Ändra sökning
Avgränsa sökresultatet
1234567 1 - 50 av 397
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Träffar per sida
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
Markera
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 1.
    Abbas, S.
    et al.
    Quaid-i-Azam University, Pakistan.
    Imtiaz-ud-Din,
    Quaid-i-Azam University, Pakistan.
    Mehmood, M.
    Quaid-i-Azam University, Pakistan.
    Raheel, A.
    Quaid-i-Azam University, Pakistan.
    Ayub, Rabia
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Bioraffinaderi och energi.
    Zahid, M.
    Higher Education Department Govt. of the Punjab, Pakistan.
    Tahir, M. N.
    University of Sargodha, Pakistan.
    Synthesis and Structural Characterization of Bioactive Ferrocenyl Substituted Hydrazones2021Ingår i: Russian journal of coordination chemistry, ISSN 1070-3284, E-ISSN 1608-3318, Vol. 47, nr 12, s. 891-902Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A series of ferrocenyl substituted hydrazones (I–VII) derived from ferrocene carboxaldehyde and substituted hydrazides have been prepared and characterized by FTIR, 1H NMR spectroscopy, and crystallographic studies. The single-crystal X-ray analysis for III·0.5H2O·0.5CH3CN (CIF file CCDC no. 1968937) further authenticates the structural motif of the synthesized compounds. The C(11) of ferrocene carboxaldehyde is linked with N(1) of the hydrazide moiety with a bond length of 1.283(5) Å, confirming the binding of the two structural units present in the final product. They were preliminarily screened for their antimicrobial activity and demonstrate good results. The free radical scavenging activity for the compounds (III, IV) has been found to be more than 90% when compared with the ascorbic acid. The total antioxidant capacity and total reducing power assays for VI show significant activity whereas the data for the other compounds are also encouraging. Quantum chemical calculations at the DFT level predict that compound II is the softest while VII is the hardest within the series, resultantly II can be used as a synthon for further chemical reactions.

  • 2.
    Adeboye, Peter Temitope
    et al.
    Chalmers University of Technology, Sweden.
    Bettiga, Maurizio
    Chalmers University of Technology, Sweden.
    Aldaeus, Fredrik
    RISE., Innventia.
    Larsson, Per Tomas
    RISE., Innventia.
    Olsson, Lars
    RISE., Innventia. Chalmers University of Technology, Sweden.
    Catabolism of coniferyl aldehyde, ferulic acid and p-coumaric acid by Saccharomyces cerevisiae yields less toxic products2015Ingår i: Microbial Cell Factories, E-ISSN 1475-2859, Vol. 14, nr 1, artikel-id 149Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Lignocellulosic substrates and pulping process streams are of increasing relevance to biorefineries for second generation biofuels and biochemical production. They are known to be rich in sugars and inhibitors such as phenolic compounds, organic acids and furaldehydes. Phenolic compounds are a group of aromatic compounds known to be inhibitory to fermentative organisms. It is known that inhibition of Sacchromyces cerevisiae varies among phenolic compounds and the yeast is capable of in situ catabolic conversion and metabolism of some phenolic compounds. In an approach to engineer a S. cerevisiae strain with higher tolerance to phenolic inhibitors, we selectively investigated the metabolic conversion and physiological effects of coniferyl aldehyde, ferulic acid, and p-coumaric acid in Saccharomyces cerevisiae. Aerobic batch cultivations were separately performed with each of the three phenolic compounds. Conversion of each of the phenolic compounds was observed on time-based qualitative analysis of the culture broth to monitor various intermediate and final metabolites. Result: Coniferyl aldehyde was rapidly converted within the first 24 h, while ferulic acid and p-coumaric acid were more slowly converted over a period of 72 h. The conversion of the three phenolic compounds was observed to involved several transient intermediates that were concurrently formed and converted to other phenolic products. Although there were several conversion products formed from coniferyl aldehyde, ferulic acid and p-coumaric acid, the conversion products profile from the three compounds were similar. On the physiology of Saccharomyces cerevisiae, the maximum specific growth rates of the yeast was not affected in the presence of coniferyl aldehyde or ferulic acid, but it was significantly reduced in the presence of p-coumaric acid. The biomass yields on glucose were reduced to 73 and 54 % of the control in the presence of coniferyl aldehyde and ferulic acid, respectively, biomass yield increased to 127 % of the control in the presence of p-coumaric acid. Coniferyl aldehyde, ferulic acid and p-coumaric acid and their conversion products were screened for inhibition, the conversion products were less inhibitory than coniferyl aldehyde, ferulic acid and p-coumaric acid, indicating that the conversion of the three compounds by Saccharomyces cerevisiae was also a detoxification process. Conclusion: We conclude that the conversion of coniferyl aldehyde, ferulic acid and p-coumaric acid into less inhibitory compounds is a form of stress response and a detoxification process. We hypothesize that all phenolic compounds are converted by Saccharomyces cerevisiae using the same metabolic process. We suggest that the enhancement of the ability of S. cerevisiae to convert toxic phenolic compounds into less inhibitory compounds is a potent route to developing a S. cerevisiae with superior tolerance to phenolic compounds.

    Ladda ner fulltext (pdf)
    fulltext
  • 3.
    Ahmed, Fareed
    et al.
    Linköping University, Sweden.
    Ding, Penghui
    Linköping University, Sweden.
    Ail, Ujwala
    Linköping University, Sweden.
    Warczak, Magdalena
    Linköping University, Sweden.
    Grimoldi, Andrea
    Linköping University, Sweden.
    Ederth, Thomas
    Linköping University, Sweden.
    Håkansson, Karl
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign.
    Vagin, Mikhail
    Linköping University, Sweden.
    Gueskine, Viktor
    Linköping University, Sweden.
    Berggren, Magnus
    Linköping University, Sweden.
    Crispin, Xavier
    Linköping University, Sweden.
    Manufacturing Poly(3,4-Ethylenedioxythiophene) Electrocatalytic Sheets for Large-Scale H2O2 Production2022Ingår i: Advanced Sustainable Systems, ISSN 2366-7486, Vol. 6, nr 1, artikel-id 2100316Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Producing thick films of conducting polymers by a low-cost manufacturing technique would enable new applications. However, removing huge solvent volume from diluted suspension or dispersion (1–3 wt%) in which conducting polymers are typically obtained is a true manufacturing challenge. In this work, a procedure is proposed to quickly remove water from the conducting polymer poly(3,4-ethylenedioxythiophene:poly(4-styrene sulfonate) (PEDOT:PSS) suspension. The PEDOT:PSS suspension is first flocculated with 1 m H2SO4 transforming PEDOT nanoparticles (≈50–500 nm) into soft microparticles. A filtration process inspired by pulp dewatering in a paper machine on a wire mesh with apertures dimension between 60 µm and 0.5 mm leads to thick free-standing films (≈0.5 mm). Wire mesh clogging that hinders dewatering (known as dead-end filtration) is overcome by adding to the flocculated PEDOT:PSS dispersion carbon fibers that aggregate and form efficient water channels. Moreover, this enables fast formation of thick layers under simple atmospheric pressure filtration, thus making the process truly scalable. Thick freestanding PEDOT films thus obtained are used as electrocatalysts for efficient reduction of oxygen to hydrogen peroxide, a promising green chemical and fuel. The inhomogeneity of the films does not affect their electrochemical function. © 2021 The Authors. 

  • 4.
    Ahniyaz, Anwar
    et al.
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign.
    de Meatza, Iratxe
    CIDETEC, Spain.
    Kvasha, Andriy
    CIDETEC, Spain.
    Garcia-Calvo, Oihane
    CIDETEC, Spain.
    Ahmed, Istaq
    Volvo Group Trucks Technology, Sweden.
    Sgroi, Mauro Francesco
    C.R.F. S.C.p.A, Italy.
    Giuliano, Mattia
    C.R.F. S.C.p.A, Italy.
    Dotoli, Matteo
    C.R.F. S.C.p.A, Italy.
    Dumitrescu, Mihaela-Aneta
    Faam Research Center, Italy.
    Jahn, Marcus
    AIT, Austria.
    Zhang, Ningxin
    AIT, Austria.
    Progress in solid-state high voltage lithium-ion battery electrolytes2021Ingår i: Advances in Applied Energy, ISSN 2666-7924, Vol. 4, artikel-id 100070Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Developing high specific energy Lithium-ion (Li-ion) batteries is of vital importance to boost the production of efficient electric vehicles able to meet the customers’ expectation related to the electric range of the vehicle. One possible pathway to high specific energy is to increase the operating voltage of the Li-ion cell. Cathode materials enabling operation above 4.2 V are available. The stability of the positive electrode-electrolyte interface is still the main bottleneck to develop high voltage cells. Moreover, important research efforts are devoted to the substitution of graphite anodes with Li metal: this would improve the energy density of the cell dramatically. The use of metallic lithium is prevented by the dendrite growth during charge, with consequent safety problems. To suppress the formation of dendrites solid-state electrolytes are considered the most promising approach. For these reasons the present review summarizes the most recent research efforts in the field of high voltage solid-state electrolytes for high energy density Li-ion cells.

  • 5.
    Alriksson, Björn
    et al.
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Processum.
    Eskilsson, Martin
    Holmen, Sweden.
    Johansson, Emma
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Processum.
    Lapidot, Shaul
    Melodea, Israel.
    Norström, Markus
    RISE., SP – Sveriges Tekniska Forskningsinstitut.
    Schultz-Eklund, Ola
    Holmen, Sweden .
    Shkedi, Yoram
    Melodea, Israel.
    Svedberg, Anna
    MoRe Research, Sweden.
    Svensson, Stefan
    MoRe Research, Sweden.
    Swerin, Agne
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Material och ytteknik.
    Europe’s first pilot facility for cellulose nanocrystals (CNC)2016Ingår i: Annual Surface and Materials Chemistry Symposium and Materials for tomorrow (ASMCS 2016), 2016Konferensbidrag (Refereegranskat)
  • 6.
    Amanipour, M.
    et al.
    Tarbiat Modares University, Iran.
    Heidari, M.
    Sharif University of Technology, Iran.
    Walberg, Martin
    RISE Research Institutes of Sweden.
    Comparison of hydrogen permeation and structural properties of a microporous silica membrane and a dense BaCe0.9Y0.1O3-δ (BCY) perovskite membrane2022Ingår i: Results in Materials, ISSN 2590-048X, Vol. 15, artikel-id 100314Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Silica composite membranes and BaCe0.9Y0.1O3-δ (BCY) perovskite membranes were successfully synthesized to separate hydrogen in an equimolar mixture of H2, CH4, CO, and CO2 at temperature range of 500–900 °C and pressure difference of 1 bar. The phase structure of both membranes was characterized by X-ray diffraction (XRD). Thermogravimetric analysis (TGA) was used to evaluate phase stability of perovskite membrane. FESEM images confirmed graded structure of silica membrane and uniform, dense structure of perovskite membrane. H2 permeation in semi-dense silica layer deposited on alumina substrate indicated that permeation in top selective layer follows a diffusion mechanism which is based on jumps between solubility sites. On the other hand, low permeation rates of around 10−8 mol m−2 s−1 Pa−1 in perovskite membranes revealed a proton-electron conductivity mechanism which occurs through dense structures. Increasing hydrogen separation factor (SF) in gas mixture by increasing deposition time from 3.5 h to 6 h in silica composite membrane confirms formation of crack-free selective layer; however, this factor is still lower than SF of 0.97–0.99 in perovskite membranes. A set of gas-permeability data is collected at the laboratory scale for the statistical characterization of both membrane types (P01, S01) to provide a dataset from which one can assess statistical scaling features displayed by the data and their scaling increments. 

  • 7.
    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, Biovetenskap och material, Kemi och material. 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, Biovetenskap och material, Kemi och material. KTH Royal Institute of Technology, Sweden.
    Dedinaite, Andra
    RISE - Research Institutes of Sweden, Biovetenskap och material, Kemi och material. KTH Royal Institute of Technology, Sweden.
    Effect of solvent quality and chain density on normal and frictional forces between electrostatically anchored thermoresponsive diblock copolymer layers2017Ingår i: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 487, s. 88-96Artikel i tidskrift (Refereegranskat)
    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.

  • 8.
    Andersson, Anton
    et al.
    Luleå University of Technology, Sweden.
    Brander, Linus
    RISE Research Institutes of Sweden, Material och produktion, Metodik för produktframtagning.
    Lennartsson, Andreas
    Luleå University of Technology, Sweden.
    Roos, Åke
    Boliden AB, Sweden.
    Engström, Fredrik
    Luleå University of Technology, Sweden.
    A Method for Synthesizing Iron Silicate Slags to Evaluate Their Performance as Supplementary Cementitious Materials2023Ingår i: Applied Sciences, E-ISSN 2076-3417, Vol. 13, nr 14, artikel-id 8357Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Utilizing iron silicate copper slag as supplementary cementitious material (SCM) is a means to improve resource efficiency and lower the carbon dioxide emissions from cement production. Despite multiple studies on the performance of these slags in SCM applications, the variations in cooling procedure, grinding, and methods for evaluating reactivity limit the ability to assess the influence of chemical composition on reactivity from the literature data. In this study, a methodology was developed to synthesize iron silicate slags, which were then evaluated for their inherent reactivity using the R3 calorimeter-based experiments. The results demonstrated that laboratory-scale granulation produced the same reactivity as industrially granulated slag. Furthermore, a synthesized triplicate sample showed high repeatability. Based on these two aspects, this method can be used to systematically study the influence of chemical composition on the inherent reactivity of iron silicate slags while producing results that are directly translatable to industrial slags. © 2023 by the authors.

  • 9.
    Andersson Ersman, Peter
    et al.
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    Boda, Ulrika
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    Petsagkourakis, Ioannis
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    Åhlin, Jessica
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    Posset, Uwe
    Fraunhofer, Germany.
    Schott, Marco
    Fraunhofer, Germany.
    Brooke, Robert
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    Reflective and Complementary Transmissive All-Printed Electrochromic Displays Based on Prussian Blue2023Ingår i: Advanced Engineering Materials, ISSN 1438-1656, E-ISSN 1527-2648, Vol. 25, nr 6, artikel-id 2201299Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    By combining the electrochromic (EC) properties of Prussian blue (PB) and poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS), complementary EC displays manufactured by slot-die coating and screen printing on flexible plastic substrates are reported. Various display designs have been realized, resulting in displays operating in either transmissive or reflective mode. For the transmission mode displays, the color contrast is enhanced by the complementary switching of the two EC electrodes PB and PEDOT:PSS. Both electrodes are either exhibiting a concurrent colorless or blue appearance. For the displays operating in reflection mode, a white opaque electrolyte is used in conjunction with the EC properties of PB, resulting in a display device switching between a fully white state and a blue-colored state. The developments of the different device architectures, that either operate in reflection or transmission mode, demonstrate a scalable manufacturing approach of all-printed EC displays that may be used in a large variety of Internet of Things applications. © 2022 The Authors. 

  • 10.
    Andersson, Helene
    et al.
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Food and Bioscience. Chalmers University of Technology, Sweden.
    Stading, Mats
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Food and Bioscience. Chalmers University of Technology, Sweden.
    Hjärtstam, Johan
    Chalmers University of Technology, Sweden; Astra Zeneca R&D Mölndal, Sweden.
    von Corswant, Christian
    Chalmers University of Technology, Sweden; Astra Zeneca R&D Mölndal, Sweden.
    Larsson, Anette
    Chalmers University of Technology, Sweden.
    Effects of Molecular Weight on Phase Separated Coatings for Controlled Release of Drugs2013Ingår i: Annual Transactions of the Nordic Rheology Society, s. 249-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Phase separated films with controlled porosity were made from ethyl cellulose (EC) and 30% w/w hydroxypropyl cellulose (HPC). The molecular weight of EC can be used to modify the mass transfer rate through coatings by effects on microstructure of the film. Processing conditions are, however, affected by the solution rheology, which could influence the film quality when using different molecular weights.

  • 11.
    Andersson, Martin
    et al.
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign.
    Norinder, Ulf
    Stockholm University, Sweden.
    Chavan, Swapnil
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Kemisk och farmaceutisk toxikologi.
    Cotgreave, Ian
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Kemisk och farmaceutisk toxikologi.
    In Silico Prediction of Eye Irritation Using Hansen Solubility Parameters and Predicted pKa Values2023Ingår i: ATLA (Alternatives to Laboratory Animals), ISSN 0261-1929, Vol. 51, nr 3, s. 204-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    An in silico method has been developed that permits the binary differentiation between pure liquids causing serious eye damage or eye irritation, and pure liquids with no need for such classification, according to the UN GHS system. The method is based on the finding that the Hansen Solubility Parameters (HSP) of a liquid are collectively important predictors for eye irritation. Thus, by applying a two-tier approach in which in silico predicted pKa values (firstly) and a trained model based solely on in silico-predicted HSP data (secondly) were used, we have developed, and validated, a fully in silico approach for predicting the outcome of a Draize test (in terms of UN GHS Cat. 1/Cat. 2A/Cat. 2B or UN GHS No Cat.) with high validation set performance (sensitivity = 0.846, specificity = 0.818, balanced accuracy = 0.832) using SMILES only. The method is applicable to pure non-ionic liquids with molecular weight below 500 g/mol, fewer than six hydrogen bond donors (e.g. nitrogen–hydrogen or oxygen–hydrogen bonds) and fewer than eleven hydrogen bond acceptors (e.g. nitrogen or oxygen atoms). Due to its fully in silico characteristics, this method can be applied to pure liquids that are still at the desktop design stage and not yet in production.

  • 12.
    Ankerfors, Mikael
    et al.
    RISE., Innventia.
    Duker, Elisabeth
    BillerudKorsnäs AB, Sweden.
    Lindström, Tom
    RISE., Innventia.
    Topo-chemical modification of fibres by grafting of carboxymethyl cellulose in pilot scale2013Ingår i: Nordic Pulp and Paper Research Journal, ISSN 0283-2631 , nr 1, s. 6-14Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The aim of this study was to graft carboxymethyl cellulose (CMC) on to bleached softwood kraft pulp at temperatures below 100°C and to do a pilot paper machine trial in order to examine the influence of the CMC on dewatering, sheet formation and mechanical properties. During the pilot trial, one CMC grafted pulp was compared to a pulp with 3 different refining degrees. It was shown that CMC-grafting improves the mechanical properties of paper with only a minor effect on the sheet density. It was also shown that the CMC grafting is less detrimental to dewatering than refining and at a certain tensile index a higher dry content after pressing could be reached. The formation number of the paper produced in the FEX trial was not significantly affected by the addition of CMC.

  • 13.
    Appelquist, Karin
    et al.
    RISE - Research Institutes of Sweden, Samhällsbyggnad, CBI Betonginstitutet.
    Mueller, Urs
    RISE - Research Institutes of Sweden, Samhällsbyggnad, CBI Betonginstitutet.
    Trägårdh, Jan
    RISE - Research Institutes of Sweden, Samhällsbyggnad, CBI Betonginstitutet.
    Detection of potential alkali-silica reactivity of aggregates from Sweden2017Konferensbidrag (Övrigt vetenskapligt)
  • 14.
    Arrhenius, Karine
    et al.
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Kemi.
    Brown, Andrew S.
    NPL National Physical Laboratory, UK.
    van der Veen, Adriaan M. H.
    VSL Dutch Metrology Institute, Netherlands.
    Suitability of different containers for the sampling and storage of biogas and biomethane for the determination of the trace-level impurities - A review2016Ingår i: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 902, s. 22-32Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    The traceable and accurate measurement of biogas impurities is essential in order to robustly assess compliance with the specifications for biomethane being developed by CEN/TC408. An essential part of any procedure aiming to determinate the content of impurities is the sampling and the transfer of the sample to the laboratory. Key issues are the suitability of the sample container and minimising the losses of impurities during the sampling and analysis process. In this paper, we review the state-of-the-art in biogas sampling with the focus on trace impurities. Most of the vessel suitability studies reviewed focused on raw biogas. Many parameters need to be studied when assessing the suitability of vessels for sampling and storage, among them, permeation through the walls, leaks through the valves or physical leaks, sorption losses and adsorption effects to the vessel walls, chemical reactions and the expected initial concentration level. The majority of these studies looked at siloxanes, for which sampling bags, canisters, impingers and sorbents have been reported to be fit-for-purpose in most cases, albeit with some limitations. We conclude that the optimum method requires a combination of different vessels to cover the wide range of impurities commonly found in biogas, which have a wide range of boiling points, polarities, water solubilities, and reactivities. The effects from all the parts of the sampling line must be considered and precautions must be undertaken to minimize these effects. More practical suitability tests, preferably using traceable reference gas mixtures, are needed to understand the influence of the containers and the sampling line on sample properties and to reduce the uncertainty of the measurement.

  • 15.
    Arrhenius, Karine
    et al.
    RISE Research Institutes of Sweden, Material och produktion, Kemi och Tillämpad mekanik.
    Francini, Lorena
    RISE Research Institutes of Sweden, Material och produktion, Kemi och Tillämpad mekanik.
    Fischer, Andreas
    RISE Research Institutes of Sweden, Material och produktion, Kemi och Tillämpad mekanik.
    Büker, Oliver
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik.
    Arques, Laurent
    AP2E, France.
    Comparison of optical feedback cavity enhanced absorption spectroscopy and gas chromatography for the measurement of the main components and impurities in biogas, landfill gas, biomethane and carbon dioxide streams2023Ingår i: Measurement science and technology, ISSN 0957-0233, E-ISSN 1361-6501, Vol. 34, nr 9, artikel-id 095011Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this study, we evaluated the performances of a custom-built optical feedback cavity enhanced absorption spectroscopy (OFCEAS) instrument for the determination of the composition of energy gases, focusing on methane and carbon dioxide as main components, and carbon monoxide as impurities, in comparison with the well-established, validated, and traceable gas chromatographic method. A total of 115 real sample gases collected in biogas plants or landfills were analyzed using with both techniques over a period of 12 months. The comparison of the techniques showed that the virtual model which allows the measurement, needs to be optimized using real samples of varied compositions. The OFCEAS measurement technique was found to be capable of measuring both the main components and a trace component in different matrices; to within a 2% measurement uncertainty (higher than the gas chromatograph/thermal conductivity detector (GC/TCD) method). The OFCEAS method exhibits a very fast response, does not require daily calibration, and can be implemented online. The agreements between the OFCEAS technique and the GC/TCD method show that the drift of the OFCEAS instruments remains acceptable in the long term as long as no change is made to the virtual model. Matrix effects were observed, and those need to be taken into consideration when analyzing different types of samples. © 2023 The Author(s). Published by IOP Publishing Ltd.

  • 16.
    Assenhöj, Maria
    et al.
    Linköping University, Sweden.
    Eriksson, Peter
    Linköping University, Sweden.
    Dönnes, Pierre
    SciCross AB, Sweden.
    Ljunggren, Stefan
    Linköping University, Sweden.
    Marcusson-Ståhl, Maritha
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Kemiska processer och läkemedel.
    Du Rietz, Anna
    Linköping University, Sweden.
    Uvdal, Kajsa
    Linköping University, Sweden.
    Karlsson, Hanna
    Linköping University, Sweden.
    Cederbrant, Karin
    RISE Research Institutes of Sweden.
    Protein interaction, monocyte toxicity and immunogenic properties of cerium oxide crystals with 5% or 14% gadolinium, cobalt oxide and iron oxide nanoparticles–an interdisciplinary approach2021Ingår i: Nanotoxicology, ISSN 1743-5390, E-ISSN 1743-5404, Vol. 15, nr 8, s. 1035-1038Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Metal oxide nanoparticles are widely used in both consumer products and medical applications, but the knowledge regarding exposure-related health effects is limited. However, it is challenging to investigate nanoparticle interaction processes with biological systems. The overall aim of this project was to improve the possibility to predict exposure-related health effects of metal oxide nanoparticles through interdisciplinary collaboration by combining workflows from the pharmaceutical industry, nanomaterial sciences, and occupational medicine. Specific aims were to investigate nanoparticle-protein interactions and possible adverse immune reactions. Four different metal oxide nanoparticles; CeOx nanocrystals with 5% or 14% Gd, Co3O4, and Fe2O3, were characterized by dynamic light scattering and high-resolution transmission electron microscopy. Nanoparticle-binding proteins were identified and screened for HLA-binding peptides in silico. Monocyte interaction with nanoparticle–protein complexes was assessed in vitro. Herein, for the first time, immunogenic properties of nanoparticle-binding proteins have been characterized. The present study indicates that especially Co3O4-protein complexes can induce both ‘danger signals’, verified by the production of inflammatory cytokines and simultaneously bind autologous proteins, which can be presented as immunogenic epitopes by MHC class II. The clinical relevance of these findings should be further evaluated to investigate the role of metal oxide nanoparticles in the development of autoimmune disease. The general workflow identified experimental difficulties, such as nanoparticle aggregate formation and a lack of protein-free buffers suitable for particle characterization, protein analyses, as well as for cell studies. This confirms the importance of future interdisciplinary collaborations. © 2021 The Author(s). 

  • 17.
    Athley, Karin
    et al.
    RISE., Innventia.
    Granlöf, Lars
    RISE., Innventia.
    Söderberg, Daniel
    RISE., Innventia.
    Ström, Göran
    RISE., Innventia.
    Optimizing the benefit of retention chemicals2014Konferensbidrag (Refereegranskat)
    Abstract [en]

    Pre-flocculation of filler has been tested as a concept for improving the retention of filler and the strength properties of the sheet. The impact of the size of the filler floes on the mechanical retentionin a fibre network was investigated using a modified laboratory hand sheet former. The mechanical retention was found to increase linearly with both particle size and grammage of the fibre web. These results were confirmed in a full scale production trial on the FEX pilot paper machine at Innventia. Here different filler floe sizes were created through different chemical pre-flocculation strategies. The particle size in the flow to the headbox was measured with FBRM, and a linear relation between particle size and filler retention was found. Corresponding linear relation was seen in a pilot trial when adding filler and retention aid conventionally. This implies that mechanical retention constitute an important part of the filler retention not only upon pre-flocculation but also with conventional addition of filler and retention aid. Thus, the particle size before the headbox can be a good indicator of the retention level. For the conventional application of a two component retention aid system, the increased filler retention correlated to impaired formation and decreased sheet strength. On the contrary, pre-flocculation led to an increase in both sheet strength and filler retention, demonstrating the advantage of pre-flocculating filler.

  • 18.
    Ayub, Rabia
    et al.
    Uppsala University, Sweden.
    Bakouri, O. E.
    Jorner, K.
    Solà, M.
    Ottosson, H.
    Can Baird's and Clar's Rules Combined Explain Triplet State Energies of Polycyclic Conjugated Hydrocarbons with Fused 4nπ- and (4n + 2)π-Rings?2017Ingår i: Journal of Organic Chemistry, ISSN 0022-3263, E-ISSN 1520-6904, Vol. 82, nr 12, s. 6327-6340Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Compounds that can be labeled as "aromatic chameleons" are π-conjugated compounds that are able to adjust their π-electron distributions so as to comply with the different rules of aromaticity in different electronic states. We used quantum chemical calculations to explore how the fusion of benzene rings onto aromatic chameleonic units represented by biphenylene, dibenzocyclooctatetraene, and dibenzo[a,e]pentalene modifies the first triplet excited states (T1) of the compounds. Decreases in T1 energies are observed when going from isomers with linear connectivity of the fused benzene rings to those with cis- or trans-bent connectivities. The T1 energies decreased down to those of the parent (isolated) 4nπ-electron units. Simultaneously, we observe an increased influence of triplet state aromaticity of the central 4n ring as given by Baird's rule and evidenced by geometric, magnetic, and electron density based aromaticity indices (HOMA, NICS-XY, ACID, and FLU). Because of an influence of triplet state aromaticity in the central 4nπ-electron units, the most stabilized compounds retain the triplet excitation in Baird π-quartets or octets, enabling the outer benzene rings to adapt closed-shell singlet Clar π-sextet character. Interestingly, the T1 energies go down as the total number of aromatic cycles within a molecule in the T1 state increases. 

  • 19.
    Ayub, Rabia
    et al.
    Uppsala University, Sweden.
    El Bakouri, O.
    Smith, J. R.
    Jorner, K.
    Ottosson, H.
    Triplet State Baird Aromaticity in Macrocycles: Scope, Limitations, and Complications2021Ingår i: Journal of Physical Chemistry A, ISSN 1089-5639, E-ISSN 1520-5215, Vol. 125, nr 2, s. 570-584Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The aromaticity of cyclic 4nπ-electron molecules in their first ππ∗ triplet state (T1), labeled Baird aromaticity, has gained growing attention in the past decade. Here we explore computationally the limitations of T1 state Baird aromaticity in macrocyclic compounds, [n]CM's, which are cyclic oligomers of four different monocycles (M = p-phenylene (PP), 2,5-linked furan (FU), 1,4-linked cyclohexa-1,3-diene (CHD), and 1,4-linked cyclopentadiene (CPD)). We strive for conclusions that are general for various DFT functionals, although for macrocycles with up to 20 π-electrons in their main conjugation paths we find that for their T1 states single-point energies at both canonical UCCSD(T) and approximative DLPNO-UCCSD(T) levels are lowest when based on UB3LYP over UM06-2X and UCAM-B3LYP geometries. This finding is in contrast to what has earlier been observed for the electronic ground state of expanded porphyrins. Yet, irrespective of functional, macrocycles with 2,5-linked furans ([n]CFU's) retain Baird aromaticity until larger n than those composed of the other three monocycles. Also, when based on geometric, electronic and energetic aspects of aromaticity, a 3[n]CFU with a specific n is more strongly Baird-aromatic than the analogous 3[n]CPP while the magnetic indices tell the opposite. To construct large T1 state Baird-aromatic [n]CM's, the design should be such that the T1 state Baird aromaticity of the macrocyclic perimeter dominates over a situation with local closed-shell Hückel aromaticity of one or a few monocycles and semilocalized triplet diradical character. Monomers with lower Hückel aromaticity in S0 than benzene (e.g., furan) that do not impose steric congestion are preferred. Structural confinement imposed by, e.g., methylene bridges is also an approach to larger Baird-aromatic macrocycles. Finally, by using the Zilberg-Haas description of T1 state aromaticity, we reveal the analogy to the Hückel aromaticity of the corresponding closed-shell dications yet observe stronger Hückel aromaticity in the macrocyclic dications than Baird aromaticity in the T1 states of the neutral macrocycles. © 2021 The Authors.

  • 20.
    Ayub, Rabia
    et al.
    Uppsala University, Sweden.
    Jorner, K.
    Ottosson, H.
    The silacyclobutene ring: An indicator of triplet state Baird-aromaticity2017Ingår i: Inorganics, ISSN 2304-6740, Vol. 5, nr 4, artikel-id 91Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Baird's rule tells that the electron counts for aromaticity and antiaromaticity in the first ππ* triplet and singlet excited states (T1 and S1) are opposite to those in the ground state (S0). Our hypothesis is that a silacyclobutene (SCB) ring fused with a [4n]annulene will remain closed in the T1 state so as to retain T1 aromaticity of the annulene while it will ring-open when fused to a [4n + 2]annulene in order to alleviate T1 antiaromaticity. This feature should allow the SCB ring to function as an indicator for triplet state aromaticity. Quantum chemical calculations of energy and (anti)aromaticity changes along the reaction paths in the T1 state support our hypothesis. The SCB ring should indicate T1 aromaticity of [4n]annulenes by being photoinert except when fused to cyclobutadiene, where it ring-opens due to ring-strain relief. © 2017 by the authors.

  • 21.
    Ayub, Rabia
    et al.
    Uppsala University, Sweden.
    Papadakis, R.
    Jorner, K.
    Zietz, B.
    Ottosson, H.
    Cyclopropyl Group: An Excited-State Aromaticity Indicator?2017Ingår i: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 23, nr 55, s. 13684-13695Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The cyclopropyl (cPr) group, which is a well-known probe for detecting radical character at atoms to which it is connected, is tested as an indicator for aromaticity in the first ππ* triplet and singlet excited states (T1 and S1). Baird's rule says that the π-electron counts for aromaticity and antiaromaticity in the T1 and S1 states are opposite to Hückel's rule in the ground state (S0). Our hypothesis is that the cPr group, as a result of Baird's rule, will remain closed when attached to an excited-state aromatic ring, enabling it to be used as an indicator to distinguish excited-state aromatic rings from excited-state antiaromatic and nonaromatic rings. Quantum chemical calculations and photoreactivity experiments support our hypothesis; calculated aromaticity indices reveal that openings of cPr substituents on [4n]annulenes ruin the excited-state aromaticity in energetically unfavorable processes. Yet, polycyclic compounds influenced by excited-state aromaticity (e.g., biphenylene), as well as 4nπ-electron heterocycles with two or more heteroatoms represent limitations. 

  • 22.
    Babi, Mouhanad
    et al.
    McMaster University, Canada.
    Palermo, Anthony
    University of Toronto, Canada.
    Abitbol, Tiffany
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign.
    Fatona, Ayodele
    McMaster University, Canada.
    Jarvis, Victoria
    McMaster Analytical X-ray Diffraction Facility, Canada.
    Nayak, Akanksha
    McMaster University, Canada.
    Cranston, Emily
    University of British Colombia, USA.
    Moran-Mirabal, Jose
    McMaster University, Canada.
    Visualization of nanostructural dislocations in microcrystalline cellulose fibrils through super-resolution fluorescence microscopy2021Ingår i: Microscopy and Microanalysis, ISSN 1431-9276, E-ISSN 1435-8115, Vol. 27, nr S1, s. 854-Artikel i tidskrift (Refereegranskat)
  • 23.
    Badal Tejedor, Maria
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Biovetenskap och material, Kemi och material. KTH Royal Institute of Technology, Sweden.
    Niklas, Nordgren
    RISE - Research Institutes of Sweden (2017-2019), Biovetenskap och material, Kemi och material.
    Schuleit, Michael
    Novartis Pharma AG, Switzerland.
    Pazesh, Samaneh
    Uppsala University, Sweden.
    Alderborn, Göran
    Uppsala University, Sweden.
    Millqvist-Fureby, Anna
    RISE - Research Institutes of Sweden (2017-2019), Biovetenskap och material, Kemi och material.
    Rutland, Mark W.
    RISE - Research Institutes of Sweden (2017-2019), Biovetenskap och material, Kemi och material. KTH Royal Institute of Technology, Sweden.
    Determination of interfacial amorphicity in functional powders2017Ingår i: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 33, nr 4, s. 920-926Artikel i tidskrift (Refereegranskat)
    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.

  • 24.
    Barwick, Vicki
    et al.
    LGC Ltd, UK.
    Ellison, Stephen L. R.
    LGC Ltd, UK.
    Gjengedal, Elin
    NTNU Norwegian University of Life Sciences, Norway.
    Magnusson, Bertil
    RISE - Research Institutes of Sweden, Biovetenskap och material, Kemi och material.
    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 challenges2017Ingår i: Accreditation and Quality Assurance, ISSN 0949-1775, E-ISSN 1432-0517, Vol. 22, nr 5, s. 253-263Artikel i tidskrift (Refereegranskat)
    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.

  • 25.
    Belaineh, Dagmawi
    et al.
    Linköping University, Sweden.
    Andreasen, Jens W
    DTU Technical University of Denmark, Denmark.
    Palisaitis, Justinas
    Linköping University, Sweden.
    Malti, Abdellah
    KTH Royal institute of Technology, Sweden.
    Håkansson, Karl
    RISE - Research Institutes of Sweden, Bioekonomi, Bioraffinaderi och energi.
    Wågberg, Lars
    KTH Royal institute of Technology, Sweden.
    Crispin, Xavier
    Linköping university, Sweden.
    Engquist, Isak
    Linköping university, Sweden.
    Berggren, Magnus
    Linköping university, Sweden.
    Controlling the Organization of PEDOT:PSS on Cellulose Structures2019Ingår i: ACS Applied Polymer Materials, Vol. 1, nr 9, s. 2342-2351Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Composites of biopolymers and conducting polymers are emerging as promising candidates for a green technological future and areactively being explored in various applications, such as in energy storage ,bioelectronics, and thermoelectrics. While the device characteristics of these composites have been actively investigated, there is limited knowledge concerning the fundamental intracomponent interactions and the modes of molecular structuring. Here, by use of cellulose and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), it is shown that the chemical and structural makeup of the surfaces of the composite components are critical factors that determine the materials organization at relevant dimensions. AFM, TEM, and GIWAXS measurements show that when mixedwith cellulose nanofibrils, PEDOT:PSS organizes into continuous nanosized beadlike structures with an average diameter of 13 nm on the nanofibrils. In contrast, when PEDOT:PSS is blended with molecular cellulose, a phase-segregated conducting network morphology is reached, with a distinctly relatively lower electric conductivity. These results provide insight into the mechanisms ofPEDOT:PSS crystallization and may have significant implications for the design of conducting biopolymer composites for a vast array of applications.

  • 26.
    Belaineh Yilma, Dagmawi
    et al.
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    Brooke, Robert
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    Sani, Negar
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    Say, Mehmet
    Linköping University, Sweden.
    Håkansson, Karl MO
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    Engquist, Isak
    Linköping University, Sweden.
    Berggren, Magnus
    Linköping University, Sweden.
    Edberg, Jesper
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    Printable carbon-based supercapacitors reinforced with cellulose and conductive polymers2022Ingår i: Journal of Energy Storage, ISSN 2352-152X, E-ISSN 2352-1538, Vol. 50, artikel-id 104224Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Sustainable electrical energy storage is one of the most important scientific endeavors of this century. Battery and supercapacitor technologies are here crucial, but typically the current state of the art suffers from either lack of large-scale production possibilities, sustainability or insufficient performance and hence cannot match growing demands in society. Paper and cellulosic materials are mature scalable templates for industrial roll-to-roll production. Organic materials, such as conducting polymers, and carbon derivatives are materials that can be synthesized or derived from abundant sources. Here, we report the combination of cellulose, PEDOT:PSS and carbon derivatives for bulk supercapacitor electrodes adapted for printed electronics. Cellulose provides a mesoscopic mesh for the organization of the active ingredients. Furthermore, the PEDOT:PSS in combination with carbon provides superior device characteristics when comparing to the previously standard combination of activated carbon and carbon black. PEDOT:PSS acts as a mixed ion-electron conducting glue, which physically binds activated carbon particles together, while at the same time facilitating swift transport of both electrons and ions. A surprisingly small amount (10%) of PEDOT:PSS is needed to achieve an optimal performance. This work shows that cellulose added to PEDOT:PSS-carbon enables high-performing, mechanically stable, printed supercapacitor electrodes using a combination of printing methods.

  • 27.
    Benavente-Araoz, Fabian
    et al.
    KTH Royal Institute of Technology, Sweden.
    Ko, Jing
    KTH Royal Institute of Technology, Sweden.
    Lundblad, Anders Olof
    RISE Research Institutes of Sweden.
    Ekström, Henrik
    KTH Royal Institute of Technology, Sweden; COMSOL AB, Sweden.
    Lindbergh, Göran
    KTH Royal Institute of Technology, Sweden.
    An Aging Study of NCA/Si-Graphite Lithium-Ion Cells for Off-Grid Photovoltaic Systems in Bolivia2021Ingår i: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 168, nr 10, artikel-id 100541Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Performance and aging of lithium-ion 18650 cylindrical cells containing NCA and Si-graphite composite electrodes are investigated during long-term low current rate (∼0.1C) cycling protocol resembling charge/discharge profile of off-grid photovoltaic battery system. The cells are cycled within 30% and 75% state-of-charge ranges (SOC) with low, middle and high cut-off voltages. Electrochemical impedance spectroscopy data of full cylindrical cells exhibit severe aging for cells that have been cycled at higher cut-off voltage of 4.2 V. Symmetric cell impedance from each electrode shows that aging of NCA is dominant over aging of Si-graphite. Using a Newman-based impedance model, the NCA symmetrical cells' impedance spectra are parameterized to evaluate the aging modes. The resulting parameterization confirms increased particles' surface film resistance due to possible electrolyte oxidation and tortuosity increase at high cut-off voltages. Cycling the cells with middle and low cut-off voltages causes few significant changes when compared to calendar-aged samples. This opens up the possibility to significantly increase battery lifetime for small photovoltaic battery systems in rural areas of Bolivia. © 2021 The Author(s). 

  • 28.
    Bengtsson, Jenny
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Bioekonomi, Biobaserade material. Chalmers University of Technology, Sweden.
    Jedvert, Kerstin
    RISE - Research Institutes of Sweden (2017-2019), Material och produktion, IVF.
    Hedlund, Artur
    RISE - Research Institutes of Sweden (2017-2019), Material och produktion, IVF.
    Köhnke, Tobias
    RISE - Research Institutes of Sweden (2017-2019), Material och produktion, IVF.
    Theliander, Hans
    Chalmers University of Technology, Sweden.
    Mass transport and yield during spinning oflignin-cellulose carbon fiber precursors2019Ingår i: Holzforschung, ISSN 0018-3830, E-ISSN 1437-434X, Vol. 73, nr 5, s. 509-516Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Lignin, a substance considered as a residue in biomass and ethanol production, has been identified as a renewable resource suitable for making inexpensive carbon fibers (CFs), which would widen the range of possible applications for light-weight CFs reinforced composites. Wet spinning of lignin-cellulose ionic liquid solutions is a promising method for producing lignin-based CFs precursors. However, wet-spinning solutions containing lignin pose technical challenges that have to be solved to enable industrialization. One of these issues is that a part of the lignin leaches into the coagulation liquid, which reduces yield and might complicate solvent recovery. In this work, the mass transport during coagulation is studied in depth using a model system and trends are confirmed with spinning trials. It was discovered that during coagulation, efflux of ionic liquid is not hindered by lignin concentration in solution and the formed cellulose network will enclose soluble lignin. Consequently, a high total concentration of lignin and cellulose in solution is advantageous to maximize yield. This work provides a fundamental understanding on mass transport during coagulation of lignin-cellulose solutions, crucial information when designing new solution-based fiber forming processes.

  • 29.
    Benselfelt, T.
    et al.
    KTH Royal Institute of Technology, Sweden; Nanyang Technological University, Singapore.
    Kummer, N.
    Empa Swiss Federal Laboratories for Materials Science and Technology, Switzerland; ETH Zürich, Switzerland.
    Nordenström, M.
    KTH Royal Institute of Technology, Sweden.
    Fall, Andreas
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign.
    Nyström, G.
    Empa Swiss Federal Laboratories for Materials Science and Technology, Switzerland; ETH Zürich, Switzerland.
    Wågberg, L.
    KTH Royal Institute of Technology, Sweden.
    The Colloidal Properties of Nanocellulose2023Ingår i: ChemSusChem, ISSN 1864-5631, E-ISSN 1864-564X, Vol. 16, nr 8, s. e202201955-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Nanocelluloses are anisotropic nanoparticles of semicrystalline assemblies of glucan polymers. They have great potential as renewable building blocks in the materials platform of a more sustainable society. As a result, the research on nanocellulose has grown exponentially over the last decades. To fully utilize the properties of nanocelluloses, a fundamental understanding of their colloidal behavior is necessary. As elongated particles with dimensions in a critical nanosize range, their colloidal properties are complex, with several behaviors not covered by classical theories. In this comprehensive Review, we describe the most prominent colloidal behaviors of nanocellulose by combining experimental data and theoretical descriptions. We discuss the preparation and characterization of nanocellulose dispersions, how they form networks at low concentrations, how classical theories cannot describe their behavior, and how they interact with other colloids. We then show examples of how scientists can use this fundamental knowledge to control the assembly of nanocellulose into new materials with exceptional properties. We hope aspiring and established researchers will use this Review as a guide. © 2023 The Authors. 

  • 30.
    Berg, Robert
    et al.
    RISE - Research Institutes of Sweden, Biovetenskap och material, Process- och farmaceutisk utveckling.
    Bergman, Jan
    Karolinska Institute, Sweden.
    Synthesis of thieno[2,3-b]indole-2,3-diones and their ring expansions induced by diazomethane2017Ingår i: Tetrahedron, ISSN 0040-4020, E-ISSN 1464-5416, Vol. 73, nr 38, s. 5654-5658Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Indole-2-thione 3 reacted quickly with oxalyl chloride to yield thieno[2,3-b]indole-2,3-dione 4 together with the isomer thiazolo[3,2-a]indole-2,3-dione 5. These thieno[2,3-b]indole-2,3diones underwent ring expansions when treated with diazomethane and e.g. thieno[2,3-b]indole-2,3-dione 4 gave the thiopyrano derivative 16, after two insertions.

  • 31. Bergenstråhle, M.
    et al.
    Wohlert, J.
    Larsson, Per Tomas
    RISE., STFI-Packforsk.
    Mazeau, K.
    Berglund, L. A.
    Dynamics of cellulose - Water interfaces: NMR spin - Lattice relaxation times calculated from atomistic computer simulations2008Ingår i: Journal of Physical Chemistry B, ISSN 1520-6106, E-ISSN 1520-5207, Journal of Physical Chemistry B, Vol. 112, nr 9, s. 2590-2595Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Solid-state nuclear magnetic resonance (CP/MAS 13C NMR) spectroscopy has often been used to study cellulose structure, but some features of the cellulose NMR spectrum are not yet fully understood. One such feature is a doublet around 84 ppm, a signal that has been proposed to originate from C4 atoms at cellulose fibril surfaces. The two peaks yield different T1, differing by approximately a factor of 2 at 75 MHz. In this study, we calculate T1 from C4-H4 vector dynamics obtained from molecular dynamics computer simulations of cellulose I β-water interfacial systems. Calculated and experimentally obtained T1 values for C4 atoms in surface chains fell within the same order of magnitude, 3-20 s. This means that the applied force field reproduces relevant surface dynamics for the cellulose-water interface sufficiently well. Furthermore, a difference in T1 of about a factor of 2 in the range of Larmor frequencies 25-150 MHz was found for C4 atoms in chains located on top of two different crystallographic planes, namely, (110) and (110). A previously proposed explanation that the C4 peak doublet could derive from surfaces parallel to different crystallographic planes is herewith strengthened by computationally obtained evidence. Another suggested basis for this difference is that the doublet originates from C4 atoms located in surface anhydro-glucose units with hydroxymethyl groups pointing either inward or outward. This was also tested within this study but was found to yield no difference in calculated T1.

  • 32. Bergenstråhle-Wohlert, M.
    et al.
    Berglund, L.A.
    Brady, J.W.
    Larsson, P.T.
    RISE., Innventia.
    Westlund, P.-O.
    Wohlert, J.
    Concentration enrichment of urea at cellulose surfaces: Results from molecular dynamics simulations and NMR spectroscopy2012Ingår i: Cellulose, ISSN 0969-0239, E-ISSN 1572-882X, nr 1, s. 1-12Artikel i tidskrift (Refereegranskat)
  • 33.
    Berglin, Mattias
    et al.
    RISE Research Institutes of Sweden, Material och produktion, Metodik för produktframtagning. University of Gothenburg, Sweden.
    Cavanagh, Jorunn Pauline
    Amicoat A/S, Norway; UiT The Arctic University of Norway, Norway.
    Caous, Josefin Seth
    RISE Research Institutes of Sweden, Material och produktion, Metodik för produktframtagning.
    Thakkar, Balmukund Sureshkumar
    Amicoat A/S, Norway.
    Vasquez, Jeddah Marie
    RISE Research Institutes of Sweden, Material och produktion, Metodik för produktframtagning.
    Stensen, Wenche
    UiT The Arctic University of Norway, Norway.
    Lyvén, Benny
    RISE Research Institutes of Sweden, Material och produktion, Metodik för produktframtagning.
    Svendsen, John-Sigurd
    Amicoat A/S, Norway; UiT The Arctic University of Norway, Norway.
    Svenson, Johan
    RISE Research Institutes of Sweden, Material och produktion.
    Flexible and Biocompatible Antifouling Polyurethane Surfaces Incorporating Tethered Antimicrobial Peptides through Click Reactions2024Ingår i: Macromolecular Bioscience, ISSN 1616-5187, E-ISSN 1616-5195, Vol. 4, artikel-id 2300425Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Efficient, simple antibacterial materials to combat implant-associated infections are much in demand. Herein, the development of polyurethanes, both cross-linked thermoset and flexible and versatile thermoplastic, suitable for “click on demand” attachment of antibacterial compounds enabled via incorporation of an alkyne-containing diol monomer in the polymer backbone, is described. By employing different polyolic polytetrahydrofurans, isocyanates, and chain extenders, a robust and flexible material comparable to commercial thermoplastic polyurethane is prepared. A series of short synthetic antimicrobial peptides are designed, synthesized, and covalently attached in a single coupling step to generate a homogenous coating. The lead material is shown to be biocompatible and does not display any toxicity against either mouse fibroblasts or reconstructed human epidermis according to ISO and OECD guidelines. The repelling performance of the peptide-coated materials is illustrated against colonization and biofilm formation by Staphylococcus aureus and Staphylococcus epidermidis on coated plastic films and finally, on coated commercial central venous catheters employing LIVE/DEAD staining, confocal laser scanning microscopy, and bacterial counts. This study presents the successful development of a versatile and scalable polyurethane with the potential for use in the medical field to reduce the impact of bacterial biofilms. 

    Ladda ner fulltext (pdf)
    fulltext
  • 34. Bergstrm, E.M.
    et al.
    Salmen, L.
    RISE., Innventia.
    Kochumalayil, J.
    Berglund, L.
    Plasticized xyloglucan for improved toughness: Thermal and mechanical behaviour2012Ingår i: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, nr 4, s. 2532-2537Artikel i tidskrift (Refereegranskat)
  • 35.
    Berta, Marco
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Biovetenskap och material, Jordbruk och livsmedel.
    Koelewijn, Ingrid
    University of Applied Sciences HAS Den Bosch, Netherlands.
    Johansson, Kalle
    Lyckeby Starch AB, Sweden.
    Stading, Mats
    RISE - Research Institutes of Sweden (2017-2019), Biovetenskap och material, Jordbruk och livsmedel. Chalmers University of Technology, Sweden.
    Effect of cellulose-based hydrocolloids and starch chemical modification on the rheology of gluten-free dough2017Ingår i: Annual Transactions of the Nordic Rheology Society, Vol. 25, s. 77-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study was carried out to evaluate the effect of cellulose-based hydrocolloids on the rheology of flour doughs based on corn starch and potato starch. Adding cellulosebased hydrocolloids or a chemically modified waxy starch to this gluten-free dough imparted a shear-thinning behavior similar to that of wheat flour dough.

  • 36.
    Berta, Marco
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Biovetenskap och material, Jordbruk och livsmedel.
    Moser, Josefine
    RISE - Research Institutes of Sweden (2017-2019), Biovetenskap och material, Jordbruk och livsmedel.
    Lopez-Sanchez, Patricia
    RISE - Research Institutes of Sweden (2017-2019), Biovetenskap och material, Jordbruk och livsmedel.
    Stading, Mats
    RISE - Research Institutes of Sweden (2017-2019), Biovetenskap och material, Jordbruk och livsmedel. Chalmers University of Technology, Sweden.
    Modelling the continuous relaxation time spectrum of aqueous xanthan solutions using two commercial softwares2018Ingår i: Annual Transactions of the Nordic Rheology Society, Vol. 26, s. 183-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    ABSTRACT The continuous relaxation time spectrum was modelled from the mechanical spectrum of a xanthan aqueous solution both using the TA Instruments TRIOS® software, and with the rheology software IRIS®1 . Two types of calculation were applied to obtain the relaxation modes since the software bundles used in this study base the calculation upon two different algorithms, named “parsimonious” as it models continuous relaxation spectra using a minimum number of modes to obtain continuous relaxation times2 , and a nonlinear regularization method that provides a larger spectrum with several modes3 . The results were overall comparable but slightly different for long relaxation times.

  • 37.
    Besharat, Zahra
    et al.
    KTH Royal Institute of Technology, Sweden.
    Wakeham, Deborah
    KTH Royal Institute of Technology, Sweden.
    Johnson, C. Magnus
    KTH Royal Institute of Technology, Sweden.
    Luengo, Gustavo S.
    L’Oréal Research and Innovation, France.
    Greaves, Andrew
    L’Oréal Research and Innovation, France.
    Odnevall Wallinder, Inger
    KTH Royal Institute of Technology, Sweden.
    Göthelid, Mats
    KTH Royal Institute of Technology, Sweden.
    Rutland, Mark W.
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Life Science. KTH Royal Institute of Technology, Sweden.
    Mixed monolayers of alkane thiols with polar terminal group on gold: Investigation of structure dependent surface properties2016Ingår i: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 484, s. 279-290Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Adsorption of thiols with cationic or anionic terminal group on gold has been studied from mixed solutions of 11-Amino-1-undecanethiol (AUT) and 3-Mercaptopropionic acid (MPA) using Quartz Crystal Microbalance with Dissipation (QCM-D), X-ray Photoelectron Spectroscopy (XPS), atomic force microscopy (AFM) and contact angles. The goal is to probe the nature of such layers, and the additivity or otherwise of the pH responsiveness, with a view to evaluate their suitability as smart materials. For each of the two pure (unmixed) cases, ordered molecular monolayers are formed with sulfur binding to gold and the alkane chain pointing out from the surface as expected. Adsorption from the thiol mixtures, however, leads to a more complex behaviour. The surface concentration of thiols from the mixtures, as determined by QCM-D, is considerably lower than for the pure cases and it reaches a minimum at a 3:1 MPA/AUT relative concentration in the solution. The XPS results confirm a reduction in adsorbed amount in mixtures with the lowest overall intensity for the 3:1 ratio. Monolayers formed from mixtures display a wettability which is much lower and less pH sensitive. Collectively these results confirm that for adsorption from mixed systems, the configuration is completely different. Complex formation in the mixed solutions leads to the adsorption of molecules parallel to the surface in an axially in-plane configuration. This parallel layer of thiols is mechanically relatively robust to nano-shaving based on AFM measurements. These results will have a significant impact on the design of biomimetic surface coatings particularly when mixtures of oppositely charged molecules are present on the surface, as is commonly the case in biological, proteinaceous surfaces (e.g. hair and skin).

  • 38.
    Bełdowski, Piotr
    et al.
    Bydgoszcz University of Science & Technology, Poland; KTH Royal Institute of Technology, Sweden.
    Przybyłek, Maciej
    Nicolaus Copernicus University, Poland.
    Raczyński, Przemysław
    University of Silesia, Poland.
    Dedinaite, Andra
    RISE Research Institutes of Sweden. KTH Royal Institute of Technology, Sweden.
    Górny, Krzysztof
    University of Silesia, Poland.
    Wieland, Florian
    Helmholtz-Zentrum Hereon Institute for metallic Biomaterials, Germany.
    Dendzik, Zbigniew
    University of Silesia, Poland.
    Sionkowska, Alina
    Nicolaus Copernicus University, Poland.
    Claesson, Per M
    KTH Royal Institute of Technology, Sweden.
    Albumin–hyaluronan interactions: Influence of ionic composition probed by molecular dynamics2021Ingår i: International Journal of Molecular Sciences, ISSN 1661-6596, E-ISSN 1422-0067, Vol. 22, nr 22, artikel-id 12360Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The lubrication mechanism in synovial fluid and joints is not yet fully understood. Nevertheless, intermolecular interactions between various neutral and ionic species including large macromolecular systems and simple inorganic ions are the key to understanding the excellent lubrication performance. An important tool for characterizing the intermolecular forces and their structural consequences is molecular dynamics. Albumin is one of the major components in synovial fluid. Its electrostatic properties, including the ability to form molecular complexes, are closely related to pH, solvation, and the presence of ions. In the context of synovial fluid, it is relevant to describe the possible interactions between albumin and hyaluronate, taking into account solution composition effects. In this study, the influence of Na+, Mg2+, and Ca2+ ions on human serum albumin–hyaluronan interactions were examined using molecular dynamics tools. It was established that the presence of divalent cations, and especially Ca2+, contributes mostly to the increase of the affinity between hyaluronan and albumin, which is associated with charge compensation in negatively charged hyaluronan and albumin. Furthermore, the most probable binding sites were structurally and energetically characterized. The indicated moieties exhibit a locally positive charge which enables hyaluronate binding (direct and water mediated). © 2021 by the authors

  • 39.
    Björklund Jansson, Marianne
    et al.
    RISE., Innventia.
    Nilvebrant, N. -O
    Wood Extractives2009Ingår i: Wood Chemistry and Wood Biotechnology, Walter de Gruyter, 2009, s. 147-171Kapitel i bok, del av antologi (Refereegranskat)
  • 40.
    Blomqvist, Per
    et al.
    RISE - Research Institutes of Sweden, Säkerhet och transport.
    Sandinge, Anna
    RISE - Research Institutes of Sweden, Säkerhet och transport.
    Experimental evaluation of fire toxicity test methods2018Rapport (Övrigt vetenskapligt)
    Abstract [en]

    An experimental evaluation of the most common bench-scale tests methods for fire toxicity was conducted by RISE Fire Research. The background of the work was the on-going discussion in the fire community on the applicability and relevance of these test methods.

    The test methods included in the programme were the ISO/TS 19700 steady-state tube furnace (SSTF), the controlled atmosphere cone calorimeter (CACC), and the EN 45545-2 smoke chamber test (SC). In these tests the production of selected toxic gases was quantitatively analysed using FTIR. Tests for the measurement of toxic gas production were made with eleven different materials used as test specimens, both combustible and non-combustible materials. The materials were commercially available insulation products provided by EURIMA, the sponsor of the project. These materials should not be regarded as typical or fully representative of a product category.

    The evaluation of the results from the different test methods was divided into combustible test specimens and non-combustible test specimens. That was because the test conditions in the first case are greatly influenced by the combustion behaviour of the test specimen, while in the second case the test conditions are more constant.

    A general observation was that there in many cases was correlation between both species composition and level of toxic gas species yields between test methods when the combustion conditions were similar. In cases where yields differed significantly it could in most cases be explained by clear differences in test conditions.

    For combustible materials it was concluded that the SSTF offers the best means for conducting tests at pre-decided and controlled flaming combustion conditions. The CACC does not give steady-state flaming combustion and the influence of vitiation was limited in the tests made. The SC generally accumulates a mixture of gases from both flaming and non-flaming combustion periods in a test, and the yields measured do not in those cases represent any specific combustion stage.

    For non-combustible materials a general observation was that any of the test methods investigated in principle could be used since the influence on the test conditions from the material itself is limited compared to combustible materials. However, there were specific properties and limitations of the different test methods observed that are important to consider.

    Ladda ner fulltext (pdf)
    RISE Report 2018_40
  • 41.
    Boda, Ulrika
    et al.
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara. Linköping University, Sweden.
    Strandberg, Jan
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    Eriksson, Jens
    Linköping University, Sweden.
    Liu, Xianjie
    Linköping University, Sweden.
    Beni, Valerio
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    Tybrandt, Klas
    Linköping University, Sweden.
    Screen-Printed Corrosion-Resistant and Long-Term Stable Stretchable Electronics Based on AgAu Microflake Conductors2023Ingår i: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 15, nr 9, s. 12372-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    High-throughput production methods such as screen printing can bring stretchable electronics out of the lab into the market. Most stretchable conductor inks for screen printing are based on silver nanoparticles or flakes due to their favorable performance-to-cost ratio, but silver is prone to tarnishing and corrosion, thereby limiting the stability of such conductors. Here, we report on a cost-efficient and scalable approach to resolve this issue by developing screen printable inks based on silver flakes chemically coated by a thin layer of gold. The printed stretchable AgAu conductors reach a conductivity of 8500 S cm-1, remain conductive up to 250% strain, show excellent corrosion and tarnishing stability, and are used to demonstrate wearable LED and NFC circuits. The reported approach is attractive for smart clothing, as the long-term functionality of such devices is expected in a variety of environments. © 2023 The Authors.

  • 42.
    Bogdanova, E.
    et al.
    Malmö University, Sweden.
    Lages, S.
    Malmö University, Sweden; Lund University, Sweden.
    Phan-Xuan, T.
    Malmö University, Sweden; Lund University, Sweden: NovoNordiskA/S, Denmark.
    Kamal, M. A.
    Malmö University, Sweden; Lund University, Sweden.
    Terry, A.
    Lund University, Sweden.
    Millqvist-Fureby, Anna
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Kemiska processer och läkemedel.
    Kocherbitov, V.
    Malmö University, Sweden.
    Lysozyme-Sucrose Interactions in the Solid State: Glass Transition, Denaturation, and the Effect of Residual Water2023Ingår i: Molecular Pharmaceutics, ISSN 1543-8384, E-ISSN 1543-8392Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The freeze-drying of proteins, along with excipients, offers a solution for increasing the shelf-life of protein pharmaceuticals. Using differential scanning calorimetry, thermogravimetric analysis, sorption calorimetry, and synchrotron small-angle X-ray scattering (SAXS), we have characterized the properties at low (re)hydration levels of the protein lysozyme, which was freeze-dried together with the excipient sucrose. We observe that the residual moisture content in these samples increases with the addition of lysozyme. This results from an increase in equilibrium water content with lysozyme concentration at constant water activity. Furthermore, we also observed an increase in the glass transition temperature (Tg) of the mixtures with increasing lysozyme concentration. Analysis of the heat capacity step of the mixtures indicates that lysozyme does not participate in the glass transition of the sucrose matrix; as a result, the observed increase in the Tg of the mixtures is the consequence of the confinement of the amorphous sucrose domains in the interstitial space between the lysozyme molecules. Sorption calorimetry experiments demonstrate that the hydration behavior of this formulation is similar to that of the pure amorphous sucrose, while the presence of lysozyme only shifts the sucrose transitions. SAXS analysis of amorphous lysozyme-sucrose mixtures and unfolding of lysozyme in this environment show that prior to unfolding, the size and shape of lysozyme in a solid sucrose matrix are consistent with its native state in an aqueous solution. The results obtained from our study will provide a better understanding of the low hydration behavior of protein-excipient mixtures and support the improved formulation of biologics. © 2023 The Authors. 

  • 43.
    Bogdanova, Ekaterina
    et al.
    Biofilms research center for Biointerfaces, Sweden; Malmö University, Sweden.
    Millqvist-Fureby, Anna
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Kemiska processer och läkemedel.
    Kocherbitov, Vitaly
    Biofilms research center for Biointerfaces, Sweden; Malmö University, Sweden.
    Hydration enthalpies of amorphous sucrose, trehalose and maltodextrins and their relationship with heat capacities.2021Ingår i: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 23, nr 26, s. 14433-14448Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The mechanisms of glass transitions and the behavior of small solute molecules in a glassy matrix are some of the most important topics of modern thermodynamics. Water plays an important role in the physical and chemical stability of lyophilized biologics formulations, in which glassy carbohydrates act as cryoprotectants and stabilizers. In this study, sorption calorimetry was used for simultaneous measurements of water activity and the enthalpy of water sorption by amorphous sucrose, trehalose and maltodextrins. Moreover, the heat capacity of these carbohydrates in mixtures with water was measured by DSC in a broad range of water contents. The hydration enthalpies of glassy sucrose, trehalose and maltodextrins are exothermic, and the enthalpy change of water-induced isothermal glass transitions is higher for small molecules. The partial molar enthalpy of mixing of water in slow experiments is about -18 kJ mol-1, but less exothermic in the case of small molecules at fast hydration scan rates. By measuring the heat capacities of disaccharides and maltodextrins as a function of water content, we separated the contributions of carbohydrates and water to the total heat capacities of the mixtures. The combination of these data allowed testing of thermodynamic models describing the hydration-induced glass transitions. The heat capacity changes calculated by the fitting of the hydration enthalpy data for disaccharides are in good agreement with the heat capacity data obtained by DSC, while for maltodextrins, the effect of sub-Tg transitions should be taken into account. Combining the data obtained by different techniques, we found a distinct difference in the behavior of water in glassy polymers compared to that in glassy disaccharides. By understanding the behavior of water in glassy carbohydrates, these results can be used to improve the design of freeze-dried formulations of proteins and probiotics.

  • 44.
    Bogdanova, Ekaterina
    et al.
    Malmö University, Sweden; Biofilms research center for Biointerfaces, Sweden; NextBioForm Competence Centre, Sweden.
    Millqvist-Fureby, Anna
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Kemiska processer och läkemedel.
    Kocherbitov, Vitaly
    Malmö University, Sweden; Biofilms research center for Biointerfaces, Sweden; NextBioForm Competence Centre, Sweden.
    Influence of Cooling Rate on Ice Crystallization and Melting in Sucrose-Water System2022Ingår i: Journal of Pharmaceutical Sciences, ISSN 0022-3549, E-ISSN 1520-6017, Vol. 111, nr 7, s. 2030-2037Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The ice crystallization and melting in systems where the equilibrium state is difficult to reach is one of the growing areas in pharmaceutical freeze-drying research. The quality of the final freeze-dried product depends on the parameters of the cooling step, which affect the ice nucleation and growth. In this paper, we present a DSC study of ice crystallization and melting in a sucrose-water system. Using two different types of thermal cycles, we examine the influence of cooling and heating rates on the thermal behavior of sucrose-water solutions with water contents between 50 and 100 wt%. The DSC results show that low cooling rates provide crystallization at higher temperatures and lead to lower amount of non-freezing water. Consequently, the glass transition and ice melting properties observed upon heating depend on the cooling conditions in the preceding step. Based on the experimental results, we investigate the reasons for the existence of the two steps on DSC heating curves in sucrose-water systems: the glass transition step and the onset of ice melting. We show that diffusion of water can be the limiting factor for ice growth and melting in the sucrose-water system when the amorphous phase is in a liquid state. In particular, when the diffusion coefficient drops below 10−14 m2/sec, the ice crystals growth or melting becomes strongly suppressed even above the glass transition temperature. Understanding the diffusion limitations in the sucrose-water system can be used for the optimization of the freeze-drying protocols for proteins and probiotics. © 2022 The Authors

  • 45.
    Boge, Lukas
    et al.
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Life Science. Chalmers University of Technology, Sweden.
    Bysell, Helena
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Life Science.
    Ringstad, Lovisa
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Life Science.
    Wennman, David
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Process Development, Analys och fastfas.
    Umerska, Anita
    University of Angers, France.
    Cassisa, Viviane
    CHU Angers, France.
    Eriksson, Jonny
    Uppsala University, Sweden.
    Joly-Guillou, Marie-Laure
    CHU Angers, France.
    Edwards, Katarina
    Uppsala University, Sweden.
    Andersson, Martin
    Chalmers University of Technology, Sweden.
    Lipid-based liquid crystals as carriers for antimicrobial peptides: Phase behavior and antimicrobial effect2016Ingår i: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 32, nr 17, s. 4217-4228Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The number of antibiotic-resistant bacteria is increasing worldwide, and the demand for novel antimicrobials is constantly growing. Antimicrobial peptides (AMPs) could be an important part of future treatment strategies of various bacterial infection diseases. However, AMPs have relatively low stability, because of proteolytic and chemical degradation. As a consequence, carrier systems protecting the AMPs are greatly needed, to achieve efficient treatments. In addition, the carrier system also must administrate the peptide in a controlled manner to match the therapeutic dose window. In this work, lyotropic liquid crystalline (LC) structures consisting of cubic glycerol monooleate/water and hexagonal glycerol monooleate/oleic acid/water have been examined as carriers for AMPs. These LC structures have the capability of solubilizing both hydrophilic and hydrophobic substances, as well as being biocompatible and biodegradable. Both bulk gels and discrete dispersed structures (i.e., cubosomes and hexosomes) have been studied. Three AMPs have been investigated with respect to phase stability of the LC structures and antimicrobial effect: AP114, DPK-060, and LL-37. Characterization of the LC structures was performed using small-angle X-ray scattering (SAXS), dynamic light scattering, ζ-potential, and cryogenic transmission electron microscopy (Cryo-TEM) and peptide loading efficacy by ultra performance liquid chromatography. The antimicrobial effect of the LCNPs was investigated in vitro using minimum inhibitory concentration (MIC) and time-kill assay. The most hydrophobic peptide (AP114) was shown to induce an increase in negative curvature of the cubic LC system. The most polar peptide (DPK-060) induced a decrease in negative curvature while LL-37 did not change the LC phase at all. The hexagonal LC phase was not affected by any of the AMPs. Moreover, cubosomes loaded with peptides AP114 and DPK-060 showed preserved antimicrobial activity, whereas particles loaded with peptide LL-37 displayed a loss in its broad-spectrum bactericidal properties. AMP-loaded hexosomes showed a reduction in antimicrobial activity.

  • 46.
    Boge, Lukas
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Biovetenskap och material, Yta, process och formulering. Chalmers University of Technology, Sweden.
    Hallstensson, Karin
    RISE - Research Institutes of Sweden (2017-2019), Biovetenskap och material, Yta, process och formulering.
    Ringstad, Lovisa
    RISE - Research Institutes of Sweden (2017-2019), Biovetenskap och material, Yta, process och formulering.
    Johansson, Jenny
    RISE - Research Institutes of Sweden (2017-2019), Biovetenskap och material, Kemi och material.
    Andersson, Therese
    RISE - Research Institutes of Sweden (2017-2019), Biovetenskap och material, Kemi och material.
    Davoudi, Mina
    Lund University, Sweden.
    Larsson, Per Tomas
    RISE - Research Institutes of Sweden (2017-2019), Biovetenskap och material, Kemi och material.
    Mahlapuu, Margit
    Promore Pharma AB, Sweden; University of Gothenburg, Sweden.
    Håkansson, Joakim
    RISE - Research Institutes of Sweden (2017-2019), Biovetenskap och material, Kemi och material.
    Andersson, Martin
    Chalmers University of Technology, Sweden.
    Cubosomes for topical delivery of the antimicrobial peptide LL-372019Ingår i: European journal of pharmaceutics and biopharmaceutics, ISSN 0939-6411, E-ISSN 1873-3441, Vol. 134, s. 60-67Artikel i tidskrift (Refereegranskat)
    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.

  • 47.
    Bradley, Siobhan J.
    et al.
    Victoria University of Wellington, New Zealand.
    Kroon, Renee
    Chalmers University of Technology, Sweden.
    Laufersky, Geoffry
    Victoria University of Wellington, New Zealand.
    Röding, Magnus
    RISE - Research Institutes of Sweden, Biovetenskap och material, Jordbruk och livsmedel.
    Goreham, Renee V.
    Victoria University of Wellington, New Zealand.
    Gschneidtner, Tina
    Chalmers University of Technology, Sweden.
    Schroeder, Kathryn
    Victoria University of Wellington, New Zealand.
    Moth-Poulsen, Kasper
    Chalmers University of Technology, Sweden.
    Andersson, Mats
    Chalmers University of Technology, Sweden ; University of South Australia, Australia.
    Nann, Thomas
    Victoria University of Wellington, New Zealand.
    Heterogeneity in the fluorescence of graphene and graphene oxide quantum dots2017Ingår i: Microchimica Acta, ISSN 0026-3672, E-ISSN 1436-5073, Vol. 184, nr 3, s. 871-878Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Heterogeneity is an inherent property of a wealth of real-world nanomaterials and yet rarely in the reporting of new properties is its effect sufficiently addressed. Graphene quantum dots (GQDs) – fluorescent, nanoscale fragments of graphene - are an extreme example of a heterogeneous nanomaterial. Here, top-down approaches – by far the most predominant – produce batches of particles with a distribution of sizes, shapes, extent of oxidation, chemical impurities and more. This makes characterization of these materials using bulk techniques particularly complex and comparisons of properties across different synthetic methods uninformative. In particular, it hinders the understanding of the structural origin of their fluorescence properties. We present a simple synthetic method, which produces graphene quantum dots with very low oxygen content that can be suspended in organic solvents, suggesting a very pristine material. We use this material to illustrate the limitations of interpreting complex data sets generated by heterogeneous materials and we highlight how misleading this “pristine” interpretation is by comparison with graphene oxide quantum dots synthesized using an established protocol. In addition, we report on the solvatochromic properties of these particles, discuss common characterization techniques and their limitations in attributing properties to heterogeneous materials.

  • 48.
    Brodin, Ida
    et al.
    RISE., Innventia.
    Ernstsson, Marie
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, YKI – Ytkemiska institutet.
    Gellerstedt, Göran
    RISE., Innventia.
    Sjöholm, Elisabeth
    RISE., Innventia.
    Oxidative stabilisation of kraft lignin for carbon fibre production2012Ingår i: Holzforschung, ISSN 0018-3830, E-ISSN 1437-434X, nr 2, s. 141-147Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    With the aim of investigating kraft lignin as a raw material for carbon fibre production, different lignins have been stabilised in air at conditions varied according to a full factorial experimental design. The lignins under examination were purified kraft lignin powders originating from birch, spruce/pine and Eucalyptus globules, as well as lignin fibres originating from birch with 5 poly(ethylene oxide) (PEO) added as a plasticiser. The influence of temperature, time and heating rate on yield and glass-transition temperature (Tg) was investigated. The highest yield was achieved after stabilisation at 280°C during 2h with a heating rate of 0.2°C min -1. The Tg of all lignin powders was increased when stabilisation occurred under harsher conditions. X-ray photoelectron spectroscopy analysis (XPS) of both the outer surface and the cleaved cross-section of individual lignin/PEO fibres showed a clear gradient in the degree of chemical modification, with the major change occurring on the surface resulting in the appearance of a skin-core structure after stabilisation. The behaviour of the lignin fibres during stabilisation is similar to that of pitch-based fibres, indicating good possibilities for lignin as raw material for carbon fibre production.

  • 49.
    Brooke, Robert
    et al.
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    Lay, M
    Linköping University, Sweden; Leibniz Institute for New Materials, Germany.
    Jain, K
    KTH Royal Institute of Technology, Sweden.
    Francon, H
    KTH Royal Institute of Technology, Sweden.
    Say, Mehmet
    Linköping University, Sweden.
    Belaineh Yilma, Dagmawi
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    Wang, Xin
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    Håkansson, Karl
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign.
    Wågberg, L
    KTH Royal Institute of Technology, Sweden.
    Engquist, I
    Linköping University, Sweden; .
    Edberg, Jesper
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    Berggren, M
    Linköping University, Sweden.
    Nanocellulose and PEDOT:PSS composites and their applications2023Ingår i: Polymer Reviews, ISSN 1558-3724, nr 2, s. 437-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The need for achieving sustainable technologies has encouraged research on renewable and biodegradable materials for novel products that are clean, green, and environmentally friendly. Nanocellulose (NC) has many attractive properties such as high mechanical strength and flexibility, large specific surface area, in addition to possessing good wet stability and resistance to tough chemical environments. NC has also been shown to easily integrate with other materials to form composites. By combining it with conductive and electroactive materials, many of the advantageous properties of NC can be transferred to the resulting composites. Conductive polymers, in particular poly(3,4-ethylenedioxythiophene:poly(styrene sulfonate) (PEDOT:PSS), have been successfully combined with cellulose derivatives where suspensions of NC particles and colloids of PEDOT:PSS are made to interact at a molecular level. Alternatively, different polymerization techniques have been used to coat the cellulose fibrils. When processed in liquid form, the resulting mixture can be used as a conductive ink. This review outlines the preparation of NC/PEDOT:PSS composites and their fabrication in the form of electronic nanopapers, filaments, and conductive aerogels. We also discuss the molecular interaction between NC and PEDOT:PSS and the factors that affect the bonding properties. Finally, we address their potential applications in energy storage and harvesting, sensors, actuators, and bioelectronics. © 2022 The Author(s). 

  • 50.
    Brooke, Robert
    et al.
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    Petsagkourakis, Ioannis
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    Majee, Subimal
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    Olsson, Oliver
    Chalmers University of Technology, Sweden.
    Dahlin, Aandres
    Chalmers University of Technology, Sweden.
    Andersson Ersman, Peter
    RISE Research Institutes of Sweden, Digitala system, Smart hårdvara.
    All-Printed Multilayers and Blends of Poly(dioxythiophene) Derivatives Patterned into Flexible Electrochromic Displays2023Ingår i: Macromolecular materials and engineering, ISSN 1438-7492, E-ISSN 1439-2054, Vol. 308, nr 2, artikel-id 2200453Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Low-cost, flexible and thin display technology is becoming an interesting field of research as it can accompany the wide range of sensors being developed. Here, the synthesis of poly(dimethylpropylene-dioxythiophene) (PProDOT-Me2) by combining vapor phase polymerization and screen printing is presented. A multilayer architecture using poly(3,4-ethylenedioxythiophene) (PEDOT) and PProDOT-Me2 to allow for electrochromic switching of PProDOT-Me2, thereby eliminating the need for a supporting transparent conductive (metal oxide) layer is introduced. Furthermore, the technology is adapted to a blended architecture, which removes the additional processing steps and results in improved color contrast (∆E* &gt; 25). This blend architecture is extended to other conductive polymers, such as PEDOT and polypyrrole (PPy), to highlight the ability of the technique to adjust the color of all-printed electrochromic displays. As a result, a green color is obtained when combining the blue and yellow states of PEDOT and PPy, respectively. This technology has the potential to pave the way for all-printed multicolored electrochromic displays for further utilization in printed electronic systems in various Internet of Things applications. © 2022 The Authors. 

1234567 1 - 50 av 397
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf