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  • 1.
    Aminzadeh, Selda
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Lauberts, M.
    Dobele, G.
    Ponomarenko, J.
    Mattsson, T.
    Lindström, Mikael
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Sevastyanova, Olena
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Membrane filtration of kraft lignin: Structural charactristics and antioxidant activity of the low-molecular-weight fraction2018Inngår i: Industrial crops and products (Print), ISSN 0926-6690, E-ISSN 1872-633X, Vol. 112, s. 200-209Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Lignin, which is the second most abundant biomass component and has carbon-rich phenolic content, is a promising renewable raw material for multiple applications, such as carbon fibers, adhesives, and emulsifiers. To use lignin efficiently, it is important to ensure its purity and homogeneity. As a result, the separation of lignin into fractions with high purity and narrow molecular-weight distributions is likely a prerequisite for several applications. Ultrafiltration using ceramic membranes has many advantages, including enabling direct lignin extraction from Kraft pulp cooking liquors without pH and temperature adjustment. One challenge with membrane filtration using such a system is the potential for reduced membrane performance over time, which is associated with fouling. In this study, LignoBoost Kraft lignin was fractionated using a ceramic membrane with a molecular weight cut-off of 1 kDa. The separation behavior during ultrafiltration fractionation was investigated and the antioxidant properties of the recovered low-molecular-weight (low-MW) lignin samples were evaluated. Using this model system, the permeate fluxes were unstable during the 100 h of membrane operation. However, a decrease in the average MW in the permeate over time was observed. The shift in MW was most pronounced for virgin membranes, while a more stable MW distribution was evident for membranes subjected to multiple cleaning cycles. According to 2D NMR analysis, low-MW lignin that was recovered after 100 h of operation, consisted of smaller lignin fragments, such as dimers and oligomers, with a high content of methoxy-groups. This was confirmed using the size exclusion chromatography method, which indicated an weigh average molecular weight in the range of 450–500 Da. 31P NMR spectroscopy showed that, despite the lower total content of phenolic OH groups, the low-MW sample had a higher proportion of non-condensed phenolic OH groups. The results of the antioxidant tests demonstrated the strong potential of lignin and its low-MW fraction as a natural antioxidant, particularly for lipid-containing systems. The low-MW lignin fraction showed better antioxidant activity than the non-fractionated LignoBoost lignin in the kinetic oxygen radical absorbance capacity (ORAC) test and demonstrated three-fold stronger inhibition of the substrate (fluorescein) than the reference antioxidant Trolox (a water-soluble derivative of vitamin E).

  • 2.
    Aminzadeh, Selda
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Mattsson, Tuve
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Henriksson, Gunnar
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Lindström, Mikael
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    On the crossflow membrane fractionation of lignoboost kraft lignin: Characterization of low molecular weight fractions2016Inngår i: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 251Artikkel i tidsskrift (Annet vitenskapelig)
  • 3. Andersson, Alexander
    et al.
    Vegunta, Vijaya
    Lindström, Mikael
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Sevastyanova, Olena
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Träkemi och massateknologi.
    Jansson, Ulla
    Henriksson, Gunnar
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Träkemi och massateknologi.
    Presence of Calcium Cations Stimulate Alkaline Hydrolysis of Cellulose During Kraft Pulping ConditionsManuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    Simulated kraft pulping has been performed on cotton linters fibers consisting of almost pure cellulose with varying content of calcium ions. These concentrations were obtained by soaking and drying cotton linters in calcium sulfate solutions. The viscosities of the pulped fibers were generally lower with higher calcium ion concentration and, therefore, in line with earlier suggested ideas that calcium ions could catalyze alkaline hydrolysis. The technical importance of these results is discussed.

  • 4. Antonsson, S.
    et al.
    Lindström, Mikael
    KTH, Tidigare Institutioner (före 2005), Fiber- och polymerteknologi.
    Hogskolan, K. T.
    Ragnar, M.
    A comparative study of the impact of the cooking process on oxygen delignification2003Inngår i: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 18, nr 4, s. 388-394Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The impact of oxygen delignification on chemical pulps of a given kappa number manufactured in different ways (using kraft, prehydrolysis kraft and magnesium sulphite cooking) has been investigated. The prehistory of the pulps proves to be a very important factor in determining the response to oxygen delignification, i.e. the degree of delignification. It is shown that this is not due to different amounts of hexenuronic acid (HexA) in the different pulps, although this is an important factor behind the high residual kappa number after oxygen delignification of birch kraft pulp. Oxygen delignification of sulphite pulps proves to be efficient even at kappa numbers significantly lower than 10. These pulps show the greatest yield loss over the oxygen delignification. It is likely that Lignin Carbohydrate Complexes (LCC) complexes play a very important role in limiting the speed of reaction of oxygen delignification. Due to the very different prehistories of the pulps investigated, it is probable that the LCC:s are native and not formed during cooking.

  • 5.
    Antonsson, Stefan
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Henriksson, Gunnar
    KTH, Skolan för kemivetenskap (CHE).
    Johansson, Mats
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Lindström, Mikael
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Biomimetic synthesis of suberin for new biomaterials2005Inngår i: Appita Annual Conference: Vol 2, 2005, s. 561-564Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Suberin is the biopolymer giving cork (oak bark) its hydrophobic and resistant characteristics. It acts as a diffusion barrier in bark and roots of plants. Similarly to lignin, it is a phenolic polymer with good affinity to cellulose and other wood polysaccharides, but it also contains polyaliphatic and strongly hydrophobic elements. In order to produce a lignin derivative similar to suberin, a desired lignin starting material should be of low molecular weight and have a high content of hydroxylic phenolic groups. By means of cross flow nanofiltration of softwood kraft pulping black liquor and pH-precipitation with diluted sulphuric acid, such a lignin has been obtained. Due to the fact that too much organics entering the recovery boiler frequently is the bottleneck for pulp production increases, a removal of part of the lignin can be economically very favourable. By using this lignin together with linola oil, a linseed oil with a large amount of unsaturated structures, an attempt was made to create a new hydrophobic lignin derivative similar tosuberin. The product was analysed with FT-IR, Fourier Transformed Infra Red Spectroscopy and GPC, Gel Permeation Chromatography. The suberin like material obtained from this lignin could be polymerised on thermo mechanical pulp fibres by means of Mn(III)-driven phenolic coupling. The ability of the suberin monomers to act as a hydrophobic paper coating was evaluated with contact angle measurements and the results indicate that this lignin derivative was potentially of interest due to its capability to interact well with wood fibres and make paper hydrophobic.

  • 6.
    Antonsson, Stefan
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Henriksson, Gunnar
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Johansson, Mats
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Lindström, Mikael E.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Low Mw-lignin fractions together with vegetable oils as available oligomers for novel paper-coating applications as hydrophobic barrier2008Inngår i: Industrial crops and products (Print), ISSN 0926-6690, E-ISSN 1872-633X, Vol. 27, nr 1, s. 98-103Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Lignin residues are available in large amounts as kraft lignin from chemical pulping processes. This lignin is mainly incinerated in recovery boilers. The recovery boilers are often the bottle-necks in the overall pulping process when pulp production increases are desired. Through cross-flow nano-filtration of the black liquor from kraft pulping, a low-molecular weight lignin fraction can be removed thus decreasing the organic load on the recovery boilers. The low-molecular weight lignin fraction furthermore exhibit different characteristics compared to other commercial kraft lignins and represents a new raw material source in novel applications.

    The low-molecular weight lignin was used together with a vegetable oil to produce a new hydrophobic lignin derivative similar to suberin. The lignin and the lignin derivative was analysed with FT-IR, UV-vis and SEC. The ability of the product to make paper surfaces hydrophobic was also evaluated.

    The results demonstrate the possibility to make a suberin-like lignin derivative that is potentially of interest in paper-coating applications due to its capability to interact well with wood fibres and make paper hydrophobic.

  • 7.
    Antonsson, Stefan
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Henriksson, Gunnar
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Lindström, Mikael
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    The utilization of lignin derivatives and radical coupling reaction to increase wet strength of kraftliner2006Inngår i: 6th international paper and coating chemistry symposium. Book of abstracts., 2006, s. 55-55Konferansepaper (Fagfellevurdert)
  • 8.
    Antonsson, Stefan
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Henriksson, Gunnar
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Lindström, Mikael E.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Adding lignin derivatives to decrease the effect of mechano-sorptive creep in linerboard2008Inngår i: Appita journal, ISSN 1038-6807, Vol. 61, nr 6, s. 468-471Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    When load is applied to any type of paper while varying the relative humidity, the paper will creep more than if the same load is applied at constant humidity. This behaviour is called mechano-sorptive creep or accelerated creep, and the reasons for its occurrence in paper are still not fully understood. However, wet strength and the addition of apolar (hydrophobic) compounds to sheets have previously been suggested as factors improving the mechano-sorptive creep performance.

    This work evaluates a method for improving wet strength and tests the addition of a hydrophobic compound, with particular reference to mechano-sorptive creep stiffness. Wet strength was improved by subjecting kraft liner pulp to low-molecular-weight lignin, obtained by cross-flow filtration, and to the radical initiator manganese(III). The hydrophobic compound added was a suberin-like lignin derivative. Adding the suberin-like lignin derivative significantly increased the mechano-sorptive creep stiffness, even though the stiffness at 90% rh decreased in the tested samples. This was probably because of the decrease in hygroexpansion caused by this hydrophobic additive.

    Even though it is possible significantly to increase the wet strength of kraft liner pulp by adding manganese(III) and cross-flow-filtered lignin, doing so has no significant effect on mechano-sorptive creep stiffness.

  • 9.
    Antonsson, Stefan
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Träkemi och massateknologi.
    Henriksson, Gunnar
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Träkemi och massateknologi.
    Lindström, Mikael E.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Träkemi och massateknologi.
    The influence of lignin and xylan on some kraftliner pulp properties2009Inngår i: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 24, nr 4, s. 403-408Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This study investigates the influence of lignin and hemicellulose content on the mechanical and physical properties of softwood kraft liner pulp. Tensile properties, hygroexpansion, and mechano-sorptive creep properties were measured. The lignin and hemicellulose contents were modified by chlorite delignification and xylanase treatment.

    After treatment, the chemical composition of the pulps was 3-14% Klason lignin, 69-77% cellulose, 16-21% hemicellulose, and 4-7% xylan. In the tested pulps, low lignin content tended to decrease hygroexpansion as well as increase tensile stiffness and mechano-sorptive creep stiffness. Xylan contributed less to the pulp sheet properties, but at equal lignin contents, higher xylan content tended to give increased hygroexpansion and worse mechano-sorptive creep properties.

  • 10.
    Antonsson, Stefan
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Träkemi och massateknologi.
    Karlström, Katarina
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Träkemi och massateknologi.
    Lindström, Mikael E.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Träkemi och massateknologi.
    Applying a novel cooking technique to produce high kappa number pulps: the effects on physical properties2009Inngår i: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 24, nr 4, s. 415-420Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A recently developed kraft cooking technique, with a longer impregnation time at lower temperatures to facilitate diffusion over consumption of active cooking chemicals, makes it possible to produce kraftliner pulp without inline refining. This technique was applied to prepare two pulps with different lignin contents, which were compared with two industrial pulps from conventional kraft cooks in order to evaluate the physical properties of the pulps.

    It was demonstrated that pulps with lower lignin content can increase tensile stiffness, decrease hygroexpansion, and decrease the mechano-sorptive creep of handsheets. However, no difference in SCT and tensile energy absorption values due to different lignin contents was observed. It was further demonstrated that pulps made with Extended Impregnation Cooking (EIC) results in straighter pulp fibres with higher cellulose content. These pulps tended to have lower mechano-sorptive creep than conventional pulps. A higher brightness of the pulp sheets can also be obtained by choosing a higher alkali profile.

  • 11.
    Antonsson, Stefan
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Träkemi och massateknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Mäkelä, Petri
    Innventia AB.
    Fellers, Christer
    Innventia AB.
    Lindström, Mikael E.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Träkemi och massateknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Comparison of the physical properties between hardwood and softwood pulps2009Inngår i: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 24, nr 4, s. 409-414Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    High mechano-sorptive creep resistance, i.e., good creep resistance in environments with changing relative humidity, is one of the key requirements for linerboards. The aim of this study was to investigate the influence of pulp types and pulp properties on the mechano-sorptive creep of kraftliner. A high-yield softwood, kraftliner pulp, and four different hardwood pulps were investigated. The physical properties of laboratory sheets were evaluated, with emphasis on the mechano-sorptive creep properties.

    The results showed that the density increase due to increased beating significantly improved the tensile stiffness of all pulps, while its effect on the isocyclic creep stiffness was less pronounced. The hardwood pulps showed higher tensile stiffness, better mechano-sorptive creep properties, and lower hygroexpansion than the softwood pulp at a given density. However, the softwood pulp did exhibit better tensile strength and fracture toughness properties than the hardwood pulps.

    The results imply that hardwood pulps can be competitive with softwood pulps in kraftliners, provided that their tensile strength and fracture toughness properties can be improved by, for example, chemical means. Furthermore, the isocyclic creep stiffness correlates with the ratio of tensile stiffness to hygroexpansion, indicating that this ratio can be used for engineering estimates of the mechano-sorptive creep performance of paper materials.

  • 12.
    Antonsson, Stefan
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Träkemi och massateknologi.
    Pulkkinen, Iiro
    Chemical Engineering, Department of Biotechnology and Chemical Technology, Helsinki University of Technology (TKK), Espoo, Finland.
    Fiskari, Juha
    Metsä-Botnia, Joutseno Mill, Lappeenranta, Finland.
    Karlström, Katarina
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Träkemi och massateknologi.
    Lindström, Mikael E.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Träkemi och massateknologi.
    The relationship between hygroexpansion, tensile stiffness, and mechano–sorptive creep in bleached hardwood kraft pulps2010Inngår i: Appita journal, ISSN 1038-6807, Vol. 63, nr 1, s. 231-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Hygroexpansion coefficient and tensile stiffness are important parameters in many paper applications. This study compares several bleached industrial hardwood kraft pulps, comprising five eucalypt pulps from South America, Europe, and Africa as well as an acacia pulp from Asia and a birch pulp from Scandinavia. Refined and unrefined pulps are compared. The results indicate significant differences in hygroexpansion but smaller differences in tensile stiffness index at comparable densities. No single factor offering a reasonable explanation of these differences in hygroexpansion coefficient, such as carbohydrate composition, fibre dimensions, or fibre form, was found. However, correlation between hygroexpansion coefficient and the mechano-sorptive creep stiffness was observed. We suggest that the hygroexpansion coefficient at a given tensile stiffness level can be used to rank pulps in terms of their mechano-sorptive creep properties.

  • 13. Axelsson, P.
    et al.
    Berggren, R.
    Berthold, F.
    Lindström, Mikael
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Träkemi och massateknologi.
    Molecular mass distributions of lignin and lignin-carbohyd rate complexes in birch Kraft pulps: Changes caused by the conditions in the cook and their relation to unbleached pulp brightness and bleachability2005Inngår i: Journal of Pulp and Paper Science (JPPS), ISSN 0826-6220, Vol. 31, nr 1, s. 19-27Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Lignin-carbohydrate complexes and their relationship to pulp bleachability and unbleached pulp brightness were studied in four birch kraft pulps produced at high and low hydroxide ion and sodium ion concentrations, using size-exclusion chromatography (SEC). About 75-80%of the lignin was found to be associated with carbohydrates, a larger part with hemicelluloses and a smaller part with cellulose. Easily bleached pulps, produced under high [OH-] or low [Na+] conditions, had more lignin associated with cellulose than their counterparts. Furthermore, a high [OH-] gave a residual lignin that was significantly more accessible in the residual lignin isolation, and where the inaccessible lignin was bonded to carbohydrates. Colour differences of pulps caused by variations in the cooking conditions, as studied in the SEC system, were associated with all the lignin, irrespective of whether it was associated with hemicelluloses or cellulose.

  • 14.
    Axelsson, Patrik
    et al.
    KTH, Tidigare Institutioner (före 2005), Pappers- och massateknik.
    Gellerstedt, Göran
    KTH, Tidigare Institutioner (före 2005), Pappers- och massateknik.
    Lindström, Mikael
    KTH, Tidigare Institutioner (före 2005), Fiber- och polymerteknologi.
    Condensation reactions of lignin during birch Kraft pulping as studied by thioacidolysis2004Inngår i: Journal of Pulp and Paper Science (JPPS), ISSN 0826-6220, Vol. 30, nr 12, s. 317-322Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The influences of kappa number and ionic strength during birch kraft cooking on the extent of lignin condensation have been studied using thioacidolysis and size exclusion chromatography. Thioacidolysis degrades alkyl-aryl ether bonds in lignin while leaving carbon-carbon and diaryl-ether bonds relatively intact. Therefore, the lignin structures not cleaved during thioacidolysis can be considered as relatively stable and may account,, for example,for the slow residual phase delignification in the kraft cook and for differences in bleachability. It was shown that condensed lignin structures are formed in the residual lignin during birch kraft cooking. The relative amount of such structures increased with decreasing kappa number or with increasing sodium ion concentration in the cook. These structures were also found in a xylan-lignin complex isolated from a birch kraft pulp. The condensed structures were only partly reactive during oxygen delignification.

  • 15.
    Axelsson, Patrik
    et al.
    KTH, Tidigare Institutioner (före 2005), Fiber- och polymerteknologi.
    Lindström, Mikael
    KTH, Tidigare Institutioner (före 2005), Fiber- och polymerteknologi.
    Influence of the conditions during birch kraft cooking on unbleached brightness, and on ECF- and TCF-bleachability2004Inngår i: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 19, nr 3, s. 309-317Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The influences on ECF and TCF bleachability of the hydroxide ion, hydrogen sulphide ion and sodium ion concentrations as well as of the amount of dissolved wood components (DWC) in a birch kraft cook were investigated. The pulping was carried out using a so-called constant composition cooking technique, where a high liquor-to-wood ratio enables an almost constant concentration of the cooking chemicals during the entire cook. This cooking method also renders possible to vary each cooking variable separately. The pulps were oxygen-delignified and bleached in a D(EOP)DD and a Q(OP)Q(PO) sequence. The presence of DWC caused a significant rate increasing effect on the delignification. An increase in hydroxide ion concentration, an increase in hydrogen sulphide ion concentration or a decrease in sodium ion concentration improved both the ECF and the TCF bleachability, but the DWC had no significant effect on the bleachability. Further a correlation was found between the bleachability and the brightness of the oxygen-delignified pulp.

  • 16.
    Azhar, Shoaib
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Träkemi och massateknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Henriksson, Gunnar
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Träkemi och massateknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Theliander, Hans
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center. Chalmers University of Technology, Sweden.
    Lindström, Mikael
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Träkemi och massateknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Extraction of hemicelluloses from fiberized spruce wood2015Inngår i: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 117, s. 19-24Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A novel mechanical pre-treatment method was used to separate the wood chips into fiber bundles in order to extract high molecular weight wood polymers. The mechanical pre-treatment involved chip compression in a conical plug-screw followed by defibration in a fiberizer. The fiberized wood was treated with hot water at various combinations of time and temperature in order to analyze the extraction yield of hemicelluloses at different conditions. Nearly 6 mg/g wood of galactoglucomannan was obtained at 90◦C/120min which was about three times more than what could be extracted from wood chips. The extracted carbohydrates had molecular weight ranging up to 60 kDa. About 10% of each of the extracted material had a molecular weight above 30 kDa. The extraction liquor could also be reused for consecutive extractions with successive increase in the extraction yield of hemicelluloses. 

  • 17.
    Azhar, Shoaib
    et al.
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Wang, Yan
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Lawoko, Martin
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Henriksson, Gunnar
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Lindström, Mikael
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Extraction of polymers from enzyme-treated softwood2011Inngår i: BioResources, ISSN 1930-2126, E-ISSN 1930-2126, Vol. 6, nr 4, s. 4606-4614Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In a biorefinery context it is an advantage to fractionate and extract different wood components in a relatively pure form. However, one major obstacle for efficient extraction of wood polymers (lignin, polysaccharides etc.) is the covalent lignin-polysaccharide networks present in lignified cell walls. Enzymatic catalysis might be a useful tool for a controlled degradation of these networks, thereby enhancing the extraction of high molecular weight polymers. In this work, a methanol-alkali mixture was used to extract two different wood samples treated with endoxylanase and gammanase, respectively. Wood chips were pretreated with alkali prior to enzymatic treatment to enhance the cell-wall accessibility to enzymes. Extractions were also carried out on non-enzyme-treated samples to evaluate the enzymatic effects. Results showed that the enzymatic treatment increased the extraction yield, with gammanase as the more efficient of the two enzymes. Furthermore, polymers extracted from xylanase-treated wood had a higher degree of polymerization than the reference.

  • 18.
    Azhar, Shoaib
    et al.
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Wang, Yan
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Lawoko, Martin
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Henriksson, Gunnar
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Lindström, Mikael E.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Enhanced extraction of high-molecular-weight wood polymers with chemoenzymatic treatment2012Inngår i: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 243Artikkel i tidsskrift (Annet vitenskapelig)
  • 19.
    Azhar, Shoaib
    et al.
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Wang, Yan
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Lawoko, Martin
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Henriksson, Gunnar
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Lindström, Mikale E
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Chemoenzymatic separation of softwood polymers2011Inngår i: Proceedings of  the 16th international symposium of wood, fiber and pulp chemistry / [ed] Lijun Wan et al., 2011, s. 932-936Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Spruce wood chips were chemically pre-treated with sodium hydroxide to open up the compact structure of wood. The wood was then treated with enzymes (xylanase, gamanase and mannanase) and subjected to extraction with a mixture of methanol and alkali to efficiently isolate lignin and hemicelluloses. Chemical pre-treatment improved enzyme efficiency which consequently enhanced the extraction of lignocelluloses with higher average molar mass than the references.

  • 20. Bandekar, R.
    et al.
    Oldmark, A.
    Lindström, Mikael
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Kallen, L.
    Liedberg, J.
    Foan, J.
    Wearing, J.
    Cross flow filtration of green liquor for increased pulp production, improved green liquor quality, and energy savings2020Inngår i: PEERS/IBBC Virtual Conference 2020, TAPPI Press , 2020, s. 336-349Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A new green liquor filtration system has been installed and commissioned at the Ence pulp mill in Pontevedra, Spain. The filtration system is based on microfiltration and was developed in collaboration with the KTH Royal Institute of Technology in Stockholm, Sweden. The patented method for efficient purification of green liquor decreases the NPE content by providing more efficient solids/liquid separation, reducing energy and chemical consumption in pulp mills, and could lead to increased production capacity by eliminating certain capacity bottlenecks. The process has been tested at the Aspa Bruk Mill outside Askersund Sweden continuously since 2013. The technology has proven to create nearly particulate free green liquor during the purification process. The technology can also be used to polish white liquor to provide higher pulp quality. To provide for a simple cost-effective installation, the system was designed as a skid mounted unit pre-piped, instrumented, and tested before shipment. The system is modular and allows for easy expansion of capacity. This paper discusses the process design, process integration, and startup of the new system, along with experiences for the first months of operation.

  • 21.
    Bandekar, R.
    et al.
    NORAM Engn & Constructors Ltd, Pulp & Paper, Vancouver, BC, Canada.
    Oldmark, A.
    BillerudKorsnäs AB, Solna, Sweden.
    Lindström, Mikael
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Kallen, L.
    CleanFlow BLACK AB, Forshaga, Sweden.
    Liedberg, J.
    NORAM Int AB, Gothenburg, Sweden.
    Foan, J.
    NORAM Engn & Constructors Ltd, Pulp & Paper, Vancouver, BC, Canada.
    Wearing, J.
    NORAM Engn & Constructors Ltd, Pulp & Paper, Vancouver, BC, Canada.
    Crossflow filtration of green liquor for increased pulp production, improved green liquor quality, and energy savings2020Inngår i: TAPPI Journal, ISSN 0734-1415, Vol. 19, nr 10, s. 527-538Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A new green liquor filtration system has been installed and commissioned at the Ence pulp mill in Pontevedra, Spain. The filtration system is based on microfiltration and was developed in collaboration with the KTH Royal Institute of Technology in Stockholm, Sweden. The patented method for efficient purification of green liquor decreases the non-process element (NPE) content by providing more efficient solids/liquid separation, reducing energy and chemical consumption in pulp mills and increasing production capacity by eliminating certain capacity bottlenecks. The process has been continuously tested at the Aspa Bruk Mill outside Askersund, Sweden, since 2013. The technology has proven to create nearly particulate-free green liquor during the purification process. The technology can also be used to polish white liquor to provide higher pulp quality. To provide for a simple and cost-effective installation, the system was designed as a skid-mounted unit that is pre-piped, instrumented, and tested before shipment. The system is modular and allows for easy expansion of capacity. This paper discusses the process design, process integration, and startup of the new system, along with experi-ences from the first months of operation. Application: The patented and trademarked CleanFlow system is a technology designed to increase the capacity of a kraft mill recausticizing plant. Crossflow ceramic membranes are used to filter a portion of the green liquor, debottlenecking the existing green liquor clarifiers’ filters. The liquor quality is improved by reducing the buildup of NPEs. CleanFlow can also be implemented to filter white liquor, either the entire stream for improved pulp quality or just a portion, such as with preparing oxidized white liquor for pulp delignification after cooking, or for scrubbing of bleaching system vents.

  • 22.
    Berglund, Jennie
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Angles d’Ortoli, Thibault
    Vilaplana, Francisco
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Widmalm, Göran
    Bergenstråhle-Wohlert, Malin
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Lawoko, Martin
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Henriksson, Gunnar
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Lindström, Mikael
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Wohlert, Jakob
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    A molecular dynamics study of the effect of glycosidic linkage type in the hemicellulose backbone on the molecular chain flexibility2016Inngår i: The Plant Journal, ISSN 0960-7412, E-ISSN 1365-313XArtikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The macromolecular conformation of the constituent polysaccharides in lignocellulosic biomass influences their supramolecular interactions, and therefore their function in plants and their performance in technical products. The flexibility of glycosidic linkages from the backbone of hemicelluloses was studied by evaluating the conformational freedom of the φ and ψ dihedral angles using molecular dynamic simulations, additionally selected molecules were correlated with experimental data by nuclear magnetic resonance spectroscopy. Three types of β-(1→4) glycosidic linkages involving the monosaccharides (Glcp, Xylp and Manp) present in the backbone of hemicelluloses were defined. Different di- and tetrasaccharides with combinations of such sugar monomers from hemicelluloses were simulated, and free energy maps of the φ – ψ space and hydrogen-bonding patterns were obtained. The glycosidic linkage between Glc-Glc or Glc-Man (C-type) was the stiffest with mainly one probable conformation; the linkage from Man-Man or Man-Glc (M-type) was similar but with an increased probability for an alternative conformation making it more flexible, and the linkage between two Xyl-units (X-type) was the most flexible with two almost equally populated conformations. Glycosidic linkages of the same type showed essentially the same conformational space in both disaccharides and in the central region of tetrasaccharides. Different probabilities of glycosidic linkage conformations in the backbone of hemicelluloses can be directly estimated from the free energy maps, which to a large degree affect the overall macromolecular conformations of these polymers. The information gained contributes to an increased understanding of the function of hemicelluloses both in the cell wall and in technical products.

  • 23.
    Berglund, Jennie
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Azhar, Shoaib
    Lawoko, Martin
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Lindström, Mikael
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Vilaplana, Francisco
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Wohlert, Jakob
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Henriksson, Gunnar
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    The structure of galactoglucomannan impacts the degradation under alkaline conditions2018Inngår i: Cellulose, ISSN 0969-0239, E-ISSN 1572-882XArtikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

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

  • 24.
    Berglund, Jennie
    et al.
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Berqenstråhle, Malin
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Vilaplana, Francisco
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center. KTH, Skolan för bioteknologi (BIO), Centra, Albanova VinnExcellence Center for Protein Technology, ProNova. KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    d'Ortoli, Thibault Angles
    Stockholm Univ, Dept Organ Chem, Stockholm, Sweden..
    Widmalm, Goran
    Stockholm Univ, Dept Organ Chem, Stockholm, Sweden..
    Lawoko, Martin
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Henriksson, Gunnar
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Lindström, Mikael
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Wohlert, Jakob
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    How the flexibility properties of hemicelluloses are affected by the glycosidic bonds between different backbone sugars - A molecular dynamics study2016Inngår i: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 251Artikkel i tidsskrift (Annet vitenskapelig)
  • 25.
    Berglund, Jennie
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH).
    Farahani, Saina Kishani
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH).
    de Carvalho, Danila Morais
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Träkemi och massateknologi.
    Lawoko, Martin
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Wohlert, Jakob
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Biokompositer.
    Henriksson, Gunnar
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Lindström, Mikael
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Wågberg, Lars
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Vilaplana, Francisco
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap.
    Acetylation and Sugar Composition Influence the (In)Solubility of Plant beta-Mannans and Their Interaction with Cellulose Surfaces2020Inngår i: ACS Sustainable Chemistry and Engineering, E-ISSN 2168-0485, Vol. 8, nr 27, s. 10027-10040Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Plant beta-mannans are complex heteropolysaccharides that represent an abundant resource from lignocellulosic biomass. The influence of the molecular motifs of plant mannans on the backbone flexibility, solubility, and the interaction with cellulose was investigated by computational and experimental approaches. The regioselectivity of the acetyl substitutions at C2 and C3 distinctively influenced backbone flexibility in aqueous media, as revealed by molecular dynamic simulations. The molecular weight and degree of acetylation were tailored for two model seed mannans (galactomannan and glucomannan) and compared to spruce acetylated galactoglucomannan. The thermal stability was enhanced with increasing acetyl substitutions, independently of the type of mannan. Dynamic light scattering and atomic force microscopy revealed that the occurrence of galactosylation and a low degree of acetylation (similar to that of native acetylated galactoglucomannans) enhanced solubility/dispersibility of mannans, whereas the solubility/dispersibility decreased for higher degrees of acetylation. Mannan solubility influenced their interactions with cellulose at water-cellulose interfaces in terms of adsorbed mass and viscoelastic properties of the adsorbed mannan layers. Our results reveal that modulating the molecular motifs of plant beta-mannans influences their macromolecular conformation and physicochemical properties, with fundamental implications for their role in the plant cell wall and the design of wood-based materials.

  • 26.
    Berglund, Jennie
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Farahani, Saina Kishani
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    de Carvalho, Danila Morais
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Lawoko, Martin
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Wohlert, Jakob
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Henriksson, Gunnar
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Lindström, Mikael
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Wågberg, Lars
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Vilaplana, Francisco
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap. AlbaNova University Centre.
    The influence of acetylation and sugar composition on the (in)solubility of mannans, their interaction with cellulose surfaces and thermal propertiesManuskript (preprint) (Annet vitenskapelig)
  • 27.
    Berglund, Jennie
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Kishani, Saina
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    de Carvalho, Danila Morais
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Lawoko, Martin
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Wohlert, Jakob
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Henriksson, Gunnar
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Lindström, Mikael
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Wågberg, Lars
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Vilaplana, Francisco
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap.
    The influence of acetylation and sugar composition on the (in)solubility of mannans, their interaction with cellulose surfaces and thermal properties.Manuskript (preprint) (Annet vitenskapelig)
  • 28.
    Berglund, Jennie
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Mikkelsen, Deidre
    Flanagan, Bernadine M.
    Dhital, Sushil
    Gaunitz, Stefan
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Henriksson, Gunnar
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Lindström, Mikael
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Yakubov, Gleb E.
    Gidley, Michael J.
    Vilaplana, Francisco
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Wood hemicelluloses exert distinct biomechanical contributions to cellulose fibrillar networks2020Inngår i: Nature Communications, E-ISSN 2041-1723, Vol. 11, nr 1, artikkel-id 4692Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Hemicelluloses, a family of heterogeneous polysaccharides with complex molecular structures, constitute a fundamental component of lignocellulosic biomass. However, the contribution of each hemicellulose type to the mechanical properties of secondary plant cell walls remains elusive. Here we homogeneously incorporate different combinations of extracted and purified hemicelluloses (xylans and glucomannans) from softwood and hardwood species into self-assembled networks during cellulose biosynthesis in a bacterial model, without altering the morphology and the crystallinity of the cellulose bundles. These composite hydrogels can be therefore envisioned as models of secondary plant cell walls prior to lignification. The incorporated hemicelluloses exhibit both a rigid phase having close interactions with cellulose, together with a flexible phase contributing to the multiscale architecture of the bacterial cellulose hydrogels. The wood hemicelluloses exhibit distinct biomechanical contributions, with glucomannans increasing the elastic modulus in compression, and xylans contributing to a dramatic increase of the elongation at break under tension. These diverging effects cannot be explained solely from the nature of their direct interactions with cellulose, but can be related to the distinct molecular structure of wood xylans and mannans, the multiphase architecture of the hydrogels and the aggregative effects amongst hemicellulose-coated fibrils. Our study contributes to understanding the specific roles of wood xylans and glucomannans in the biomechanical integrity of secondary cell walls in tension and compression and has significance for the development of lignocellulosic materials with controlled assembly and tailored mechanical properties.

  • 29.
    Berglund, Jennie
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Mikkelsen, Deirdre
    Univ Queensland, Queensland Alliance Agr & Food Innovat, Ctr Nutr & Food Sci, ARC Ctr Excellence Plant Cell Walls, Brisbane, Qld, Australia..
    Flanagan, Bernadine
    Univ Queensland, Queensland Alliance Agr & Food Innovat, Ctr Nutr & Food Sci, ARC Ctr Excellence Plant Cell Walls, Brisbane, Qld, Australia..
    Dhital, Sushil
    Univ Queensland, Queensland Alliance Agr & Food Innovat, Ctr Nutr & Food Sci, ARC Ctr Excellence Plant Cell Walls, Brisbane, Qld, Australia..
    Henriksson, Gunnar
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Lindström, Mikael
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Yakubov, Gleb
    Univ Queensland, Sch Chem Engn, ARC Ctr Excellence Plant Cell Walls, Brisbane, Qld, Australia..
    Gidley, Michael
    Univ Queensland, Queensland Alliance Agr & Food Innovat, Ctr Nutr & Food Sci, ARC Ctr Excellence Plant Cell Walls, Brisbane, Qld, Australia..
    Vilaplana, Francisco
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Hydrogels of bacterial cellulose and wood hemicelluloses as a model of plant secondary cell walls2019Inngår i: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 257Artikkel i tidsskrift (Annet vitenskapelig)
  • 30.
    Berglund, Jennie
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Mikkelsen, Deirdre
    University of Queensland, Australia.
    Flanagan, Bernadine M.
    University of Queensland, Australia.
    Dhital, Sushil
    University of Queensland, Australia.
    Henriksson, Gunnar
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Lindström, Mikael
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Yakubov, Gleb E.
    University of Queensland, Australia.
    Gidley, Michael J.
    University of Queensland, Australia.
    Vilaplana, Francisco
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Wood Hemicelluloses Exert Distinct Biomechanical Contributions in Bacterial Cellulose HydrogelsManuskript (preprint) (Annet vitenskapelig)
  • 31. Berthold, F
    et al.
    Gustafsson, K
    Berggren, R
    Sjoholm, E
    Lindström, Mikael
    Swed. Pulp/Paper Research Institute.
    Dissolution of softwood kraft pulps by direct derivatization in lithium chloride/N,N-dimethylacetamide2004Inngår i: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 94, nr 2, s. 424-431Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A method for the characterization of the molar mass distributions (MMDs) of softwood kraft pulps dissolved in 0.5% lithium chloride (LiCl)/N,N-dimethylacetamide (DMAc) by size exclusion chromatography is presented. The method is based on derivatization with ethyl isocyanate and the dissolution of samples in 8% LiCl/DMAc. In this study, the derivatization of hardwood kraft pulps did not influence the MMD. In the case of softwood pulps, however, the derivatization decreased the proportion of the high-molecular-mass material and increased the proportion of the low-molecular-mass material, which resulted in a distribution similar to the MMD of a hardwood kraft pulp. The results suggest that associations between hemicellulose and cellulose in the softwood kraft pulp were ruptured during derivatization. This led to a more correct estimation of the MMD of derivatized softwood kraft pulps than obtained by the dissolution of nonderivatized samples. This new method offers several advantages over derivatization with phenyl isocyanate: a precipitation step is not necessary, it is possible to follow the lignin distribution in the samples, and the method allows very high levels of dissolution of softwood kraft pulps up to a kappa number of around 50.

  • 32.
    Brännvall, Elisabet
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Eriksson, Malin
    Lindström, Mikael
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Wågberg, Lars
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Fibre surface modifications of market pulp by consecutive treatments with cationic and anionic starch2007Inngår i: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 22, nr 2, s. 244-248Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Bleached softwood kraft pulps were coated with one to three layers of starch, which lead to tensile strength improvement. The strength increase was larger when a never-dried pulp was treated compared to treatment of a once-dried pulp, although equal amounts of starch were adsorbed in both cases. When the never-dried, starch-treated pulp was dried and subsequently reslushed, its tensile strength was higher than that of the never-dried reference pulp. It also required less PFI beating to reach a certain tensile index. Starch-treatment can thereby be a way of improving the tensile strength and beatability of market pulp.

  • 33.
    Brännvall, Elisabet
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Lindström, Mikael
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    A study on the difference in strength between industrially and laboratory-cooked pulp2006Inngår i: Nordic pulp and paper research journal, ISSN 0283-2631, Vol. 21, nr 2, s. 222-226Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The tensile strength levels of industrially produced pulp and corresponding laboratory-cooked pulps were investigated. The industrial pulp had a lower tensile strength, which could not be explained by fibre form or fibre strength.

    It was concluded that bonding strength was the limiting factor for the tensile strength of the industrial pulp. The industrial pulp, despite of its higher hemicellulose content, had a lower surface charge. The xylan precipitated onto the fibres during the industrial cook was probably more degraded and consequently with lower degree of polymerisation and fewer charged groups.

  • 34.
    Brännvall, Elisabet
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Lindström, Mikael
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    A study on the difference industrially and in tensile strength between laboratory-cooked pulp2006Inngår i: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 21, nr 2, s. 222-226Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The tensile strength levels of industrially produced pulp and corresponding laboratory-cooked pulps were investigated. The industrial pulp had a lower tensile strength, which could not be explained by fibre form or fibre strength. It was concluded that bonding strength was the limiting factor for the tensile strength of the industrial pulp. The industrial pulp, despite of its higher hemicellulose content, had a lower surface charge. The xylan precipitated onto the fibres during the industrial cook was probably more degraded and consequently with lower degree of polymerisation and fewer charged groups.

  • 35.
    Brännvall, Elisabet
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Lindström, Mikael
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    The hemicellulose composition of pulp fibers and their ability to endure mechanical treatment2007Inngår i: TAPPI Journal, ISSN 0734-1415, Vol. 6, nr 10, s. 19-24Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Two pulps of different hemicellulose content were subjected to high-intensity shear forces in a laboratory mixer to damage the fibers. The, ability of the fibers to resist the mechanical treatment was evaluated by comparing their strength that of undamaged pulps. The study showed that pulp produced at high hydroxide ion concentration, which resulted in lower xylan and, higher glucomannan content, was sensitive to mechanical treatment. The pulp strength decreased, evaluated as tear versus tensile index and as rewetted zero-span tensile index. Pulp with a higher xylan and lower glucomannan content could be subjected to mechanical treatment without losing strength.

  • 36.
    Brännvall, Elisabet
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Lindström, Mikael
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    The impact of ionic strength during kraft cooking on the strength properties of softwood kraft pulp2007Inngår i: Appita journal, ISSN 1038-6807, Vol. 60, nr 1, s. 60-64Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A study was undertaken in order to investigate the influence of ionic strength during pulping (measured as sodium ion concentration) on pulp strength (evaluated as tear index vs. tensile index) and on the pulps ability to resist mechanical damage. Sodium chloride was added to the cooking liquor in order to control the ionic strength during the laboratory kraft cooking of soft-wood. The strength properties were compared to a conventional laboratory pulp, pulped at an ionic strength equal to that originating solely from the cooking chemicals added.

    It was shown that the ionic strength of the cooking liquor had an impact on pulp strength. Tear index at a certain tensile index decreased at higher ionic strength. The fibre strength, measured as rewetted zero-span tensile index, also decreased. Furthermore, high ionic strength during cooking rendered the fibres more vulnerable to mechanical damage.

  • 37.
    Budnyak, Tetyana
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Aminzadeh, Selda
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Pylypchuk, Ievgen
    Department of Molecular Sciences, Swedish University of Agricultural Sciences (SLU), Allmas alle 5, SE-750 07 Uppsala, Swede.
    Riazanova, Anastasiia
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Tertykh, Valentin
    Chuiko Institute of Surface Chemistry, National Academy of Sciences of Ukraine, 17 General Naumov Str., 03164 Kyiv, Ukraine.
    Lindström, Mikael
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Sevastyanova, Olena
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Peculiarities of synthesis and properties of lignin-silica nanocomposites prepared by sol-gel method2018Inngår i: Nanomaterials, E-ISSN 2079-4991, Vol. 8, nr 11, s. 1-18, artikkel-id 950Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The development of advanced hybrid materials based on polymers from biorenewable sources and mineral nanoparticles is currently of high importance. In this paper, we applied softwood kraft lignins for the synthesis of lignin/SiO2 nanostructured composites. We described the peculiarities of composites formation in the sol-gel process through the incorporation of the lignin into a silica network during the hydrolysis of tetraethoxysilane (TEOS). The initial activation of lignins was achieved by means of a Mannich reaction with 3-aminopropyltriethoxysilane (APTES). In the study, we present a detailed investigation of the physicochemical characteristics of initial kraft lignins and modified lignins on each step of the synthesis. Thus, 2D-NMR, P-31-NMR, size-exclusion chromatography (SEC) and dynamic light scattering (DLS) were applied to analyze the characteristics of pristine lignins and lignins in dioxan:water solutions. X-Ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) were used to confirm the formation of the lignin-silica network and characterize the surface and bulk structures of the obtained hybrids. Termogravimetric analysis (TGA) in nitrogen and air atmosphere were applied to a detailed investigation of the thermal properties of pristine lignins and lignins on each step of modification. SEM confirmed the nanostructure of the obtained composites. As was demonstrated, the activation of lignin is crucial for the sol-gel formation of a silica network in order to create novel hybrid materials from lignins and alkoxysilanes (e.g., TEOS). It was concluded that the structure of the lignin had an impact on its reactivity during the activation reaction, and consequently affected the properties of the final hybrid materials.

    Fulltekst (pdf)
    Peculiarities of Synthesis and Properties of Lignin–Silica Nanocomposites Prepared by Sol-Gel Method
  • 38.
    Budnyak, Tetyana M.
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. Natl Acad Sci Ukraine, Chuiko Inst Surface Chem, 17 Gen Naumov Str, UA-03164 Kiev, Ukraine..
    Aminzadeh, Selda
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Pylypchuk, Ievgen V.
    Swedish Univ Agr Sci SLU, Dept Mol Sci, Allmas Alle 5, SE-75007 Uppsala, Sweden..
    Sternik, Dariusz
    Marie Curie Sklodowska Univ, 2 M Curie Sklodowska Sq, PL-20031 Lublin, Poland..
    Tertykh, Valentin A.
    Natl Acad Sci Ukraine, Chuiko Inst Surface Chem, 17 Gen Naumov Str, UA-03164 Kiev, Ukraine..
    Lindström, Mikael E.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Sevastyanova, Olena
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Methylene Blue dye sorption by hybrid materials from technical lignins2018Inngår i: Journal of Environmental Chemical Engineering, E-ISSN 2213-3437, Vol. 6, nr 4, s. 4997-5007Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    New hybrid sorbents were synthesized from technical lignins and silica and were applied for the removal of Methylene Blue dye (MB) from aqueous solution. Kraft softwood lignins from LignoBoost (LBL) and CleanFlowBlack (CFBL) processes were used to understand the influence of molecular weight and functionality of initial lignins on the properties of the final hybrids. The synthesized materials were applied as adsorbents for the removal of MB from aqueous solutions. The effects of parameters such as contact time, initial concentration of dye and initial pH on the adsorption capacity were evaluated. The hybrids exhibited higher adsorption capacity than the initial macromolecules of lignin with respect to MB. The hybrid based on CFBL exhibited an adsorption capacity of 60 mg/g; this value was 30% higher than the capacity of the hybrid based on LBL, which was 41.6 mg/g. Lignin hybrid materials extract 80-99% of the dye in a pH range from 3 to 10. The equilibrium and kinetic characteristics of MB uptake by the hybrids followed the Langmuir isotherm model and pseudosecond-order model, rather than the Freundlich and Temkin models, the pseudo-first-order or the intraparticle diffusion model. The attachment of the dye to the hybrid surface was confirmed via FE-SEM and FTIR spectroscopy. The mechanism for MB adsorption was proposed. Due to the high values of regeneration efficiency of the surface of both lignin-silica hybrid materials in 0.1 M HCl (up to 75%) and ethanol (99%), they could be applied as effective sorbents in industrial wastewater treatment processes.

  • 39.
    Budnyak, Tetyana M.
    et al.
    Stockholm Univ, Dept Mat & Environm Chem, S-10691 Stockholm, Sweden..
    Modersitzki, Sina
    Stockholm Univ, Dept Mat & Environm Chem, S-10691 Stockholm, Sweden..
    Pylypchuk, Ievgen
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Träkemi och massateknologi.
    Piatek, Jedrzej
    Stockholm Univ, Dept Mat & Environm Chem, S-10691 Stockholm, Sweden..
    Jaworski, Aleksander
    Stockholm Univ, Dept Mat & Environm Chem, S-10691 Stockholm, Sweden..
    Sevastyanova, Olena
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Lindström, Mikael
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Slabon, Adam
    Stockholm Univ, Dept Mat & Environm Chem, S-10691 Stockholm, Sweden..
    Tailored Hydrophobic/Hydrophilic Lignin Coatings on Mesoporous Silica for Sustainable Cobalt(II) Recycling2020Inngår i: ACS Sustainable Chemistry and Engineering, E-ISSN 2168-0485, Vol. 8, nr 43, s. 16262-16273Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Lignin is a renewable biopolymer, and its chemical functionalization renders it a prospective material for a plethora of applications. Within this respect, we present a method for lignin immobilization on the surface of mesoporous silica. Two types of lignins were used to prove the feasibility of the fabrication of either hydrophilic or hydrophobic biocoatings on silica. The procedure permits to immobilize 17 mg of lignosulfonate (LS) or 37 mg of kraft lignin (KL) per gram of silica. The bioinorganic composites display a synergistic effect in the adsorption of cobalt(II) ions from aqueous solutions because the adsorption efficiency outperforms the individual constituents. These results demonstrate that thin lignin overlayers, exhibiting polymer concentrations of 0.07 mg.m(-2) for LS-SiO2, and 0.14 mg.m(-2) for KL-SiO2, provide new functionality in comparison to bulk lignin and metal oxides. According to the Langmuir isotherm model, the adsorption capacity toward aqua complexes of Co(II) was found to be 75 and 59 mg.g(-1) for the LS- or KL-coated silica, respectively. The kinetic study revealed that lignin-SiO2 composites gained the features of inorganic sorbents because 1-1.5 h was sufficient for effective cobalt extraction. The adsorption on the bioinorganic composites proceeds with the pseudo-second-order kinetics model. The adsorption of Co(II) ions was confirmed by means of solid-state H-1 magic-angle spinning (MAS) NMR spectroscopy. The simplicity of the synthesis, low-cost and abundancy of substrates, high capacity, and fast kinetics make such lignin-coated silica a promising material for cobalt recovery.

  • 40.
    Budnyak, Tetyana M.
    et al.
    Stockholm Univ, Dept Mat & Environm Chem, Svante Arrhenius Vag 16C, S-10691 Stockholm, Sweden..
    Onwumere, Joy
    Stockholm Univ, Dept Mat & Environm Chem, Svante Arrhenius Vag 16C, S-10691 Stockholm, Sweden..
    Pylypchuk, Ievgen, V
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Träkemi och massateknologi.
    Jaworski, Aleksander
    Stockholm Univ, Dept Mat & Environm Chem, Svante Arrhenius Vag 16C, S-10691 Stockholm, Sweden..
    Chen, Jianhong
    Stockholm Univ, Dept Mat & Environm Chem, Svante Arrhenius Vag 16C, S-10691 Stockholm, Sweden..
    Rokicinska, Anna
    Stockholm Univ, Dept Mat & Environm Chem, Svante Arrhenius Vag 16C, S-10691 Stockholm, Sweden..
    Lindström, Mikael
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Kustrowski, Piotr
    Jagiellonian Univ, Fac Chem, Gronostajowa 2, PL-30387 Krakow, Poland..
    Sevastyanova, Olena
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. Jagiellonian Univ, Fac Chem, Gronostajowa 2, PL-30387 Krakow, Poland..
    Slabon, Adam
    Stockholm Univ, Dept Mat & Environm Chem, Svante Arrhenius Vag 16C, S-10691 Stockholm, Sweden..
    LignoPhot: Conversion of hydrolysis lignin into the photoactive hybrid lignin/Bi4O5Br2/BiOBr composite for simultaneous dyes oxidation and Co2+ and Ni2+ recycling2021Inngår i: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 279, artikkel-id 130538Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Valorization of lignin is still an open question and lignin has therefore remained an underutilized biomaterial. This situation is even more pronounced for hydrolysis lignin, which is characterized by a highly condensed and excessively cross-linked structure. We demonstrate the synthesis of photoactive lignin/Bi4O5Br2/BiOBr bio-inorganic composites consisting of a lignin substrate that is coated by semiconducting nanosheets. The XPS analysis reveals that growing these nanosheets on lignin instead on cellulose prevents the formation of Bi5+ ions at the surface region, yielding thus a modified hetero-junction Bi4O5Br2/BiOBr. The material contains 18.9% of Bi4O5Br2/BiOBr and is effective for the photocatalytic degradation of cationic methylene blue (MB) and zwitterionic rhodamine B (RhB) dyes under light irradiation. Lignin/Bi4O5Br2/BiOBr decreases the dye concentration from 80 mg L-1 to 12.3 mg L-1 for RhB (85%) and from 80 mg L-1 to 4.4 mg L-1 for MB (95%). Complementary to the dye degradation, the lignin as a main component of the composite, was found to be efficient and rapid biosorbent for nickel, lead, and cobalt ions. The low cost, stability and ability to simultaneously photo-oxidize organic dyes and adsorb metal ions, make the photoactive lignin/Bi4O5Br2/BiOBr composite a prospective material for textile wastewaters remediation and metal ions recycling.

  • 41.
    Budnyak, Tetyana M.
    et al.
    Stockholm Univ, Dept Mat & Environm Chem, S-10691 Stockholm, Sweden..
    Piatek, Jeddrzej
    Stockholm Univ, Dept Mat & Environm Chem, S-10691 Stockholm, Sweden..
    Pylypchuk, Ievgen, V
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Träkemi och massateknologi.
    Klimpel, Matthias
    Stockholm Univ, Dept Mat & Environm Chem, S-10691 Stockholm, Sweden..
    Sevastyanova, Olena
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Lindström, Mikael
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Gun'ko, Volodymyr M.
    Natl Acad Sci Ukraine, Chuiko Inst Surface Chem, UA-03164 Kiev, Ukraine..
    Slabon, Adam
    Stockholm Univ, Dept Mat & Environm Chem, S-10691 Stockholm, Sweden..
    Membrane-Filtered Kraft Lignin-Silica Hybrids as Bio-Based Sorbents for Cobalt(II) Ion Recycling2020Inngår i: ACS Omega, E-ISSN 2470-1343, Vol. 5, nr 19, s. 10847-10856Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Efficient and sustainable recycling of cobalt(II) is of increasing importance to support technological development in energy storage and electric vehicle industries. A composite material based on membrane-filtered lignin deposited on nanoporous silica microparticles was found to be an effective and sustainable sorbent for cobalt(II) removal. This bio-based sorbent exhibited a high sorption capacity, fast kinetics toward cobalt(II) adsorption, and good reusability. The adsorption capacity was 18 mg Co(II) per gram of dry adsorbent at room temperature (22 degrees C) at near-neutral pH, three times higher than that of the summarized capacity of lignin or silica starting materials. The kinetics study showed that 90 min is sufficient for effective cobalt(II) extraction by the composite sorbent. The pseudo-second-order kinetics and Freundlich isotherm models fitted well with experimentally obtained data and confirmed heterogeneity of adsorption sites. The promising potential of the lignin-silica composites for industrial applications in the cobalt recovering process was confirmed by high values of desorption in mildly acidic solutions.

  • 42.
    Budnyak, Tetyana M.
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Träkemi och massateknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center. Department of Materials and Environmental Chemistry, Stockholm University, Svante Arrhenius väg 16 C, Stockholm, 106 91, Sweden.
    Pylypchuk, Ievgen, V
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Träkemi och massateknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Lindström, Mikael
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Träkemi och massateknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Sevastyanova, Olena
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Träkemi och massateknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Electrostatic Deposition of the Oxidized Kraft Lignin onto the Surface of Aminosilicas: Thermal and Structural Characteristics of Hybrid Materials2019Inngår i: ACS Omega, E-ISSN 2470-1343, Vol. 4, nr 27, s. 22530-22539Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In recent years, functional polymeric compounds have been widely used to modify the silica surface, which allows one to obtain the corresponding organomineral composites for broad application prospects. In this case, lignin-a cross-linked polyphenolic macromolecule-is of great interest according to its valuable properties and possible surplus as a by-product of pulp and paper industry and various biorefinery processes. Hybrid materials based on kraft softwood lignin and silica were obtained via the electrostatic attraction of oxidized lignin to the aminosilica surface with different porosities, which were prepared by the amination of the commercial silica gel with an average pore diameter of 6 nm, and the silica prepared in the lab with the oxidized kraft lignin and lignin-silica samples with an average pore diameter of 38 nm was investigated by physicochemical methods: two-dimensional nuclear magnetic resonance (NMR), P-31 NMR, Fourier transform infrared spectroscopy, thermogravimetric analysis in nitrogen and air atmosphere, scanning electron microscopy, and adsorption methods. After oxidation, the content of carboxylic groups almost doubled in the oxidized lignin, compared to that in the native one (0.74 mmol/g against 0.44 mmol/g, respectively). The lignin content was deposited onto the surface of aminosilica, depending on the porosity of the silica material and on the content of amino groups on its surface, giving lignin-aminosilica with 20% higher lignin content than the lignin-aminosilica gel. Both types of lignin-silica composites demonstrate a high sorptive capacity toward crystal violet dye. The suggested approach is an easy and low-cost way of synthesis of lignin-silica composites with unique properties. Such composites have a great potential for use as adsorbents in wastewater treatment processes.

  • 43. Börjesson, L.
    et al.
    L, KAELLEN
    C, LINDGREN
    Mikael, Lindström
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Green liquor clarification method for cellulose pulp production, involves using filtering layer which is made of membrane material with pores having predetermined pore size.2009Patent (Annet (populærvitenskap, debatt, mm))
    Abstract [en]

    NOVELTY - The green liquor clarification method involves filtering of flowing suspension containing solids and bringing in contact with a first filter unit (4). The filter unit consists of filter elements (12) with filter bodies having filter channels. A part of the suspension is forced to pass through the filtering layer to forming a filtrate while the solids substantially remain in a residual part of the suspension forming a slurry. The filtering layer is made of a membrane material with pores having a pore size of 0.1-10 micrometer (um), more preferred 0.1-5 um and most preferred 0.2-1.0 um. USE - Green liquor clarification method for cellulose pulp production. ADVANTAGE - Provides a filtering process which is a continuous process with no build up of a filter cake and is very effective in leading to a very high separation degree of dregs which is up to almost 100 percent and the filtrated green liquor is almost free from slurry. Characteristic green color of the green liquor is removed with the dregs which simplifies the identification both of disturbances in the filtration process and in the recovery flimace under normal operating conditions. Investment costs for the cross-flow filtration equipment is very minimal. The space required is much smaller than the space required for the sedimentation tanks. Minimizes oxidation of the valuable sulfide content of the green liquor since there is no contact with the surrounding air, nor is pressurized air used in the equipment. The closed system with no contact with surrounding air or use of vacuum shows that the temperature of the green liquor is maintained at a high level. The modular design of the filters facilitates an incremental capacity increase with minimal investment cost. Provides a simple system with minimal moving parts so less labor is needed for oversight and maintenance. Provides less lime make-up or decreased content of inerts in the lime at the same make-up rate due to less particles in the green liquor Less dregs carryover improves clarification of white liquor and improves mud dewatering and lower energy consumption. Enables efficient removal of non-process elements for minimum operation cost and low landfill volumes. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for an arrangement for green liquor clarification. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic of an arrangement for cleaning green liquor using cross-flow filtration. First filter unit (4) Filter elements (12) Conduit (21) Tank (40) Collecting tank (42)

  • 44.
    Chen, Lan
    et al.
    Guangxi Univ, Coll Light Ind & Food Engn, Nanning 530004, Peoples R China.;Guangxi Univ, Guangxi Key Lab Clean Pulp & Papermaking & Pollut, Nanning 530004, Peoples R China..
    Wei, Xiaoxiao
    Guangxi Univ, Coll Light Ind & Food Engn, Nanning 530004, Peoples R China.;Guangxi Univ, Guangxi Key Lab Clean Pulp & Papermaking & Pollut, Nanning 530004, Peoples R China..
    Wang, Huan
    Guangxi Univ, Coll Light Ind & Food Engn, Nanning 530004, Peoples R China.;Guangxi Univ, Guangxi Key Lab Clean Pulp & Papermaking & Pollut, Nanning 530004, Peoples R China..
    Yao, Min
    Guangxi Univ, Coll Light Ind & Food Engn, Nanning 530004, Peoples R China.;Guangxi Univ, Guangxi Key Lab Clean Pulp & Papermaking & Pollut, Nanning 530004, Peoples R China..
    Zhang, Liming
    Guangxi Univ, Coll Light Ind & Food Engn, Nanning 530004, Peoples R China.;Guangxi Univ, Guangxi Key Lab Clean Pulp & Papermaking & Pollut, Nanning 530004, Peoples R China..
    Gellerstedt, Göran
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Lindström, Mikael
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Ek, Monica
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Wang, Shuangfei
    Guangxi Univ, Coll Light Ind & Food Engn, Nanning 530004, Peoples R China.;Guangxi Univ, Guangxi Key Lab Clean Pulp & Papermaking & Pollut, Nanning 530004, Peoples R China..
    Min, Douyong
    Guangxi Univ, Coll Light Ind & Food Engn, Nanning 530004, Peoples R China.;Guangxi Univ, Guangxi Key Lab Clean Pulp & Papermaking & Pollut, Nanning 530004, Peoples R China..
    A modified ionization difference UV-vis method for fast quantitation of guaiacyl-type phenolic hydroxyl groups in lignin2022Inngår i: International Journal of Biological Macromolecules, ISSN 0141-8130, E-ISSN 1879-0003, Vol. 201, s. 330-337Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    An ionization difference UV-Vis method (Delta epsilon-spectrum method) is the most potentially simple method for fast quantitation of phenolic hydroxyl groups (ph-OH) in lignin. However, the underestimated results were calculated from the conventional Delta epsilon-spectrum method using one- or two-point wavelengths measurement. In this study, a modified Delta epsilon-spectrum method using multi-point wavelengths measurement was developed and the negative absorbance was also considered. Four main typical lignin models, e.g. vanilla alcohol, 5-5 biphenyl, stilbenoid and vanillin, were applied as the guaiacyl-type (G-type) phenolic models for the determination of ph-OH by the modified Delta epsilon-spectrum method. The 2-methoxyethanol/water/acetic acid = 8/2/0.2 (V/V/V) was used as the acidic solvent system and the 2-methoxyethanol/0.2 M NaOH solution = 1/9 (V/V) was used as the alkaline solvent system. The ph-OH contents in the spruce milled wood lignin (SMWL) and the spruce Kraft lignin (SKL) were respectively quantified by the modified Delta epsilon-spectrum method as 1.078 and 4.348 mmol/g, which were comparable to the counterparts determined by P-31 Nuclear Magnetic Resonance Spectroscopy (P-31 NMR). The results revealed that the modified Delta epsilon-spectrum method can provide more accurate and reliable results compared to the conventional method.

  • 45. Christiernin, M.
    et al.
    Henriksson, Gunnar
    KTH, Tidigare Institutioner (före 2005), Pappers- och massateknik.
    Lindström, Mikael
    KTH, Tidigare Institutioner (före 2005), Fiber- och polymerteknologi.
    Brumer, Harry
    KTH, Tidigare Institutioner (före 2005), Bioteknologi.
    Teeri, Tuula T.
    KTH, Tidigare Institutioner (före 2005), Bioteknologi.
    Lindström, T.
    Laine, J.
    The effects of xyloglucan on the properties of paper made from bleached kraft pulp2003Inngår i: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 18, nr 2, s. 182-187Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Xyloglucan was adsorbed onto bleached soft-wood kraft pulp followed by preparation and analysis of handsheets with respect to sheet formation as well as sheet mechanical and optical properties. Adsorption of xyloglucan was found to be slow. After more than 20 hrs adsorption, equilibrium had not been reached. The amount of xyloglucan adsorbed increased with beating, but neither the rate of adsorption nor the quantity adsorbed was significantly affected by temperature. Xyloglucan was found to be practically irreversibly adsorbed onto the fibres and the effects of xyloglucan on paper sheet properties were investigated after thorough washing of the pulp. The adsorption characteristics of xyloglucan confirm observations by other authors on other cellulose substrates. Tensile index values for handsheets formed with the xyloglucan-containing pulps were higher than those measured for control pulps with a comparable beating degree. The light scattering coefficient was, however, not affected by xyloglucan adsorption. Hence, the increase in tensile strength is attributed to an increased relative bond strength between the fibres. Tensile strength versus tear strength relationship was similar for pulps with and without xyloglucan, but water retention value and dewatering resistance were lower for the xyloglucan treated pulps than for the reference pulps at the same tensile strength. In addition, formation was improved for pulps with adsorbed xyloglucan. The conclusion is that xyloglucan is a promising wet end additive that decreases the necessity for beating of the pulp and improves the formation of paper.

  • 46. Dahllöf, Håkan
    et al.
    Nilsson, Erik
    Lindström, Mikael
    Kvaerner Pulping AB.
    An oxygen delignification study concerning storage of unwashed SW oxygen1998Patent (Annet (populærvitenskap, debatt, mm))
  • 47.
    Danielsson, Sverker
    et al.
    KTH.
    Brännvall, Elisabet
    KTH, Tidigare Institutioner (före 2005), Fiber- och polymerteknologi.
    Lindström, Mikael
    KTH, Tidigare Institutioner (före 2005), Fiber- och polymerteknologi.
    Xylan as a surface modifying agent in the kraft cook2006Inngår i: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 231Artikkel i tidsskrift (Annet vitenskapelig)
  • 48.
    Danielsson, Sverker
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Jacobs, A.
    Lindström, Mikael E.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Topochemical modification of fibres during kraft pulping2005Inngår i: Appita Annu. Conf., 2005, s. 155-160Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Xylan dissolution, degradation and redeposition in the birch kraft cook have been examined. The molecular weight of the dissolved xylan was determined through gel permeation chromatography and the loss in molecular weight could be correlated to the amount of degraded xylan in the initial parts of the cook. This indicates that peeling is the only significant xylan degradation reaction early in the cook. Two different birch black liquors containing xylan with the molecular weight of 12.200 g/mol and 5.950 g/mol respectively, were added to softwood kraft cooks in order to determine the effect on pulp strength properties by birch xylan. The results show an increase in both tensile strength and tensile stiffness. The magnitude of the strength increase was affected very much by the molecular weight of xylan. High molecular weight xylan addition increased the tensile strength with more than 10% measured at 1000 PFI revolutions. The tensile stiffness was also increased by xylan addition, high molecular weight to a larger extent than low molecular weight.

  • 49.
    Danielsson, Sverker
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Träkemi och massateknologi.
    Josefsson, Peter
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Träkemi och massateknologi.
    Lindström, Mikael
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Träkemi och massateknologi.
    Adsorption of hardwood black liquor xylan on celluloseManuskript (Annet vitenskapelig)
  • 50.
    Danielsson, Sverker
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Träkemi och massateknologi.
    Kisara, Koki
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Träkemi och massateknologi.
    Lindström, Mikael
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Träkemi och massateknologi.
    Kinetic study of Hexenuronic and Methylglucuronic acid reactions in pulp and in dissolved xylan during kraft pulping of hardwood2006Inngår i: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 45, nr 7, s. 2174-2178Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    During kraft pulping, the side group in the xylan backbone, 4-O-methyl-D-glucuronic acid, is partly converted to hexenuronic acid. Simultaneously, degradation reactions of these side groups take place. The rates of these reactions were studied during the kraft pulping of hardwood and were shown to be strongly affected by the location of the x Ian; dissolved xylan had markedly higher methylglucuronic acid and hexenuronic acid contents than pulp xylan did. The degree of substitution of methyl-lucuronic acid in dissolved xylan was found to be higher at reduced cooking temperatures; no such change was seen for pulp xylan. A kinetic model was developed that included the energies of activation for formation (129 U/mol) and degradation (143 U/mol) of hexenuronic acid and dearadation (141 kJ/mol) of methylglucuronic acid and bulk delignification (118 kJ/mol, in accordance with earlier studies). Decreased cooking temperatures thus increase the number of acidic charged groups in the pulp and in dissolved xylan.

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