmers University of Technology, Sweden.
    Arrhenius, Karine
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Petráš, Dusan
    Slovak University of Technology, Slovakia.
    Effect of energy renovation on indoor air quality in multifamily residential buildings in Slovakia2017In: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 122, p. 363-372Article in journal (Refereed)
    Abstract [en]

    Buildings are responsible for a substantial portion of the global energy consumption. Most of the multifamily residential buildings built in the 20th century in Central and Eastern Europe do not satisfy the current requirements on energy efficiency. Nationwide measures taken to improve the energy efficiency of these buildings rarely consider their impact on the indoor air quality (IAQ). The objective of the present study was to evaluate the impact of simple energy renovation on IAQ, air exchange rates (AER) and occupant satisfaction in Slovak residential buildings. Three pairs of identical naturally ventilated multifamily residential buildings were examined. One building in each pair was newly renovated, the other was in its original condition. Temperature, relative humidity (RH) and the concentration of carbon dioxide (CO2) were measured in 94 apartments (57%) during one week in the winter. A questionnaire related to perceived air quality, sick building syndrome symptoms and airing habits was filled by the occupants. In a companion experiment, the IAQ was investigated in 20 apartments (50%) of a single residential building before and after its renovation. In this experiment, concentrations of nitrogen dioxide (NO2), formaldehyde and total and individual volatile organic compounds (VOC) were also measured. CO2 concentrations were significantly higher and AERs were lower in the renovated buildings. Formaldehyde concentrations increased after renovation and were positively correlated with CO2 and RH. Energy renovation was associated with lower occupant satisfaction with IAQ. Energy retrofitting efforts should be complemented with improved ventilation in order to avoid adverse effects on IAQ.

  • 29.
    Gavilán, Helena
    et al.
    ICMM/CSIC, Spain.
    Kowalski, Anja
    Micromod Partikeltechnologie GmbH, Germany.
    Heinke, David
    NanoPET Pharma GmbH, Germany.
    Sugunan, Abhilash
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Sommertune, Jens
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Varón, Miriam
    Technical University of Denmark, Denmark.
    Bogart, Lara K.
    University College of London, UK.
    Posth, Oliver
    Physikalisch-Technische Bundesanstalt, Germany.
    Zeng, Lunjie
    Chalmers University of Technology, Gothenburg, Sweden.
    González-Alonso, David
    University of Cantabria, Spain.
    Balceris, Chrsitoph
    Institute of Electrical Measurement and Fundamental Electrical Engineering, Germany.
    Fock, Jeppe
    Technical University of Denmark, Denmark.
    Wetterskog, Erik
    Uppsala University, Sweden.
    Frandsen, Cathrine
    Technical University of Denmark, Denmark.
    Gehrke, Nicole
    NanoPET Pharma GmbH, Germany.
    Grüttner, Cordula
    Micromod Partikeltechnologie GmbH, Germany.
    Fornara, Andrea
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Ludwig, Frank
    Institute of Electrical Measurement and Fundamental Electrical Engineerig, Germany.
    Veintemillas-Verdaguer, Sabino
    Instituto de Ciencia de Materiales de Madrid, ICMM/CSIC, Madrid, Spain.
    Johansson, Christer
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Morales, M. Puerto
    ICMM/CSIC, Madrid, Spain.
    Colloidal Flower-Shaped Iron Oxide Nanoparticles: Synthesis Strategies and Coatings2017In: Particle & particle systems characterization, ISSN 0934-0866, E-ISSN 1521-4117, Vol. 34, no 7, article id 1700094Article in journal (Refereed)
    Abstract [en]

    The assembly of magnetic cores into regular structures may notably influence the properties displayed by a magnetic colloid. Here, key synthesis parameters driving the self-assembly process capable of organizing colloidal magnetic cores into highly regular and reproducible multi-core nanoparticles are determined. In addition, a self-consistent picture that explains the collective magnetic properties exhibited by these complex assemblies is achieved through structural, colloidal, and magnetic means. For this purpose, different strategies to obtain flower-shaped iron oxide assemblies in the size range 25–100 nm are examined. The routes are based on the partial oxidation of Fe(OH)2, polyol-mediated synthesis or the reduction of iron acetylacetonate. The nanoparticles are functionalized either with dextran, citric acid, or alternatively embedded in polystyrene and their long-term stability is assessed. The core size is measured, calculated, and modeled using both structural and magnetic means, while the Debye model and multi-core extended model are used to study interparticle interactions. This is the first step toward standardized protocols of synthesis and characterization of flower-shaped nanoparticles.

  • 30.
    Gebbie, Matthew A.
    et al.
    Stanford University, USA .
    Smith, Alexander M.
    University of Oxford, UK .
    Dobbs, Howard A.
    University of California, Santa Barbara, USA.
    Lee, Alpha A.
    Harvard University, USA.
    Warr, Gregory G.
    University of Sydney, Australia.
    Banquy, Xavier
    Universite de Montreal, Canada.
    Valtiner, Markus
    Max Planck Institut fur Eisenforschung GmbH, Germany.
    Rutland, Mark W.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials. KTH Royal Institute of Technology, Sweden .
    Israelachvili, Jacob N.
    University of California, USA.
    Perkin, Susan
    University of Oxford, UK .
    Atkin, Rob
    University of Newcastle, Australia.
    Long range electrostatic forces in ionic liquids2017In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 53, no 7, p. 1214-1224Article in journal (Refereed)
    Abstract [en]

    Ionic liquids are pure salts that are liquid under ambient conditions. As liquids composed solely of ions, the scientific consensus has been that ionic liquids have exceedingly high ionic strengths and thus very short Debye screening lengths. However, several recent experiments from laboratories around the world have reported data for the approach of two surfaces separated by ionic liquids which revealed remarkable long range forces that appear to be electrostatic in origin. Evidence has accumulated demonstrating long range surface forces for several different combinations of ionic liquids and electrically charged surfaces, as well as for concentrated mixtures of inorganic salts in solvent. The original interpretation of these forces, that ionic liquids could be envisioned as “dilute electrolytes,” was controversial, and the origin of long range forces in ionic liquids remains the subject of discussion. Here we seek to collate and examine the evidence for long range surface forces in ionic liquids, identify key outstanding questions, and explore possible mechanisms underlying the origin of these long range forces. Long range surface forces in ionic liquids and other highly concentrated electrolytes hold diverse implications from designing ionic liquids for energy storage applications to rationalizing electrostatic correlations in biological self-assembly.

  • 31.
    Goesmann, Fred
    et al.
    Max-Planck-Institut für Sonnensystemforschung,Germany..
    Brinckerhoff, William B.
    NASA GSFC, USA..
    Raulin, Francoise
    CNRS, France..
    Goetz, Walter
    Max-Planck-Institut für Sonnensystemforschung, Germany.
    Danell, Ryan M.
    Danell Consulting, USA..
    Getty, Stephanie A.
    NASA GSFC,, USA.
    Siljeström, Sandra
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Mißbach, Helge
    Max-Planck-Institut für Sonnensystemforschung, Germany.
    Steininger, Harald
    Max-Planck-Institut für Sonnensystemforschung, Germany.
    Arevalo, Ricardo D.
    NASA GSFC, USA.
    Buch, Arnaud
    LPGM, France..
    Freissinet, Caroline
    LATMOS/IPSL, France..
    Grubisic, Andrei
    NASA GSFC, USA ; University of Maryland, USA.
    Meierhenrich, Uwe J.
    Université de Nice-Sophia Antipolis, France..
    Pinnick, Veronica T.
    NASA GSFC, USA.
    Stalport, Fabien
    CNRS, France..
    Szopa, Cyriel
    LATMOS/IPSL, France. ; Institut Universitaire de France, France.
    Vago, Jorge L.
    ESA, The Netherlands..
    Lindner, Robert
    ESA, The Netherlands..
    Schulte, Mitchell D.
    NASA Headquarters, USA..
    Brucato, John R.
    INAF—Astrophysical Observatory of Arcetri, Italy..
    Glavin, Danil P.
    NASA GSFC, USA.
    Grand, Noel
    CNRS, France..
    Li, Xiang
    NASA GSFC, USA ; University of Maryland, USA.
    Van Amerom, Frisco H. W.
    Mini-Mass Consulting, USA..
    The Mars Organic Molecule Analyzer (MOMA) Instrument: Characterization of Organic Material in Martian Sediments2017In: Astrobiology, ISSN 1531-1074, E-ISSN 1557-8070, Vol. 17, no 6-7, p. 655-685Article in journal (Refereed)
    Abstract [en]

    The Mars Organic Molecule Analyzer (MOMA) instrument onboard the ESA/Roscosmos ExoMars rover (to launch in July, 2020) will analyze volatile and refractory organic compounds in martian surface and subsurface sediments. In this study, we describe the design, current status of development, and analytical capabilities of the instrument. Data acquired on preliminary MOMA flight-like hardware and experimental setups are also presented, illustrating their contribution to the overall science return of the mission..

  • 32.
    Grady, Moniqa M
    et al.
    Open University, UK ; The Natural History Museum, UK.
    Wright, Ian
    Open University, UK.
    Engrand, Cecile
    University Paris Sud, France.
    Siljeström, Sandra
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    The Rosetta mission and the chemistry of organic species in comet 67P/Churyumov-Gerasimenko2018In: Elements, ISSN 1811-5209, E-ISSN 1811-5217, Vol. 14, no 2, p. 95-100Article in journal (Refereed)
    Abstract [en]

    Comets are regarded as probably the most primitive of solar system objects, preserving a record of the materials from which the solar system aggregated. Key amongst their components are organic compounds - molecules that may trace their heritage to the interstellar medium from which the protosolar nebula eventually emerged. The most recent cometary space mission, Rosetta, carried instruments designed to characterize, in unprecedented detail, the organic species in comet 67P/Churyumov-Gerasimenko (67P). Rosetta was the first mission to match orbits with a comet and follow its evolution over time, and also the first mission to land scientific instruments on a comet surface. Results from the mission revealed a greater variety of molecules than previously identified and indicated that 67P contained both primitive and processed organic entities. 

  • 33.
    Granskog, Viktor
    et al.
    KTH Royal Institute of Technology, Sweden.
    García-Gallego, Sandra
    KTH Royal Institute of Technology, Sweden.
    von Kieseritzky, Johanna
    Karolinska Institutet, Sweden.
    Rosendahl, Jennifer
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Stenlund, Patrik
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Zhang, Yuning
    KTH Royal Institute of Technology, Sweden.
    Petronis, Sarunas
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Lyvén, Benny
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Arner, Marianne
    Karolinska Institutet, Sweden.
    Håkansson, Joakim
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Malkoch, Michael
    KTH Royal Institute of Technology, Sweden.
    High-Performance Thiol–Ene Composites Unveil a New Era of Adhesives Suited for Bone Repair2018In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 28, no 26, article id 1800372Article in journal (Refereed)
    Abstract [en]

    The use of adhesives for fracture fixation can revolutionize the surgical procedures toward more personalized bone repairs. However, there are still no commercially available adhesive solutions mainly due to the lack of biocompatibility, poor adhesive strength, or inadequate fixation protocols. Here, a surgically realizable adhesive system capitalizing on visible light thiol–ene coupling chemistry is presented. The adhesives are carefully designed and formulated from a novel class of chemical constituents influenced by dental resin composites and self-etch primers. Validation of the adhesive strength is conducted on wet bone substrates and accomplished via fiber-reinforced adhesive patch (FRAP) methodology. The results unravel, for the first time, on the promise of a thiol–ene adhesive with an unprecedented shear bond strength of 9.0 MPa and that surpasses, by 55%, the commercially available acrylate dental adhesive system Clearfil SE Bond of 5.8 MPa. Preclinical validation of FRAPs on rat femur fracture models details good adhesion to the bone throughout the healing process, and are found biocompatible not giving rise to any inflammatory response. Remarkably, the FRAPs are found to withstand loads up to 70 N for 1000 cycles on porcine metacarpal fractures outperforming clinically used K-wires and match metal plates and screw implants.

  • 34.
    Gren, Johan A.
    et al.
    Lund University, Sweden.
    Sjövall, Peter
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry, Materials and Surfaces.
    Eriksson, Mats E.
    Lund University, Sweden.
    Sylvestersen, Rene L.
    MUSERUM, Denmark.
    Marone, Frederica
    Paul Scherrer Institute, Switzerland.
    Sigfridsson Clauss, Kajsa G. V.
    MAX IV Laboratory, Sweden.
    Taylor, Gavin J.
    Lund University, Sweden.
    Carlson, Stefan
    MAX IV Laboratory, Sweden.
    Uvdal, Per
    Lund University, Sweden.
    Lindgren, Johan
    Lund University, Sweden.
    Molecular and microstructural inventory of an isolated fossil bird feather from the Eocene Fur Formation of Denmark2017In: Palaeontology, ISSN 0031-0239, E-ISSN 1475-4983, Vol. 60, no 1, p. 73-90Article in journal (Refereed)
    Abstract [en]

    An isolated, yet virtually intact contour feather (FUM-1980) from the lower Eocene Fur Formation of Denmark was analysed using multiple imaging and molecular techniques, including field emission gun scanning electron microscopy (FEG-SEM), X-ray absorption spectroscopy and time-of-flight secondary ion mass spectrometry (ToF-SIMS). Additionally, synchrotron radiation X-ray tomographic microscopy (SRXTM) was employed in order to produce a digital reconstruction of the fossil. Under FEG-SEM, the proximal, plumulaceous part of the feather revealed masses of ovoid microstructures, about 1.7 μm long and 0.5 μm wide. Microbodies in the distal, pennaceous portion were substantially smaller (averaging 0.9 × 0.2 μm), highly elongate, and more densely packed. Generally, the microbodies in both the plumulaceous and pennaceous segments were aligned along the barbs and located within shallow depressions on the exposed surfaces. Biomarkers consistent with animal eumelanins were co-localized with the microstructures, to suggest that they represent remnant eumelanosomes (i.e. eumelanin-housing cellular organelles). Additionally, ToF-SIMS analysis revealed the presence of sulfur-containing organics – potentially indicative of pheomelanins – associated with eumelanin-like compounds. However, since there was no correlation between melanosome morphology and sulfur content, we conclude these molecular structures derive from diagenetically incorporated sulfur rather than pheomelanin. Melanosomes corresponding roughly in both size and morphology with those in the proximal part of FUM-1980 are known from contour feathers of extant parrots (Psittaciformes), an avian clade that has previously been reported from the Fur Formation.

  • 35.
    Hakonen, Aron
    et al.
    RISE - Research Institutes of Sweden. Sensor Visions AB, Sweden.
    Karlsson, Anders
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Lindman, Lena
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Büker, Oliver
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Arrhenius, Karine
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Particles in fuel-grade Liquefied Natural Gas2018In: Journal of Natural Gas Science and Engineering, ISSN 1875-5100, E-ISSN 2212-3865, Vol. 55, p. 350-353Article in journal (Refereed)
    Abstract [en]

    The utilization of Liquefied Natural Gas (LNG) in the heavy-duty transport sector is a convenient and cost-effective step towards a sustainable future. However, there are questions regarding LNG fuel quality and destructive particles for engines. Basically nothing is known about particles in the commercial LNG being fueled today. The gravimetric and SEM-EDX results here demonstrates that there are precarious metal and silicon dioxide particles in fuel-grade LNG that can clog and erode engine parts. Considering these results further research in the direction of this study, including standardized method development, is highly motivated.

  • 36.
    Hakonen, Aron
    et al.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry, Materials and Surfaces. Chalmers University of Technology, Sweden.
    Wang, Fengshao
    University of Science & Technology of China, China.
    Andersson, Per Ola
    Uppsala University, Sweden ; Swedish Defense Research Agency FOI, Sweden.
    Wingfors, Håkan
    Swedish Defense Research Agency FOI, Sweden.
    Rindzevicius, Tomas
    Technical University of Denmark, Denmark.
    Schmidt, Michael S.
    Technical University of Denmark, Denmark.
    Soma, Venugopal Roi
    University of Hyderabad, India.
    Xu, Shicai
    Dezhou University, China .
    Li, YingQi
    University of Science & Technology of China, China.
    Boisen, Anja
    Technical University of Denmark, Denmark.
    Wu, HengAn
    University of Science & Technology of China, China.
    Hand-Held Femtogram Detection of Hazardous Picric Acid with Hydrophobic Ag Nanopillar SERS Substrates and Mechanism of Elasto-Capillarity2017In: ACS Sensors, ISSN 2379-3694, Vol. 2, no 2, p. 198-202Article in journal (Refereed)
    Abstract [en]

    Picric acid (PA) is a severe environmental and security risk due to its unstable, toxic, and explosive properties. It is also challenging to detect in trace amounts and in situ because of its highly acidic and anionic character. Here, we assess sensing of PA under nonlaboratory conditions using surface-enhanced Raman scattering (SERS) silver nanopillar substrates and hand-held Raman spectroscopy equipment. The advancing elasto-capillarity effects are explained by molecular dynamics simulations. We obtain a SERS PA detection limit on the order of 20 ppt, corresponding attomole amounts, which together with the simple analysis methodology demonstrates that the presented approach is highly competitive for ultrasensitive analysis in the field.

  • 37.
    Hakonen, Aron
    et al.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry, Materials and Surfaces. Chalmers University of Technology, Sweden.
    Wang, FengShao
    University of Science & Technology of China, China.
    Andersson, Per Ola
    Swedish Defense Research Agency FOI, Sweden ; Uppsala University, Sweden.
    Wingfors, Håkan
    Swedish Defense Research Agency FOI, Sweden ; .
    Rindzevicius, Tomas
    Technical University of Denmark, Denmark.
    Stenbæk Schmidt, Michael
    Technical University of Denmark, Denmark.
    Rao Soma, Venugopal
    University of Hyderabad, India.
    Xu, Shicai
    Dezhou University, China.
    Li, YingQi
    University of Science & Technology of China, China.
    Boisen, Anja
    Technical University of Denmark, Denmark.
    Wu, HengAn
    University of Science & Technology of China, China.
    Hand-Held Femtogram Detection of Hazardous Picric Acid with Hydrophobic Ag Nanopillar SERS Substrates and Mechanism of Elasto-Capillarity2017In: Sensors, ISSN 1424-8220, E-ISSN 1424-8220, Vol. 2, no 2, p. 1998-202Article in journal (Refereed)
    Abstract [en]

    Picric acid (PA) is a severe environmental and security risk due to its unstable, toxic, and explosive properties. It is also challenging to detect in trace amounts and in situ because of its highly acidic and anionic character. Here, we assess sensing of PA under nonlaboratory conditions using surface-enhanced Raman scattering (SERS) silver nanopillar substrates and hand-held Raman spectroscopy equipment. The advancing elasto-capillarity effects are explained by molecular dynamics simulations. We obtain a SERS PA detection limit on the order of 20 ppt, corresponding attomole amounts, which together with the simple analysis methodology demonstrates that the presented approach is highly competitive for ultrasensitive analysis in the field.

  • 38.
    Haloua, Frederique
    et al.
    Laboratoire national de métrologie et d'essais (LNE), France.
    Bacquart, Thomas
    National Physical Laboratory (NPL), UK.
    Arrhenius, Karine
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Delobelle, Benoit
    MAHYTEC, France.
    Ent, Hugo
    Van Swinden Laboratorium (VSL), Netherlands.
    Metrology for hydrogen energy applications: a project to address normative requirements2018In: Measurement science and technology, ISSN 0957-0233, E-ISSN 1361-6501, Vol. 29, no 3, article id Special Section on the 18th International Congress of Metrology (CIM 2017)Article in journal (Refereed)
    Abstract [en]

    Hydrogen represents a clean and storable energy solution that could meet worldwide energy demands and reduce greenhouse gases emission. The joint research project (JRP) ‘Metrology for sustainable hydrogen energy applications’ addresses standardisation needs through pre- and co-normative metrology research in the fast emerging sector of hydrogen fuel that meet the requirements of the European Directive 2014/94/EU by supplementing the revision of two ISO standards that are currently too generic to enable a sustainable implementation of hydrogen. The hydrogen purity dispensed at refueling points should comply with the technical specifications of ISO 14687-2 for fuel cell electric vehicles. The rapid progress of fuel cell technology now requires revising this standard towards less constraining limits for the 13 gaseous impurities. In parallel, optimized validated analytical methods are proposed to reduce the number of analyses. The study aims also at developing and validating traceable methods to assess accurately the hydrogen mass absorbed and stored in metal hydride tanks; this is a research axis for the revision of the ISO 16111 standard to develop this safe storage technique for hydrogen. The probability of hydrogen impurity presence affecting fuel cells and analytical techniques for traceable measurements of hydrogen impurities will be assessed and new data of maximum concentrations of impurities based on degradation studies will be proposed. Novel validated methods for measuring the hydrogen mass absorbed in hydrides tanks AB, AB2 and AB5 types referenced to ISO 16111 will be determined, as the methods currently available do not provide accurate results. The outputs here will have a direct impact on the standardisation works for ISO 16111 and ISO 14687-2 revisions in the relevant working groups of ISO/TC 197 ‘Hydrogen technologies’.

  • 39.
    Hannestad, Jonas
    et al.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials. Chalmers University of Technology, Sweden.
    Höök, Fredrik
    Chalmers University of Technology, Sweden.
    Sjövall, Peter
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials. Chalmers University of Technology, Sweden.
    Nanometer-scale molecular organization in lipid membranes studied by time-of-flight secondary ion mass spectrometry.2018In: Biointerphases, ISSN 1934-8630, E-ISSN 1559-4106, Vol. 13, no 3, article id 03B408Article in journal (Refereed)
    Abstract [en]

    The organization of lipid membranes plays an important role in a wide range of biological processes at different length scales. Herein, the authors present a procedure based on time-of-flight secondary ion mass spectrometry (ToF-SIMS) to characterize the nanometer-scale ordering of lipids in lipid membrane structures on surfaces. While ToF-SIMS is a powerful tool for label-free analysis of lipid-containing samples, its limited spatial resolution prevents in-depth knowledge of how lipid properties affect the molecular assembly of the membrane. The authors overcome this limitation by measuring the formation of lipid dimers, originating in the same nanometer-sized primary ion impact areas. The lipid dimers reflect the local lipid environment and thus allow us to characterize the membrane miscibility on the nanometer level. Using this technique, the authors show that the chemical properties of the constituting lipids are critical for the structure and organization of the membrane on both the nanometer and micrometer length scales. Our results show that even at lipid surface compositions favoring two-phase systems, lipids are still extracted from solid, gel phase, domains into the surrounding fluid supported lipid bilayer surrounding the gel phase domains. The technique offers a means to obtain detailed knowledge of the chemical composition and organization of lipid membranes with potential application in systems where labeling is not possible, such as cell-derived supported lipid bilayers.

  • 40.
    Hedberg, Yolanda S.
    et al.
    KTH Royal Institute of Technology, Sweden ; Karolinska Institutet, Sweden.
    Hedberg, Jonas F.
    KTH Royal Institute of Technology, Sweden.
    Isaksson, Sara
    KTH Royal Institute of Technology, Sweden.
    Mei, Nanxuan
    KTH Royal Institute of Technology, Sweden.
    Blomberg, Eva
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry, Materials and Surfaces. KTH Royal Institute of Technology, Sweden.
    Wold, Susanna
    KTH Royal Institute of Technology, Sweden.
    Odnevall Wallinder, Inger
    KTH Royal Institute of Technology, Sweden.
    Nanoparticles of WC-Co, WC, Co and Cu of relevance for traffic wear particles – Particle stability and reactivity in synthetic surface water and influence of humic matter2017In: Environmental Pollution, ISSN 0269-7491, E-ISSN 1873-6424, Vol. 224, p. 275-288Article in journal (Refereed)
    Abstract [en]

    Studded tyres made of tungsten carbide cobalt (WC-Co) are in the Northern countries commonly used during the winter time. Tungsten (W)-containing nano- and micron-sized particles have been detected close to busy roads in several European countries. Other typical traffic wear particles consist of copper (Cu). The aims of this study were to investigate particle stability and transformation/dissolution properties of nanoparticles (NPs) of WC-Co compared with NPs of tungsten carbide (WC), cobalt (Co), and Cu. Their physicochemical characteristics (primarily surface oxide and charge) are compared with their extent of sedimentation and metal release in synthetic surface water (SW) with and without two different model organic molecules, 2,3- and 3,4-dihydroxybenzoic acid (DHBA) mimicking certain sorption sites of humic substances, for time periods up to 22 days. The WC-Co NPs possessed a higher electrochemical and chemical reactivity in SW with and without DHBA molecules as compared with NPs of WC, Co, and Cu. Co was completely released from the WC-Co NPs within a few hours of exposure, although it remained adsorbed/bonded to the particle surface and enabled the adsorption of negatively charged DHBA molecules, in contrast with the WC NPs (no adsorption of DHBA). The DHBA molecules were found to rapidly adsorb on the Co and Cu NPs. The sedimentation of the WC and WC-Co NPs was not influenced by the presence of the 2,3- or 3,4-DHBA molecules. A slight influence (slower sedimentation) was observed for the Co NPs, and a strong influence (slower sedimentation) was observed for the Cu NPs in SW with 2,3-DHBA compared with SW alone. The extent of metal release increased in the order: WC < Cu < Co < WC-Co NPs. All NPs released more than 1 wt-% of their metal total mass. The release from the Cu NPs was most influenced by the presence of DHBA molecules.

  • 41.
    Hedman, Johannes
    et al.
    Swedish National Forensic Centre, Sweden ; Lund University, Sweden.
    Lavander, Moa
    National Food Agency, Sweden.
    Salomonsson, Emelie N.
    Swedish Defence Research Agency, Sweden.
    Jinnerot, Tomas
    National Veterinary Institute, Sweden.
    Boiso, Lina
    Swedish National Forensic Centre, Sweden.
    Magnusson, Bertil
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Rådström, Peter
    Lund University, Sweden.
    Validation guidelines for PCR workflows in bioterrorism preparedness, food safety and forensics2018In: Accreditation and Quality Assurance, ISSN 0949-1775, E-ISSN 1432-0517, Vol. 23, no 3, p. 133-144Article in journal (Refereed)
    Abstract [en]

    The polymerase chain reaction (PCR) is the backbone of contemporary DNA/RNA analysis, ideally enabling detection of one or just a few target molecules. However, when analysing food or forensic samples the analytical procedure is often challenged by low amounts of poor quality template molecules and complex matrices. Applying optimised and validated methods in all steps of the analysis workflow, i.e. sampling, sample treatment, DNA/RNA extraction and PCR (including reverse transcription for RNA analysis), is thus necessary to ensure the reliability of analysis. In this paper, we describe how in-house validation can be performed for the different modules of the diagnostic PCR process, providing practical examples as tools for laboratories in their planning of validation studies. The focus is analysis of heterogeneous samples with interfering matrices, with relevance in food testing, forensic DNA analysis, bioterrorism preparedness and veterinary medicine. Our objective is to enable rational in-house validation for reliable and swift quality assurance when results are urgent, for example in the event of a crisis such as a foodborne outbreak or a crime requiring the analysis of a large number of diverse samples. To that end, we explain the performance characteristics associated with method validation from a PCR and biological sample matrix perspective and suggest which characteristics to investigate depending on the type of method to be validated. Also, we include a modular approach to validation within the PCR workflow, aiming at efficient validation and a flexible use of methods.

  • 42.
    Hellström, Anna-Karin
    et al.
    Chalmers, Gothenburg, Sweden.
    de la Motte, Hanna
    RISE - Research Institutes of Sweden, Bioeconomy, Biorefinery and Energy.
    Syrén, Marie
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Nordstierna, Lars
    Bordes, Romain
    Enabling Textile Recycling: On/Off Dyeing2016Conference paper (Other academic)
    Abstract [en]

    Develop a novel family of environmental friendly dispersant for textile coloring embedded an on/off function for closed loop recycling.

  • 43.
    Hickey, C. D.
    et al.
    Teagasc Food Research Centre, Ireland ; University of Limerick, Ireland.
    Diehl, B. W. K.
    Spectral service AG, Germany.
    Nuzzo, Marine
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry, Materials and Surfaces.
    Millqvist-Feurby, Anna
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry, Materials and Surfaces.
    Wilkinson, M. G.
    University of Limerick, Ireland.
    Sheehan, J. J.
    Teagasc Food Research Centre, Ireland.
    Influence of buttermilk powder or buttermilk addition on phospholipid content, chemical and bio-chemical composition and bacterial viability in Cheddar style-cheese2017In: Food Research International, ISSN 0963-9969, E-ISSN 1873-7145, Vol. 102, p. 748-758Article in journal (Refereed)
    Abstract [en]

    The effect of buttermilk powder addition post-curd formation or buttermilk addition to cheese milk on total and individual phospholipid content, chemical composition, enzyme activity, microbial populations and microstructure within Cheddar-style cheese was investigated. Buttermilk or buttermilk powder addition resulted in significant increases in total phospholipid content and their distribution throughout the cheese matrix. Addition of 10% buttermilk powder resulted in higher phospholipid content, moisture, pH and salt in moisture levels, and lower fat, fat in dry matter, L. helveticus and non-starter bacteria levels in cheeses. Buttermilk powder inclusion resulted in lower pH 4.6/Soluble Nitrogen (SN) levels and significantly lower free amino acid levels in 10% buttermilk powder cheeses. Buttermilk addition provided a more porous cheese microstructure with greater fat globule coalescence and increased free fat pools, while also increasing moisture and decreasing protein, fat and pH levels. Addition of buttermilk in liquid or powdered form offers potential for new cheeses with associated health benefits. © 2017 Elsevier Ltd

  • 44.
    Hilchenbach, Martin
    et al.
    Max-Planck-Institut, Germany.
    Fischer, Henning
    Max-Planck-Institut, Germany.
    Langevin, Yves
    CNRS/Université Paris Sud, France.
    Merouane, Sihane
    Max-Planck-Institut, Germany.
    Paquette, John
    Max-Planck-Institut, Germany.
    Rynö, Jouni
    Finnish Meteorological Institute, Finland.
    Stenzel, Oliver
    Max-Planck-Institut, Germany.
    Briois, Christelle
    CNRS/Université d'Orléans, France.
    Kissel, Jochen
    Max-Planck-Institut, Germany.
    Koch, Andreas
    von Hoerner und Sulger GmbH, Schwetzingen, Germany.
    Schulz, Rita
    ESA – ESTEC, The Netherland.
    Silen, Johan
    Finnish Meteorological Institute, Finland.
    Altobelli, Nicolas
    ESA-ESAC, Spain.
    Baklouti, Donia
    CNRS/Université Paris Sud, France.
    Bardyn, Anais
    CNRS/Université d'Orléans, France ; UMR CNRS Université Paris Est Créteil et Université Paris Diderot, France.
    Cottin, Herve
    CNRS/Université d'Orléans, France.
    Engrand, Cecile
    CNRS/Université d'Orléans, France.
    Fray, Nicolas
    UMR CNRS 7583, Université Paris Est Créteil et Université Paris Diderot, France.
    Haerendel, Gerhard
    Max-Planck-Institut, Germany.
    Henkel, Hartmut
    CNRS/Université d'Orléance, France.
    Höfner, Herwig
    Max-Planck-Institut, Germany.
    Hornung, Klaus
    Universität der Bundeswehr LRT-7, Germany.
    Lehto, Harry
    University of Turku, Finland.
    Mellado, Eva M.
    University of Turku, Finland.
    Modica, Paola
    CNRS/Université d'Orléans, France ; UMR CNRS 7583, Université Paris Est Créteil et Université Paris Diderot, France.
    Le Roy, Lena
    University of Bern, Switzerland.
    Siljeström, Sandra
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Steiger, Wolfgang
    RC Seibersdorf Research GmbH Business Field Aerospace Technology, Austria.
    Thirkell, Laurent
    CNRS/Université d'Orléans, France.
    Thomas, Roger
    Finnish Meteorological Institute,Finland.
    Torkar, Klaus
    Austrian Academy of Sciences, Austria.
    Varmuza, Kurt
    Vienna University of Technology, Austria.
    Zaprudin, Boris
    RC Seibersdorf Research GmbH Business Field Aerospace Technology, Austria.
    Mechanical and electrostatic experiments with dust particles collected in the inner coma of comet 67P by COSIMA onboard Rosetta2017In: Philosophical Transactions. Series A: Mathematical, physical, and engineering science, ISSN 1364-503X, E-ISSN 1471-2962, Vol. 375, no 2097Article in journal (Refereed)
    Abstract [en]

    The in situ cometary dust particle instrument COSIMA (COmetary Secondary Ion Mass Analyser) onboard ESA's Rosetta mission has collected about 31 000 dust particles in the inner coma of comet 67P/Churyumov-Gerasimenko since August 2014. The particles are identified by optical microscope imaging and analysed by time-of-flight secondary ion mass spectrometry. After dust particle collection by low speed impact on metal targets, the collected particle morphology points towards four families of cometary dust particles. COSIMA is an in situ laboratory that operates remotely controlled next to the comet nucleus. The particles can be further manipulated within the instrument by mechanical and electrostatic means after their collection by impact. The particles are stored above 0°C in the instrument and the experiments are carried out on the refractory, ice-free matter of the captured cometary dust particles. An interesting particle morphology class, the compact particles, is not fragmented on impact. One of these particles was mechanically pressed and thereby crushed into large fragments. The particles are good electrical insulators and transform into rubble pile agglomerates by the application of an energetic indium ion beam during the secondary ion mass spectrometry analysis. This article is part of the themed issue 'Cometary science after Rosetta'. © 2017 The Authors.

  • 45.
    Hjalmarsson, N.
    et al.
    KTH Royal Institute of Technology, Sweden.
    Atkin, R.
    The University of Newcastle, Australia.
    Rutland, Mark W.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials. KTH Royal Institute of Technology, Sweden.
    Switchable long-range double layer force observed in a protic ionic liquid2017In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 53, no 3, p. 647-650Article in journal (Refereed)
    Abstract [en]

    A repulsive double layer force has been measured for ethylammonium nitrate (EAN) at 373 K and 393 K, which is absent at lower temperatures. This temperature-tuneable change in behaviour is the opposite of recent observations which challenge traditional views of ionicity. This finding thus widens the debate about the very nature of ionic liquids.

  • 46.
    Huang, Hui
    et al.
    Shandong University, China; KTH Royal Institute of Technology, Sweden.
    Dobryden, Illia
    KTH Royal Institute of Technology, Sweden.
    Ihrner, Niklas
    KTH Royal Institute of Technology, Sweden.
    Johansson, Mats
    KTH Royal Institute of Technology, Sweden.
    Ma, Houyi
    Shandong University, China.
    Pan, Jinshan
    KTH Royal Institute of Technology, Sweden.
    Claesson, Per M.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry, Materials and Surfaces. KTH Royal Institute of Technology, Sweden.
    Temperature-dependent surface nanomechanical properties of a thermoplastic nanocomposite2017In: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 494, p. 204-214Article in journal (Refereed)
    Abstract [en]

    In polymer nanocomposites, particle-polymer interactions influence the properties of the matrix polymer next to the particle surface, providing different physicochemical properties than in the bulk matrix. This region is often referred to as the interphase, but detailed characterization of its properties remains a challenge. Here we employ two atomic force microscopy (AFM) force methods, differing by a factor of about 15 in probing rate, to directly measure the surface nanomechanical properties of the transition region between filler particle and matrix over a controlled temperature range. The nanocomposite consists of poly(ethyl methacrylate) (PEMA) and poly(isobutyl methacrylate) (PiBMA) with a high concentration of hydrophobized silica nanoparticles. Both AFM methods demonstrate that the interphase region around a 40-nm-sized particle located on the surface of the nanocomposite could extend to 55-70nm, and the interphase exhibits a gradient distribution in surface nanomechanical properties. However, the slower probing rate provides somewhat lower numerical values for the surface stiffness. The analysis of the local glass transition temperature (T g) of the interphase and the polymer matrix provides evidence for reduced stiffness of the polymer matrix at high particle concentration, a feature that we attribute to selective adsorption. These findings provide new insight into understanding the microstructure and mechanical properties of nanocomposites, which is of importance for designing nanomaterials.

  • 47.
    Huang, Hui
    et al.
    KTH Royal Institute of Technology, Sweden.
    Dobryden, Illia
    KTH Royal Institute of Technology, Sweden.
    Thorén, P -A
    KTH Royal Institute of Technology, Sweden.
    Ejenstam, L.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry, Materials and Surfaces. KTH Royal Institute of Technology, Sweden.
    Pan, J.
    KTH Royal Institute of Technology, Sweden.
    Fielden, M. L.
    KTH Royal Institute of Technology, Sweden.
    Haviland, D. B.
    KTH Royal Institute of Technology, Sweden.
    Claesson, P. M.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry, Materials and Surfaces. KTH Royal Institute of Technology, Sweden.
    Local surface mechanical properties of PDMS-silica nanocomposite probed with Intermodulation AFM2017In: Composites Science And Technology, ISSN 0266-3538, E-ISSN 1879-1050, Vol. 150, p. 111-119Article in journal (Refereed)
    Abstract [en]

    The mechanical properties of polymeric nanocomposites are strongly affected by the nature of the interphase between filler and matrix, which can be controlled by means of surface chemistry. In this report, we utilize intermodulation atomic force microscopy (ImAFM) to probe local mechanical response with nanometer-scale resolution of poly(dimethylsiloxane) (PDMS) coatings with and without 20 wt% of hydrophobic silica nanoparticles. The data evaluation is carried out without inferring any contact mechanics model, and is thus model-independent. ImAFM imaging reveals a small but readily measurable inhomogeneous mechanical response of the pure PDMS surface layer. The analysis of energy dissipation measured with ImAFM showed a lowering of the viscous response due to the presence of the hydrophobic silica nanoparticles in the polymer matrix. An enhanced elastic response was also evident from the in-phase stiffness of the matrix, which was found to increase by a factor of 1.5 in presence of the nanoparticles. Analysis of dissipation energy and stiffness in the immediate vicinity of the nanoparticles provides an estimate of the interphase thickness. Because the local stiffness varies significantly near the nanoparticle, AFM height images contain artifacts that must be corrected in order to reveal the true surface topography. Without such a correction the AFM height images erroneously show that the stiff particles protrude from the surface, whereas corrected images show that they are actually embedded in the matrix and likely covered with a thin layer of polymer.

  • 48.
    Jansson, Anna
    et al.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Carlred, Louise
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Sjövall, Peter
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Borchardt, Per
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Sipilä, Konsta
    VTT, Finland.
    Joki, Harri
    VTT, Finland.
    Surface sensitive analysis for investigation of oxidation profiles in rubber sealing material2018Conference paper (Refereed)
    Abstract [en]

    Oxidation is the dominating degradation process in most polymers during long term use in nuclear power plant (NPP) applications. Under radiation, oxygen diffusion is known to be detrimental for poly-mers at room temperature and it is accelerated by increased temperature. Diffusion limited oxidation (DLO) has an effect to the heterogeneous oxidation behavior of polymers. [1]. During normal service of NPPs the temperature within the containment can be tens of degrees beyond room temperature. Also radiation levels can vary, depending on e.g. the reactor design, typically being less than 10 Gy/h during normal service [2].

    The long-term performance of polymeric materials is obviously best assessed by exposure of test specimens to natural ageing conditions followed by examination of their performance characteristics in terms of changes in physical properties. The testing conditions can be either in-door or out-door envi-ronments, and the first signs of degradation are often detected by testing mechanical properties such as tensile strength and elongation-at-break [3]. Although natural ageing is the most reliable

    exposure method for examining long-term performance, its use is restricted due to the extremely long exposure times required to achieve service lifetimes. In order to decrease the testing time significantly, and thereby achieve more rapid prediction of long-term behaviour of polymeric materials, artificial ac-celerated test methods involving harsher environments are used [4]. However, the accelerated ageing conditions cause at least two kinds of problems. Firstly, the chemistry of degradation can be markedly affected when the conditions of artificial ageing are too harsh. One consequence of this is a poor cor-relation with the changes that occur during natural ageing, resulting in misleading performance data. Secondly, all factors used in artificial ageing to induce chemical degradation and obtain observable physical changes must be accelerated to the same degree. However, neither the factors responsible for the ultimate degradation of a more or less complex polymeric system, nor the effects of their inter-relation are known. Consequently, it is essential that the analytical tools used to follow the ageing are capable of detecting and identifying differences between the employed accelerated tests and the natu-ral ageing already at an early stage of degradation. Moreover, sensitive tools can limit the need for high acceleration factors in artificial ageing.

    During accelerated ageing DLO effects may cause heterogeneous oxidation of the polymer which usu-ally does not occur to the same extent under normal service conditions at NPP. Combined to DLO ef-fects, understanding the combined effects of ionizing radiation and temperature is essential when evaluating the lifetime of polymeric components during normal service life or in Design Based Accident (DBA) situations.

    In order to study the oxygen containing degradation products on the surface compared to the bulk ma-terial a surface sensitive analytical instrument, Time-of-Flight Secondary Ion Mass Spectroscopy (ToF-SIMS), was applied on EPDM samples. The aim is ultimately to evaluate the possibility to use ToF-SIMS in oxidation profile measurements. For comparisons this study includes differential scanning DSC, and Fourier transform infrared Spectroscopy (FTIR) as well as tensile testing.

  • 49.
    Johansson, Kenth S.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry, Materials and Surfaces.
    20 - Surface Modification of Plastics2017In: Applied Plastics Engineering Handbook (Second Edition): Processing, Materials, and Applications / [ed] Kutz, Myer, Elsevier, 2017, p. 443-487Chapter in book (Other academic)
    Abstract [en]

    Abstract This chapter gives an overview of different methods for improving surface properties of plastics. Plastics are inherently hydrophobic, low surface energy materials and thus do not adhere well to other materials. Adhesion improvement is the most common application but other surface characteristics, such as wettability, water- and chemical resistance, nonfouling, tribological behavior, oxygen, and moisture transmission are also addressed. It has been estimated that 70% of the total production of plastic materials must be surface treated prior to processing. The methods range from vacuum to atmospheric pressure, wet to dry, simple to sophisticated, and inexpensive to very costly to obtain the required functional characteristics of plastics. Most methods used today are dry and environmentally sound. The methods presented are roughly divided in surface activation (e.g., plasma, corona, flame, and UV laser) and surface coating (e.g., plasma polymerization, chemical vapor deposition, Parylene, physical vapor deposition) techniques.

  • 50.
    Johansson, Pernilla
    et al.
    RISE - Research Institutes of Sweden, Built Environment, Building Technology.
    Brander, Linus
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Jansson, Anna
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Karlsson, Stefan
    RISE - Research Institutes of Sweden, Built Environment, Building Technology.
    Landel, Pierre
    RISE - Research Institutes of Sweden, Built Environment, Building Technology.
    Svennberg, Kaisa
    Kvalitet hos byggnadsmaterial i cirkulära flöden2017Report (Other academic)
    Abstract [en]

    The aim of the project presented in the report was that construction and demolition waste will be recycled or recycled to a greater extent and at the same time fulfil the quality requirements on the materials.

    The purpose of the project has been to map and compile the knowledge and experience of the technical aspects of circular flows of building materials, focusing on quality issues, identifying new projects that can reduce the amount of construction and demolition waste deposited or burned, as well as creating new networks. There is widespread knowledge in the construction industry about these issues and there are also a wide range of research results in different areas. In the project, knowledge and experience have been gathered through literature studies, workshops and seminars, study visits and interviews.

    The first part of the report discusses general technical experiences and challenges in different parts of the building chain, while challenges for specific material groups are discussed in the second part of the report. These material groups are polymeric materials, flat glass, stone wool, glass wool, plasterboard, crushed concrete, wood and wood-based materials. The report also presents a survey conducted by Optimera among their professional costumers, which aimed at collecting their experiences and views on sustainable construction.

    In general, we can find that there are major challenges in increasing recycling rates for demolition and refurbishment waste. For installation and construction waste, the technical challenges are not as big. Challenges and conditions for increased recycling and reuse with retained good quality vary between different types of materials / products, type of construction project and intended use.

    The report proposes a number of proposals in areas where work can be continued. These include improved / expanded inventory for demolition and refurbishment, routines and sampling methods, proper sorting, handling and storage to ensure the right quality, to provide the ability to separate compound materials, logistics, production technology and quality assurance. The results also show the importance of education, networks and meeting places and that research projects are conducted interdisciplinary. There are good opportunities for increased recycling through cooperation throughout the entire building chain.

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