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  • 1.
    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 precursors2019Inngår i: Holzforschung, ISSN 0018-3830, E-ISSN 1437-434X, Vol. 73, nr 5, s. 509-516Artikkel i tidsskrift (Fagfellevurdert)
    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.

  • 2.
    Bengtsson, Jenny
    et al.
    RISE - Research Institutes of Sweden, Swerea, Swerea IVF AB.
    Jedvert, Kerstin
    RISE - Research Institutes of Sweden, Swerea, Swerea IVF AB.
    Köhnke, Tobias
    RISE - Research Institutes of Sweden, Swerea, Swerea IVF AB.
    Theliander, Hans
    Chalmers University of Technology, Sweden.
    Dry-jet wet-spun lignin-based carbon fibre precursors2018Konferansepaper (Annet vitenskapelig)
  • 3.
    Bengtsson, Jenny
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Material och produktion, IVF. Chalmers University of Technology, Sweden.
    Jedvert, Kerstin
    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.
    Identifying breach mechanism during air-gap spinning of lignin–cellulose ionic-liquid solutions2019Inngår i: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, artikkel-id 47800Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    To be able to produce highly oriented and strong fibers from polymer solutions, a high elongational rate during the fiber-forming process is necessary. In the air-gap spinning process, a high elongational rate is realized by employing a high draw ratio, the ratio between take-up and extrusion velocity. Air-gap spinning of lignin–cellulose ionic-liquid solutions renders fibers that are promising to use as carbon fiber precursors. To further improve their mechanical properties, the polymer orientation should be maximized. However, achieving high draw ratios is limited by spinning instabilities that occur at high elongational rates. The aim of this experimental study is to understand the link between solution properties and the critical draw ratio during air-gap spinning. A maximum critical draw ratio with respect to temperature is found. Two mechanisms that limit the critical draw ratio are proposed, cohesive breach and draw resonance, the latter identified from high-speed videos. The two mechanisms clearly correlate with different temperature regions. The results from this work are not only of value for future work within the studied system but also for the design of air-gap spinning processes in general.

    Fulltekst (pdf)
    fulltext
  • 4.
    Bengtsson, Jenny
    et al.
    RISE Research Institutes of Sweden, Material och produktion, Kemi, biomaterial och textil. Chalmers University of Technology, Sweden.
    Jedvert, Kerstin
    RISE Research Institutes of Sweden, Material och produktion, Kemi, biomaterial och textil.
    Köhnke, Tobias
    RISE Research Institutes of Sweden, Material och produktion, Kemi, biomaterial och textil.
    Theliander, Hans
    Chalmers University of Technology, Sweden.
    The challenge of predicting spinnability: Investigating benefits of adding lignin to cellulose solutions in air-gap spinning2021Inngår i: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 138, nr 26, artikkel-id 50629Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this study, the underlying mechanism for improved spinnability when mixing lignin and cellulose in solution was investigated. Co-processing of lignin and cellulose has previously been identified as a potential route for production of inexpensive and bio-based carbon fibers. The molecular order of cellulose contributes to the strength of the fibers and the high carbon content of lignin improves the yield during conversion to carbon fibers. The current work presents an additional benefit of combining lignin and cellulose; solutions that contain both lignin and cellulose could be air-gap spun at substantially higher draw ratios than pure cellulose solutions, that is, lignin improved the spinnability. Fibers were spun from solutions containing different ratios of lignin, from 0 to 70 wt%, and the critical draw ratio was determined at various temperatures of solution. The observations were followed by characterization of the solutions with shear and elongational viscosity and surface tension, but none of these methods could explain the beneficial effect of lignin on the spinnability. However, by measuring the take-up force it was found that lignin seems to stabilize against diameter fluctuations during spinning, and plausible explanations are discussed

  • 5.
    Bengtsson, Jenny
    et al.
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Jedvert, Kerstin
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Köhnke, Tobias
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Theliander, T
    Coagulation of dry-jet wet-spun lignin-based carbon fibre precursors2018Inngår i: Proceedings of the 15th European workshop on lignocellulosics and pulp, 2018, s. 123-126Konferansepaper (Fagfellevurdert)
  • 6.
    Bengtsson, Jenny
    et al.
    RISE Research Institutes of Sweden, Material och produktion, Polymer, fiber och komposit.
    Johnsson, Erica
    RISE Research Institutes of Sweden, Material och produktion, Polymer, fiber och komposit.
    Ulmefors, Hanna
    RISE Research Institutes of Sweden, Material och produktion, Polymer, fiber och komposit.
    Köhnke, Tobias
    RISE Research Institutes of Sweden, Material och produktion, Polymer, fiber och komposit.
    Maloney, Thaddeus
    Aalto University, Finland.
    Revealing pore size distribution in cellulose and lignin-cellulose man-made fibers – effect of draw ratio and lignin content2024Inngår i: Cellulose, ISSN 0969-0239, E-ISSN 1572-882XArtikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    There are limited methods available for measurement of the porosity of cellulose fibers, even more so for obtaining a pore size distribution. Conventional pore analysis methods require dry samples, with intact pores. However, pores in cellulose fibers collapse when dried from water and thus present a challenge for sample analysis. Furthermore, the pore collapse is partially irreversible which should be accounted for in the analysis. In this study, analysis of pore structure was carried out in the wet state with thermoporometry and also for critical point dried samples, analyzed with N2 sorption. This study determines the effect of fiber lignin content and certain spinning parameters on the pore size distribution of spun fibers before and after drying. It could also be concluded that solvent exchange, drying from a non-polar solvent will result in an altered pore size distribution, with a total pore volume greater than if dried from water, however not representative of the never-dried state. It is concluded that thermoporometry together with the water retention value (WRV) measurement is a powerful combination to acquire insights to the pore size distribution of spun fiber. 

    Fulltekst (pdf)
    fulltext
  • 7.
    Bengtsson, Jenny
    et al.
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Olsson, Carina
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Hedlund, Artur
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Köhnke, Tobias
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Bialik, Erik
    Molecules in Motion, Sweden.
    Understanding the Inhibiting Effect of Small-Molecule Hydrogen Bond Donors on the Solubility of Cellulose in Tetrabutylammonium Acetate/DMSO2017Inngår i: Journal of Physical Chemistry B, ISSN 1520-6106, E-ISSN 1520-5207, Vol. 121, nr 50, s. 11241-11248Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Certain ionic liquids are powerful cellulose solvents, but tend to be less effective when small-molecule hydrogen bond donors are present. This is generally attributed to competition with cellulose for hydrogen bonding opportunities to the anion of the ionic liquid. We show that the solubility of cellulose in dimethyl sulfoxide solutions of tetrabutylammonium acetate is less strongly affected by water than by ethanol on a molar basis, contrary to what can be expected based on hydrogen bond stoichiometry. Molecular dynamics simulations indicate that the higher tolerance to water is due to water-cellulose interactions that improves solvation of cellulose and, thereby, marginally favors dissolution. Through Kirkwood-Buff theory we show that water, but not ethanol, improves the solvent quality of DMSO and partly compensates for the loss of acetate-cellulose hydrogen bonds.

  • 8.
    Bengtsson, Jenny
    et al.
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Olsson, Carina
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Idström, Alexander
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Köhnke, Tobias
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Impact of non-solvents in the tetrabutylammonium acetate: dimethyl sulfoxide-cellulose system2016Inngår i: The 7th Workshop on cellulose, regenerated cellulose and cellulose derivatives, 2016, s. 19-22Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    This work examines the potential of tetrabutylammonium acetate: dimethyl sulfoxide (TBAAc:DMSO) as a solvent used in a process for producing man-made cellulose fibers. The tolerance towards nonsolvents is an important step to evaluate the recyclability of the solvent. TBAAc:DMSO was in this work further confirmed to be an efficient solvent for cellulose. Non-solvent tolerance depended on cellulose concentration, TBAAc:DMSO ratio and type of non-solvent. There was no significant change in mechanical properties for filaments regenerated from solutions containing 2 wt% non-solvent compared to those spun from virgin solvent. With 4 wt% ethanol present in solution very brittle filaments were produced, not suitable for use as textile fibers.

  • 9.
    Bengtsson, Jenny
    et al.
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Olsson, Carina
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Köhnke, Tobias
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Bialik, Erik
    Lund University, Sweden.
    Elucidating the effect of non-solvents on the TBAAc/DMSO-cellulosesolvent system2017Inngår i: Cellulosic material properties and industrial potential: Final meeting in COST FP1205, 2017Konferansepaper (Annet vitenskapelig)
  • 10.
    Dang, Binh T.
    et al.
    Chalmers University of Technology, Sweden.
    Brelid, Harald
    Södra Innovation, Sweden.
    Köhnke, Tobias
    RISE., Swerea, IVF.
    Theliander, Hans
    Chalmers University of Technology, Sweden.
    Effect of sodium ion concentration profile during softwood kraft pulping on delignification rate, xylan retention and reactions of hexenuronic acids2014Inngår i: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 29, nr 4, s. 604-611Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The objective of this investigation was to study how different concentration profiles of sodium ions influence the delignification rate, hexenuronic acid formation/degradation and xylan retention under kraft cooking conditions. The concentration of sodium ions was varied in time between 0.52 and 3.00 mol/kg solvent, taking two different routes by the controlled addition of sodium carbonate. The reaction rates of hexenuronic acid were found to increase when the sodium ion concentration was at the higher level. Furthermore, the results implied that the kinetics of hexenuronic acid reactions responds rapidly to changes in sodium ion concentration. Delignification and the removal rates of xylan decreased rapidly after the sodium ion concentration was increased. However, when the sodium ion concentration was decreased, the response to the change was delayed. These findings indicate that effects of ionic strength on the rate of delignification and removal of xylan arise as a consequence of changes in solubility and on mass transport phenomena rather than from the rates of chemical reaction. Furthermore, the results suggest that non-dissolved xylan located in the fibre wall matrix may also sorb on cellulose surfaces relatively early on in the cook if the concentration of sodium ions is at high level.

  • 11.
    Dang, Binh T.
    et al.
    Chalmers University of Technology, Sweden.
    Brelid, Harald
    Södra Innovation, Sweden.
    Köhnke, Tobias
    RISE., Swerea, IVF.
    Theliander, Hans
    Chalmers University of Technology, Sweden.
    Impact of ionic strength on delignification and hemicellulose removal during kraft cooking in a small-scale flow-through reactor2013Inngår i: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 28, nr 3Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The effect of ionic strength/sodium ion concentration and type of anions on the delignification rate, the retention of xylan and the reactions of hexenuronic acid during kraft cooking has been investigated. A novel, small, flow-through digester was used in the cooking experiments in order to prevent the resorption of lignin and xylan and to maintain a constant concentration of active chemicals throughout the kraft cook. An increase in ionic strength/sodium ion concentration in the cooking liquor decreases the removal rate of both lignin and xylan during kraft cooking. In general, the removal rate of xylan tends to correlate with the delignification rate. However, the present investigation finds that the retention of xylan at a given degree of delignification increases at high ionic strength/sodium ion concentration. The addition of sodium salts of carbonate or chloride to the cooking liquor was shown to increase the rate of formation/degradation reactions of hexenuronic acids and the total amount of uronic acids substituted on the xylan backbone decreases when the concentration of sodium ions increases in the cooking liquor. This promotes a decrease in the dissolution of xylan and consequently an increase in the retention of xylan in the wood residues. The obtained results demonstrate that the xylan content in the fiber wall increases at higher ionic strength/sodium ion concentration, which leads to a slight increase in pulp yield.

  • 12.
    Hedlund, Artur
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Material och produktion, IVF.
    Hagman, Joel
    RISE., Swerea.
    Köhnke, Tobias
    RISE - Research Institutes of Sweden (2017-2019), Material och produktion, IVF.
    Theliander, Hans
    RISE., Swerea. Chalmers University of Technology, Sweden.
    Hagström, Bengt
    RISE., Swerea.
    Cosolvent and non-solvent effects on EmimAc-cellulose solutions’ rheology investigated inoscillatory shear and elongation2016Inngår i: 6th Avancell conference, 2016Konferansepaper (Annet vitenskapelig)
  • 13.
    Hedlund, Artur
    et al.
    RISE - Research Institutes of Sweden, Material och produktion, IVF. Chalmers University of Technology, Sweden.
    Köhnke, Tobias
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Hagman, Joel
    Lund University, Sweden.
    Olsson, Ulf
    Lund University, Sweden.
    Theliander, Hans
    Chalmers University of Technology, Sweden; KTH Royal Institute of Technology, Sweden.
    Microstructures of cellulose coagulated in water and alcohols from 1-ethyl-3-methylimidazolium acetate: contrasting coagulation mechanisms2019Inngår i: Cellulose, ISSN 0969-0239, E-ISSN 1572-882X, Vol. 26, nr 3, s. 1545-1563Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Abstract: Coagulation of cellulose solutions is a process whereby many useful materials with variable microstructures and properties can be produced. This study investigates the complexity of the phase separation that generates the structural heterogeneity of such materials. The ionic liquid, 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]), and a co-solvent, dimethylsulfoxide (DMSO), are used to dissolve microcrystalline cellulose in concentrations from 5 to 25 wt%. The solutions are coagulated in water or 2-propanol (2PrOH). The coagulated material is then washed and solvent exchanged (water → 2PrOH → butanone → cyclohexane) in order to preserve the generated microstructures upon subsequent drying before analysis. Sweep electron microscopy images of 50 k magnification reveal open-pore fibrillar structures. The crystalline constituents of those fibrils are estimated using wide-angle X-ray spectroscopy and specific surface area data. It is found that the crystalline order or crystallite size is reduced by an increase in cellulose concentration, by the use of the co-solvent DMSO, or by the use of 2PrOH instead of water as the coagulant. Because previous theories cannot explain these trends, an alternative explanation is presented here focused on solid–liquid versus liquid–liquid phase separations. Graphical abstract: [Figure not available: see fulltext.].

  • 14.
    Hedlund, Artur
    et al.
    RISE., Swerea, IVF.
    Köhnke, Tobias
    RISE., Swerea, IVF.
    Theliander, H.
    Chalmers University of Engineering, Sweden.
    Coagulation of EmimAc-cellulose solutions: Dissolution-precipitation disparity and effects of non-solvents and cosolvent2015Inngår i: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 30, nr 1, s. 32-42Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Coagulation values (CVs) of cellulose/1-ethyl-3-methylimidazolium acetate (EmimAc)/dimethyl-sulfoxide (DMSO) solutions for water, ethanol (EtOH) and 2-propanol (2-PrOH) were measured by using a light-scattering technique. Expressed in moles per mole, CVs of H2O were roughly twice as high as the CVs of EtOH and 2-PrOH at equal cellulose concentration for EmimAc solutions without the addition of a cosolvent. We explain this observation mainly in terms of alcohol alkyl chains efficiently obstructing EmimAc anions, preventing anions from simultaneously interacting with cellulose hydroxyls. DMSO was found to mitigate the coagulating effect of water and, to a lesser extent, the effect of alcohols. The explanation may be the different enthalpies of mixing for water and alcohols, with DMSO. An explanation on a more practical level, is based on how the solvatochromic α and β parameters change due to small amounts of the different non-solvents. Small additions of methanol induce disproportionately large changes from basic towards acidic properties for DMSO, meanwhile, the same stoichiometric addition of water induces only minor changes. Precipitation occurred at concentrations of non-solvent much higher than the concentrations that limit dissolution. The most likely explanation for this is a metastable region in the phase diagram. It was also seen that the typically observed inhibitive effect of high Mw on solubility during dissolution did not apply to precipitation. 

  • 15.
    Hedlund, Artur
    et al.
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Köhnke, Tobias
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Theliander, Hans
    Chalmers University of Technology, Sweden.
    Coagulation of cellulose solutions and controlling properties of regenerated cellulose materials2017Inngår i: Cellulosic material Properties and industrial potential: Final meeting in COST FP1205 / [ed] Monica Ek, 2017, s. 64-66Konferansepaper (Fagfellevurdert)
  • 16.
    Hedlund, Artur
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Material och produktion, IVF. Chalmers University of Technology, Sweden.
    Köhnke, Tobias
    RISE., Swerea, IVF.
    Theliander, Hans
    Chalmers University of Technology, Sweden.
    Coagulation of cellulose-EmimAc-DMSO solutions studied in order to control properties of wet-spun cellulose fibers2016Inngår i: The 7th Workshop on cellulose, regenerated cellulose and cellulose derivatives, 2016, s. 49-52, artikkel-id 15Konferansepaper (Annet vitenskapelig)
  • 17.
    Hedlund, Artur
    et al.
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Köhnke, Tobias
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Theliander, Hans
    Chalmers.
    Coagulation Values of Cellulose-EmimAc-DMSO solutions and their precipitation-dissolution disparity2014Inngår i: Proceedings of the  4th Avancell conference: Creating Value from the Swedish Forest Resources, 2014, s. 15-21Konferansepaper (Annet vitenskapelig)
  • 18.
    Hedlund, Artur
    et al.
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Köhnke, Tobias
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Theliander, Hans
    RISE - Research Institutes of Sweden, Material och produktion, IVF. Chalmers University of Technology, Sweden.
    Diffusion in Ionic Liquid-Cellulose Solutions during Coagulation in Water: Mass Transport and Coagulation Rate Measurements2017Inngår i: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 50, nr 21, s. 8707-8719Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This article describes central features of the mass transport during the coagulation in water of cellulose-1-ethyl-3-methylimidazoium acetate ([C2mim][OAc]) solutions, namely, that the diffusivities are mainly affected by the relative concentrations of water and [C2mim][OAc], that the concentration of cellulose does not affect diffusivities and coagulation rates, that the diffusivities of low-Mw compounds are similar to those in aqueous [C2mim][OAc] solutions without macromolecules, that the polymer concentration is diluted by the large influx of coagulant causing a positive net mass gain, NMG, from diffusive fluxes, and that such NMG, although observed only as a function in time, is also a function in space that has local peaks significantly higher than the mean NMG value. The conclusion from the first three findings was that the diffusion advances through a liquid phase which possesses a continuous pore network and most of the volume. The precipitated cellulose is concentrated into fibrils whose inhibitive effect on the diffusion of small molecules through the surrounding phase is marginal. This key understanding about mass transport during coagulation also simplifies numerical modeling significantly.

  • 19.
    Hedlund, Artur
    et al.
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Köhnke, Tobias
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Theliander, Hans
    Chalmers University.
    Measurements of mass transport during coagulation of cellulose-EmimAc-DMSO solutions2015Inngår i: Proceedings of the 4th EPNOE international Polysaccharide Conference, 2015Konferansepaper (Annet vitenskapelig)
  • 20.
    Hedlund, Artur
    et al.
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Köhnke, Tobias
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Theliander, Hans
    Chalmers University of Technology, Sweden.
    Structure of cellulosematerials coagulated from different EmimAc-DMSO solutions2015Konferansepaper (Annet vitenskapelig)
  • 21.
    Hedlund, Artur
    et al.
    RISE - Research Institutes of Sweden, Material och produktion, IVF. Chalmers University of Technology, Sweden.
    Theliander, Hans
    Chalmers University of Technology, Sweden.
    Köhnke, Tobias
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Mass transport during coagulation of cellulose-ionic liquid solutions in different non-solvents2019Inngår i: Cellulose, ISSN 0969-0239, E-ISSN 1572-882X, Vol. 26, nr 16, s. 8525-8541Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Abstract: Cellulose can be regenerated from cellulose-ionic liquid (IL) solutions by immersion in water or alcohols. These compounds are potent non-solvents due to their proton-donating ability in hydrogen bonds to IL anions. Although they share this fundamental way of reducing IL solvent quality, coagulation in water is distinctly different from coagulation in alcohols with regard to the microstructures formed and the mechanisms that generate the microstructures. In this study, the possibility of mass-transport effects on microstructures was investigated. The mass-transport of all components: non-solvent (EtOH, 2PrOH), IL ([C2mim][OAc]), and a co-solvent (DMSO), during coagulation was studied. The data was compared to previous data with water as the non-solvent. Results showed that diffusion is essentially limited to a continuous non-solvent-rich phase that is formed during phase separation in all non-solvents. There were also significant differences between non-solvents. For instance, [C2mim][OAc] diffusion coefficients were 6–9 times smaller in 2PrOH than in water, and there were apparent effects from cellulose concentration in 2PrOH that were not observed in water. The differences stem from the interactions between solvent, non-solvents, and cellulose, which can be both mutual and competitive. Weaker [C2mim][OAc]-non-solvent interactions with alcohols give more persistent [C2mim][OAc]-cellulose interactions than with water as the non-solvent, which has consequences for mass-transport. Graphic abstract: [Figure not available: see fulltext.].

  • 22.
    Idström, Alexander
    et al.
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Gentile, Luigi
    Lund University, Sweden.
    Gubitosi, Marta
    Lund University, Sweden.
    Olsson, Carina
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Stenqvist, Björn
    Lund University, Sweden.
    Lund, Mikael
    Lund University, Sweden.
    Bergquist, Karl Erik
    Lund University, Sweden.
    Olsson, Ulf
    Lund University, Sweden.
    Köhnke, Tobias
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Wernersson, E
    Tetrabutylammonium acetate/dimethyl sulfoxide  as a solvent for cellulose2017Konferansepaper (Annet vitenskapelig)
  • 23.
    Idström, Alexander
    et al.
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Gentile, Luigi
    Lund University, Sweden.
    Gubitosi, Marta
    Lund University, Sweden.
    Olsson, Carina
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Stenqvist, Björn
    Lund University, Sweden.
    Lund, Mikael
    Lund University, Sweden.
    Bergquist, Karl Erik
    Lund University, Sweden.
    Olsson, Ulf
    Lund University, Sweden.
    Köhnke, Tobias
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Wernersson, E.
    Tetrabutylammonium acetate/dimethyl sulfoxide  as a solvent for cellulose2016Konferansepaper (Annet vitenskapelig)
  • 24.
    Idström, Alexander
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Material och produktion, IVF.
    Gentile, Luigi
    Lund University, Sweden.
    Gubitosi, Marta
    Lund University, Sweden.
    Olsson, Carina
    RISE - Research Institutes of Sweden (2017-2019), Material och produktion, IVF.
    Stenqvist, Björn
    Lund University, Sweden.
    Lund, Mikael
    Lund University, Sweden.
    Bergquist, Karl Erik
    Lund University, Sweden.
    Olsson, Ulf
    Lund University, Sweden.
    Köhnke, Tobias
    RISE., Swerea, IVF.
    Wernersson, Erik
    Lund University, Sweden.
    Dissolution of cellulose in tetrabutylammonium acetate/dimethyl sulfoxide2016Inngår i: The 7th Workshop on cellulose, regenerated cellulose and cellulose derivatives, 2016, s. 15-18, artikkel-id 1Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    The dissolution of cellulose in tetrabutylammonium acetate (TBAAc)/dimethyl sulfoxide (DMSO) was studied combining experimental and simulation techniques. It was found that the dissolution limit at 40 °C corresponded to a molar ratio close to one acetate per cellulose anhydroglucose units. MD simulations suggested that the acetate ions bind to cellulose by dual hydrogen bonds. This effectively turns cellulose into a polyelectrolyte, attracting the bulky tetrabutylammonium (TBA+ ) counter ions, which prevent close contact between chains in the dissolved state. This hypothesis was tested by 1 Hand 13C-NMR spectroscopy, which confirmed that acetate forms hydrogen bonds to cellulose, and by diffusion NMR spectroscopy, which demonstrated a strong dynamic correlation between bound acetate and tetrabutylammonium in near-quantitative agreement with simulation. The present results suggest that offering hydrogen bonding to the acetate ions is the main driving force for dissolving cellulose and that the TBA+ counter ions form a diffuse layer around the acetate-decorated cellulose chains.

  • 25.
    Idström, Alexander
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Material och produktion, IVF.
    Gentile, Luigi
    Lund University, Sweden.
    Gubitosi, Marta
    Lund University, Sweden.
    Olsson, Carina
    RISE - Research Institutes of Sweden (2017-2019), Material och produktion, IVF.
    Stenqvist, Björn
    Lund University, Sweden.
    Lund, Mikael
    Lund University, Sweden.
    Bergquist, Karl-Erik
    Lund University, Sweden.
    Olsson, Ulf
    Lund University, Sweden.
    Köhnke, Tobias
    RISE - Research Institutes of Sweden (2017-2019), Material och produktion, IVF.
    Bialik, Erik
    Lund University, Sweden.
    On the dissolution of cellulose in tetrabutylammonium acetate/dimethyl sulfoxide: a frustrated solvent2017Inngår i: Cellulose, ISSN 0969-0239, E-ISSN 1572-882X, Vol. 24, nr 9, s. 3645-3657Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We have found that the dissolution of cellulose in the binary mixed solvent tetrabutylammonium acetate/dimethyl sulfoxide follows a previously overlooked near-stoichiometric relationship such that one dissolved acetate ion is able to dissolve an amount of cellulose corresponding to about one glucose residue. The structure and dynamics of the resulting cellulose solutions were investigated using small-angle X-ray scattering (SAXS) and nuclear magnetic resonance techniques as well as molecular dynamics simulation. This yielded a detailed picture of the dissolution mechanism in which acetate ions form hydrogen bonds to cellulose and causes a diffuse solvation sheath of bulky tetrabutylammonium counterions to form. In turn, this leads to a steric repulsion that helps to keep the cellulose chains apart. Structural similarities to previously investigated cellulose solutions in aqueous tetrabutylammonium hydroxide were revealed by SAXS measurement. To what extent this corresponds to similarities in dissolution mechanism is discussed.

  • 26.
    Jedvert, Kerstin
    et al.
    RISE Research Institutes of Sweden, Material och produktion, Kemi, biomaterial och textil.
    Idström, Alexander
    RISE Research Institutes of Sweden, Material och produktion.
    Köhnke, Tobias
    Alkhagen, Mårten
    RISE Research Institutes of Sweden, Material och produktion, Kemi, biomaterial och textil.
    Cellulosic nonwovens produced via efficient solution blowing technique2020Inngår i: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 137, nr 5, artikkel-id 48339Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The demand for nonwoven materials has increased during the last few years and is expected to increase further due to its use in a broad range of new application areas. Today, the majority of nonwovens are from petroleum-based resources but there is a desideratum to develop sustainable and competitive materials from renewable feedstock. In this work, renewable nonwovens are produced by solution blowing of dissolved cellulose using 1-ethyl-3-methylimidazolium acetate (EMIMAc) as solvent. Properties of cellulose solutions and process parameters, such as temperature, flow rate, air pressure, and distance to collector, are evaluated in respect to spinnability and material structural properties. Nonwovens with fiber diameters mainly in the micrometer range were successfully produced and it was shown that high temperature or low flow rate resulted in thinner fibers. The produced materials were stiffer (higher effective stress and lower strain) compared to commercial polypropylene nonwoven. © 2019 The Authors. Journal of Applied Polymer Science published by Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48339. © 2019 The Authors.

  • 27.
    Jedvert, Kerstin
    et al.
    RISE Research Institutes of Sweden, Material och produktion, Kemi, biomaterial och textil.
    Viklund, Linnea
    RISE Research Institutes of Sweden. Chalmers University of Technology, Sweden.
    Alkhagen, Mårten
    RISE Research Institutes of Sweden, Material och produktion, Kemi, biomaterial och textil.
    Köhnke, Tobias
    RISE Research Institutes of Sweden, Material och produktion, Kemi, biomaterial och textil.
    Theliander, Hans
    Chalmers University of Technology, Sweden.
    Tailoring the physical characteristics of solution blown cellulosic nonwovens by various post-treatments2021Inngår i: Nordic Pulp & Paper Research Journal, Vol. 36, nr 4, s. 682-695Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Nonwovens are increasing in demand due to their versatility which enables use in a broad range of applications. Most nonwovens are still produced from fossil-based resources and there is thus a need to develop competitive materials from renewable feedstock. In this work, nonwovens are produced from cellulose via a direct solution blowing method. 

  • 28.
    Jönsson, Christin
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Material och produktion, IVF, Energi och miljö.
    Posner, Stefan
    RISE - Research Institutes of Sweden (2017-2019), Material och produktion, IVF, Energi och miljö.
    Olsson, Carina
    RISE - Research Institutes of Sweden (2017-2019), Material och produktion, IVF.
    Köhnke, Tobias
    RISE - Research Institutes of Sweden (2017-2019), Material och produktion, IVF.
    Kristinsdottir, Anna Runa
    RISE - Research Institutes of Sweden (2017-2019), Material och produktion, IVF.
    Strååt, Martin
    RISE - Research Institutes of Sweden (2017-2019), Material och produktion, IVF.
    Schwarz, Lisa
    RISE - Research Institutes of Sweden (2017-2019), Material och produktion, IVF.
    Guo, Zengwei
    RISE - Research Institutes of Sweden (2017-2019), Material och produktion, IVF.
    Återvinning av textilier: Hur säkerställer man giftfria flöden i relation till textilåtervinning2016Rapport (Annet vitenskapelig)
    Abstract [sv]

    Huvudsyftet med arbetet var att främja ökad återvinning av textilt spill utan ökad spridning av giftiga ämnen eller minskad kvalitet. Arbetet har till stor del utförts genom fallstudier men även genom myndighetsdialoger, underlag till myndigheter och företag samt initiering av nya relevanta forskningsstudier.Målet i arbetspaket 3 Textil var att ta fram ett kvalificerat underlag för ökad användning av giftfri återvunnen textilråvara genom att studera och beskriva kunskapsläget samt ta fram ny kunskap och driva en aktiv dialog med relevanta aktörer inom fyra fokusområden:1. Spårbarhet2. Minskning av spill3. Teknikutveckling för återvinning av textil4. Återvinning på den svenska marknadenMålet har väl uppfyllts och projektet har bidragit till ökad kunskap om möjligheter för ökad användning av giftfri återvunnen textilråvara. Framförallt har fallstudier genererat detaljerad förståelse för vilka specifika utmaningar som är kopplade till olika textila material och fiberslag.Arbetet har utförts i tät samverkan och dialog med parter från textilbranchen: Boob, Filippa K, Gudrun Sjöden, Fjällräven och WRSD, Swegmarks, Ragnsells, Re:Newcell, samt några av deras leverantörer och flera medlemmar i Kemikaliegruppen på Swerea IVF.Projektet visar att materialspecifik kunskap och teknik är det viktigaste steget mot ökad återvinning av industriella restprodukter. Detta är således en förutsättning för att den sekundära råvaran ska ha ett tillräckligt värde och ändamålsenlig kvalitet. Dessa specifika aspekter kommer att studeras vidare inom efterföljand

    Fulltekst (pdf)
    Swerea IVF-rapport 17001 Återvinning av textilier
  • 29.
    Köhnke, Tobias
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Textile recycling at Swerea IVF, Cradle to Cradle Product Symposium & Innovation Celebration2015Konferansepaper (Annet vitenskapelig)
  • 30.
    Köhnke, Tobias
    et al.
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Theliander, Hans
    Chalmers University of Technology, Sweden.
    Hedlund, Artur
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Coagulation and structure formation of cellulose from EmimAc- DMSO solutions2015Konferansepaper (Annet vitenskapelig)
  • 31. Köhnke, Tobias
    et al.
    Theliander, Hans
    Chalmers University of Technology, Sweden.
    Hedlund, Artur
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Investigations into the coagulation of cellulose from EmimAc: DMSO solutions in common protic solvents2015Konferansepaper (Annet vitenskapelig)
  • 32.
    Martin-Bertelsen, Birte
    et al.
    Lund University, Sweden.
    Andersson, Erika
    Lund University, Sweden.
    Köhnke, Tobias
    RISE Research Institutes of Sweden, Material och produktion, Kemi, biomaterial och textil.
    Hedlund, Artur
    RISE Research Institutes of Sweden, Material och produktion, Kemi, biomaterial och textil.
    Stigsson, Lars
    KIRAM AB, Sweden.
    Olsson, Ulf
    Lund University, Sweden.
    Revisiting the dissolution of cellulose in NaOH as "Seen" by X-rays2020Inngår i: Polymers, E-ISSN 2073-4360, Vol. 12, nr 2, artikkel-id 342Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Cotton production is reaching a global limit, leading to a growing demand for bio-based textile fibers produced by other means. Textile fibers based on regenerated cellulose from wood holds great potential, but in order to produce fibers, the components need to be dissolved in suitable solvents. Furthermore, the dissolution process of cellulose is not yet fully understood. In this study, we investigated the dissolution state of microcrystalline cellulose in aqueous NaOH by using primarily scattering methods. Contrary to previous findings, this study indicated that cellulose concentrations of up to 2 wt % are completely molecularly dissolved in 8 wt % NaOH. Scattering data furthermore revealed the presence of semi-flexible cylinders with stiff segments. In order to improve the dissolution capability of NaOH, the effects of different additives have been of interest. In this study, scattering data indicated that the addition of ZnO decreased the formation of aggregates, while the addition of PEG did not improve the dissolution properties significantly, although preliminary NMR data did suggest a weak attraction between PEG and cellulose. Overall, this study sheds further light on the dissolution of cellulose in NaOH and highlights the use of scattering methods to assess solvent quality. © 2020 by the authors.

  • 33.
    Määttänen, Marjo
    et al.
    VTT Technical Research Centre of Finland, Finland.
    Gunnarsson, Maria
    RISE Research Institutes of Sweden, Bioekonomi och hälsa.
    Wedin, Helena
    RISE Research Institutes of Sweden, Bioekonomi och hälsa.
    Stibing, Sara
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign.
    Olsson, Carina
    RISE Research Institutes of Sweden.
    Köhnke, Tobias
    RISE Research Institutes of Sweden, Material och produktion, Kemi, biomaterial och textil.
    Asikainen, Sari
    VTT Technical Research Centre of Finland, Finland; Fortum Power and Heat Oy, Finland.
    Vehviläinen, Marianna
    VTT Technical Research Centre of Finland, Finland.
    Harlin, Ali
    VTT Technical Research Centre of Finland, Finland.
    Pre-treatments of pre-consumer cotton-based textile waste for production of textile fibres in the cold NaOH(aq) and cellulose carbamate processes2021Inngår i: Cellulose, ISSN 0969-0239, E-ISSN 1572-882X, Vol. 28, s. 3869-3886Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Recycling of textiles is of importance due to the large amount of waste generated from  the increasing consumption and use worldwide. Cotton-rich pre-consumer textiles are  considered as potential raw material for production of man-made regenerated fibres, but demands purification from the blends with synthetic fibres as well as the dyes and  finishing chemicals. In this study we explore the use of different pre-treatments of pre-consumer textiles to meet specific parameters for production of fibres in the cold  NaOH(aq) or cellulose carbamate process. The pre-treatments consisted of different  bleaching sequences and were performed on both uncoloured and coloured pre-consumer textiles. For the uncoloured textile, degree of polymerisation and amount of  inorganic content was efficiently reduced making the material suitable for both the cold  NaOH(aq) and the cellulose carbamate process. In case of the coloured textile, the pre-treatments were able to remove the dye and decrease the inorganic content as well as  reduce the degree of polymerisation but only sufficiently enough for production of fibres  in the cellulose carbamate process. The work was able to prove a fibre-to-fibre concept  while further optimisation of the regeneration steps is expected to improve the  mechanical properties of the produced fibres in future studies.

  • 34.
    Nechyporchuk, Oleksandr
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Material och produktion, IVF.
    Bordes, Romain
    Chalmers University of Technology, Sweden.
    Köhnke, Tobias
    RISE - Research Institutes of Sweden (2017-2019), Material och produktion, IVF.
    Wet Spinning of Flame-Retardant Cellulosic Fibers Supported by Interfacial Complexation of Cellulose Nanofibrils with Silica Nanoparticles2017Inngår i: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 9, nr 44, s. 39069-39077Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The inherent flammability of cellulosic fibers limits their use in some advanced applications. This work demonstrates for the first time the production of flame-retardant macroscopic fibers from wood-derived cellulose nanofibrils (CNF) and silica nanoparticles (SNP). The fibers are made by extrusion of aqueous suspensions of anionic CNF into a coagulation bath of cationic SNP at an acidic pH. As a result, the fibers with a CNF core and a SNP thin shell are produced through interfacial complexation. Silica-modified nanocellulose fibers with a diameter of ca. 15 μm, a titer of ca. 3 dtex and a tenacity of ca. 13 cN tex–1 are shown. The flame retardancy of the fibers is demonstrated, which is attributed to the capacity of SNP to promote char forming and heat insulation on the fiber surface.

  • 35.
    Nechyporchuk, Oleksandr
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Material och produktion, IVF.
    Håkansson, Karl
    RISE - Research Institutes of Sweden (2017-2019), Bioekonomi, Bioraffinaderi och energi.
    Gowda.V, Krishne
    KTH Royal Institute of Technology, Sweden.
    Lundell, Fredrik
    KTH Royal Institute of Technology, Sweden.
    Hagström, Bengt
    RISE - Research Institutes of Sweden (2017-2019), Material och produktion, IVF.
    Köhnke, Tobias
    RISE - Research Institutes of Sweden (2017-2019), Material och produktion, IVF.
    Continuous Assembly of Cellulose Nanofibrils and Nanocrystals into Strong Macrofibers through Microfluidic Spinning2018Inngår i: Advanced Materials Technologies, E-ISSN 2365-709X, artikkel-id 1800557Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Microfluidic fiber spinning is a promising technique for assembling cellulose nanomaterials into macroscopic fibers. However, its implementation requires upscalabe fabrication processes while maintaining high strength of the fibers, which could not be previously achieved. Herein, a continuous wet spinning process based on microfluidic flow focusing is developed to produce strong fibers from cellulose nanofibrils (CNFs) and nanocrystals (CNCs). Fibers with an average breaking tenacity as high as 29.5 cN tex−1 and Young's modulus of 1146 cN tex−1 are reported for the first time, produced from nonhighly purified CNF grades. Using the same developed method, wet spinning of fibers from CNCs is achieved for the first time, reaching an average Young's modulus of 1263 cN tex−1 and a breaking tenacity of 10.6 cN tex−1, thus exhibiting strength twice as high as that of common CNC films. A rather similar stiffness of CNC and CNF spun fibers may originate from similar degrees of alignment, as confirmed by wide-angle X-ray scattering (WAXS) and birefringence measurements, whereas lower strength may primarily arise from the shorter length of CNCs compared to that of CNFs. The benefit of CNCs is their higher solids content in the dopes. By combining both CNCs and CNFs, the fiber properties can be tuned.

  • 36.
    Nechyporchuk, Oleksandr
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Material och produktion, IVF.
    Köhnke, Tobias
    RISE - Research Institutes of Sweden (2017-2019), Material och produktion, IVF.
    Regenerated Casein-Nanocellulose Composite Fibers via Wet Spinning2019Inngår i: ACS Sustainable Chemistry and Engineering, E-ISSN 2168-0485, Vol. 7, nr 1, s. 1419-1426Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Development of sustainable biobased fibers is required to displace their fossil-based counterparts, e.g., in textile, nonwoven, or composite applications. Regenerated protein fibers have a potential in this regard if their mechanical properties are improved. Herein, we study for the first time the use of nanocellulose as reinforcement in regenerated protein fibers produced using wet spinning. The influence of cellulose nanocrystals (CNC) incorporated into regenerated casein fibers is examined in terms of mechanical and morphological properties. The influence of different conditions for fiber chemical cross-linking is also investigated. Incorporation of CNC (up to 37.5 wt %) into spin dopes results in a continuous increase of fiber Young's modulus (up to twofold) in the dry state. Both maximum and breaking tenacity of dry fibers are enhanced by CNC, with a maximum at 7.0-10.5 wt % of CNC. When testing after being wetted, both breaking tenacity and Young's modulus of the composite fibers decrease, likely due to weakening of hydrogen bonds between CNC in the presence of water. We also demonstrate that the presence of salt during chemical cross-linking is crucial to produce intact and separated fibers in the yarn.

  • 37.
    Nechyporchuk, Oleksandr
    et al.
    RISE Research Institutes of Sweden, Material och produktion, Kemi, biomaterial och textil.
    Yang Nilsson, Ting
    RISE Research Institutes of Sweden, Material och produktion, Kemi, biomaterial och textil.
    Hanna, Ulmefors
    RISE Research Institutes of Sweden, Material och produktion, Kemi, biomaterial och textil.
    Köhnke, Tobias
    RISE Research Institutes of Sweden, Material och produktion, Kemi, biomaterial och textil.
    Wet Spinning of Chitosan Fibers: Effect of Sodium Dodecyl Sulfate Adsorption and Enhanced Dope Temperature2020Inngår i: ACS Appl. Polym. Mater., ISSN 2637-6105, Vol. 2, nr 9, s. 3867-3875Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Production of fibers from non-thermoplastic polymers, such as chitosan, usually requires dissolution with subsequent fiber formation, for instance via coagulation. Good fiber-forming properties enable simultaneous spinning of multiple fibers into a yarn, which is one of the prerequisites for process scalability. Here, we report a multifilament wet spinning process that eliminates the use of such volatile organic compounds as methanol and acetone, enhances fiber formation and allows producing continuous well separated chitosan fibers after drying. This is achieved by: (i) solidification of the extruded solution by alkali and sodium acetate in the coagulation bath and (ii) further stabilization of the fibers by adsorbing the anionic surfactant, sodium dodecyl sulfate. The obtained fibers have circular cross-section and smooth surface. We demonstrate that it is possible to increase fiber breaking tenacity and Young′s modulus by applying stretching (draw ratios up to 1.77) or by incorporating cellulose nanofibrils (CNF, up to 4 wt% based on chitosan) in the spinning solutions However, the limitation of increased viscosity when adding CNF is needed to be overcome for possible higher reinforcement effects. We demonstrate that fiber breaking tenacity, Young′s modulus and elongation at break can be enhanced even further by increasing the spin dope temperature from 22 °C to 60 °C, simultaneously with increasing the spin dope solids content to keep the same dope viscosity. The fibers with maximum breaking tenacity of ca. 10 cN tex-1 at an elongation at break of ca. 7.5% were obtained.

  • 38.
    Olsson, Carina
    et al.
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Idström, Anna
    University of Helsinki, Finland.
    Bengtsson, Jenny
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Köhnke, Tobias
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Coagulation of cellulose solutions and its effect on material properties2016Inngår i: Proceedings of the 14th European workshop on lignocellulosics and pulp, 2016Konferansepaper (Annet vitenskapelig)
  • 39.
    Olsson, Carina
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Material och produktion, IVF.
    Köhnke, Tobias
    RISE - Research Institutes of Sweden (2017-2019), Material och produktion, IVF.
    Idström, Alexander
    RISE., Swerea, IVF. Chalmers University of Technology, Sweden.
    Gentile, Luigi
    Lund University, Sweden.
    Gubitosi, Marta
    Lund University, Sweden.
    Stenqvist, Björn
    Lund University, Sweden.
    Lund, Mikael
    Lund University, Sweden.
    Bergquist, Karl-Erik
    Lund University, Sweden.
    Olsson, Urban
    Lund University, Sweden.
    Wernersson, E.
    Tetrabutylammonium acetate as a solvent for cellulose2016Konferansepaper (Annet vitenskapelig)
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