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Ottesen, V., Larsson, P. T., Chinga-Carrasco, G., Syverud, K. & Gregersen, O. W. (2019). Mechanical properties of cellulose nanofibril films: effects of crystallinity and its modification by treatment with liquid anhydrous ammonia. Cellulose (London), 26(11), 6615-6627
Open this publication in new window or tab >>Mechanical properties of cellulose nanofibril films: effects of crystallinity and its modification by treatment with liquid anhydrous ammonia
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2019 (English)In: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 26, no 11, p. 6615-6627Article in journal (Refereed) Published
Abstract [en]

The influence of cellulose crystallinity on mechanical properties of cellulose nano-fibrils (CNF) was investigated. Degree of crystallinity (DoC) was modified using liquid anhydrous ammonia. Such treatment changes crystal allomorph from cellulose I to cellulose III, a change which was reversed by subsequent boiling in water. DoC was measured using solid state nuclear magnetic resonance (NMR). Crystalline index (CI) was also measured using wide angle X-ray scattering (WAXS). Cotton linters were used as the raw material. The cotton linter was ammonia treated prior to fibrillation. Reduced DoC is seen to associate with an increased yield point and decreased Young modulus. Young modulus is here defined as the maximal slope of the stress-strain curves. The association between DoC and Young modulus or DoC and yield point are both statistically significant. We cannot conclude there has been an effect on strainability. While mechanical properties were affected, we found no indication that ammonia treatment affected degree of fibrillation. CNF was also studied in air and liquid using atomic force microscopy (AFM). Swelling of the nanofibers was observed, with a mean diameter increase of 48.9%.

Place, publisher, year, edition, pages
SPRINGER, 2019
Keywords
Degree of crystallinity, Mechanical properties, Swelling, Cellulose nanofibrils
National Category
Polymer Technologies
Identifiers
urn:nbn:se:kth:diva-255426 (URN)10.1007/s10570-019-02546-2 (DOI)000473598400013 ()2-s2.0-85067190175 (Scopus ID)
Note

QC 20190815

Available from: 2019-08-15 Created: 2019-08-15 Last updated: 2019-08-19Bibliographically approved
Larsson, P. T., Karlsson, P. & Wågberg, L. (2019). Swelling behavior of cellulose rich materials in water. Paper presented at National Meeting of the American-Chemical-Society (ACS), MAR 31-APR 04, 2019, Orlando, FL. Abstracts of Papers of the American Chemical Society, 257
Open this publication in new window or tab >>Swelling behavior of cellulose rich materials in water
2019 (English)In: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 257Article in journal, Meeting abstract (Other academic) Published
Place, publisher, year, edition, pages
AMER CHEMICAL SOC, 2019
National Category
Paper, Pulp and Fiber Technology
Identifiers
urn:nbn:se:kth:diva-257623 (URN)000478860502433 ()
Conference
National Meeting of the American-Chemical-Society (ACS), MAR 31-APR 04, 2019, Orlando, FL
Note

QC 20190918

Available from: 2019-09-18 Created: 2019-09-18 Last updated: 2019-09-18Bibliographically approved
Karlsson, R.-M. P., Larsson, P. T., Hansson, P. & Wågberg, L. (2019). Thermodynamics of the Water-Retaining Properties of Cellulose-Based Networks. Biomacromolecules, 20(4), 1603-1612
Open this publication in new window or tab >>Thermodynamics of the Water-Retaining Properties of Cellulose-Based Networks
2019 (English)In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 20, no 4, p. 1603-1612Article in journal (Refereed) Published
Abstract [en]

Noncrystalline cellulose-based gel beads were used as a model material to investigate the effect of osmotic stress on a cellulosic network. The gel beads were exposed to osmotic stress by immersion in solutions with different concentrations of high molecular mass dextran and the equilibrium dimensional change of the gel beads was studied using optical microscopy. The volume fraction of cellulose was calculated from the volume of the gel beads in dextran solutions and their dry content and the relation between the cellulose volume fraction and the total osmotic pressure was thus obtained. The results show that the contribution to the osmotic pressure from counterions increases the water-retaining capacity of the beads at high osmotic pressures but also that the main factor controlling the gel bead collapse at high osmotic strains is the resistance to the deformation of the polymer chain network within the beads. Furthermore, the osmotic pressure associated with the deformation of the polymer network, which counteracts the deswelling of the beads, could be fitted to the Wall model indicating that the response of the cellulose polymer networks was independent of the charge of the cellulose. The best fit to the Wall model was obtained when the Flory-Huggins interaction parameter () of the cellulose-water system was set to 0.55-0.60, in agreement with the well-established insolubility of high molecular mass β-(1,4)-d-glucan polymers in water.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2019
National Category
Polymer Chemistry
Research subject
Fibre and Polymer Science
Identifiers
urn:nbn:se:kth:diva-250012 (URN)10.1021/acs.biomac.8b01791 (DOI)000464248300013 ()2-s2.0-85063128803 (Scopus ID)
Note

QC 20190509

Available from: 2019-04-25 Created: 2019-04-25 Last updated: 2019-05-22Bibliographically approved
Larsson, P. T., Karlsson, P. & Wågberg, L. (2019). Why haven't plastic packaging been replaced by cellulose?. Paper presented at National Meeting of the American-Chemical-Society (ACS), MAR 31-APR 04, 2019, Orlando, FL. Abstracts of Papers of the American Chemical Society, 257
Open this publication in new window or tab >>Why haven't plastic packaging been replaced by cellulose?
2019 (English)In: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 257Article in journal, Meeting abstract (Other academic) Published
Place, publisher, year, edition, pages
AMER CHEMICAL SOC, 2019
National Category
Paper, Pulp and Fiber Technology
Identifiers
urn:nbn:se:kth:diva-257624 (URN)000478860502743 ()
Conference
National Meeting of the American-Chemical-Society (ACS), MAR 31-APR 04, 2019, Orlando, FL
Note

QC 20190913

Available from: 2019-09-13 Created: 2019-09-13 Last updated: 2019-09-13Bibliographically approved
Karlsson, R.-M. P., Larsson, P. T., Yu, S., Pendergraph, S. A., Pettersson, T., Hellwig, J. & Wågberg, L. (2018). Carbohydrate gel beads as model probes for quantifying non-ionic and ionic contributions behind the swelling of delignified plant fibers. Journal of Colloid and Interface Science, 519, 119-129
Open this publication in new window or tab >>Carbohydrate gel beads as model probes for quantifying non-ionic and ionic contributions behind the swelling of delignified plant fibers
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2018 (English)In: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 519, p. 119-129Article in journal (Refereed) Published
Abstract [en]

Macroscopic beads of water-based gels consisting of uncharged and partially charged beta-(1,4)-D-glucan polymers were developed to be used as a novel model material for studying the water induced swelling of the delignified plant fiber walls. The gel beads were prepared by drop-wise precipitation of solutions of dissolving grade fibers carboxymethylated to different degrees. The internal structure was analyzed using Solid State Cross-Polarization Magic Angle Spinning Carbon-13 Nuclear Magnetic Resonance and Small Angle X-ray Scattering showing that the internal structure could be considered a homogeneous, non-crystalline and molecularly dispersed polymer network. When beads with different charge densities were equilibrated with aqueous solutions of different ionic strengths and/or pH, the change in water uptake followed the trends expected for weak polyelectrolyte gels and the trends found for cellulose-rich fibers. When dried and subsequently immersed in water the beads also showed an irreversible loss of swelling depending on the charge and type of counter-ion which is commonly also found for cellulose-rich fibers. Taken all these results together it is clear that the model cellulose-based beads constitute an excellent tool for studying the fundamentals of swelling of cellulose rich plant fibers, aiding in the elucidation of the different molecular and supramolecular contributions to the swelling.

Place, publisher, year, edition, pages
Academic Press, 2018
Keywords
Swelling, Water uptake, Hydrogel, Cellulose, Small-angle X-ray scattering, Solid state NMR, Atomic force microscopy
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-226733 (URN)10.1016/j.jcis.2018.02.052 (DOI)000429633500013 ()29486431 (PubMedID)2-s2.0-85042413398 (Scopus ID)
Funder
Knut and Alice Wallenberg Foundation
Note

QC 20180503

Available from: 2018-05-03 Created: 2018-05-03 Last updated: 2019-04-25Bibliographically approved
Mittal, N., Ansari, F., Gowda, K. V., Brouzet, C., Chen, P., Larsson, P. T., . . . Söderberg, D. (2018). Multiscale Control of Nanocellulose Assembly: Transferring Remarkable Nanoscale Fibril Mechanics to Macroscale Fibers. ACS Nano, 12(7), 6378-6388
Open this publication in new window or tab >>Multiscale Control of Nanocellulose Assembly: Transferring Remarkable Nanoscale Fibril Mechanics to Macroscale Fibers
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2018 (English)In: ACS Nano, ISSN 1936-0851, E-ISSN 1936-086X, Vol. 12, no 7, p. 6378-6388Article in journal (Refereed) Published
Abstract [en]

Nanoscale building blocks of many materials exhibit extraordinary mechanical properties due to their defect-free molecular structure. Translation of these high mechanical properties to macroscopic materials represents a difficult materials engineering challenge due to the necessity to organize these building blocks into multiscale patterns and mitigate defects emerging at larger scales. Cellulose nanofibrils (CNFs), the most abundant structural element in living systems, has impressively high strength and stiffness, but natural or artificial cellulose composites are 3-15 times weaker than the CNFs. Here, we report the flow-assisted organization of CNFs into macroscale fibers with nearly perfect unidirectional alignment. Efficient stress transfer from macroscale to individual CNF due to cross-linking and high degree of order enables their Young's modulus to reach up to 86 GPa and a tensile strength of 1.57 GPa, exceeding the mechanical properties of known natural or synthetic biopolymeric materials. The specific strength of our CNF fibers engineered at multiscale also exceeds that of metals, alloys, and glass fibers, enhancing the potential of sustainable lightweight high-performance materials with multiscale self-organization.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2018
Keywords
bio-based materials, selforganization, mechanical properties, microfluidics, cellulose nanofibrils, nanocompositesbio-based materials, selforganization, mechanical properties, microfluidics, cellulose nanofibrils, nanocomposites
National Category
Engineering and Technology
Research subject
Engineering Mechanics; Fibre and Polymer Science; Physics
Identifiers
urn:nbn:se:kth:diva-229288 (URN)10.1021/acsnano.8b01084 (DOI)000440505000004 ()29741364 (PubMedID)2-s2.0-85049865626 (Scopus ID)
Funder
Knut and Alice Wallenberg Foundation
Note

QC 20180608

Available from: 2018-06-01 Created: 2018-06-01 Last updated: 2019-10-16Bibliographically approved
Kaldéus, T., Larsson, P. T., Boujemaoui, A. & Malmström, E. (2018). One-pot preparation of bi-functional cellulose nanofibrils. Cellulose (London), 25(12), 7031-7042
Open this publication in new window or tab >>One-pot preparation of bi-functional cellulose nanofibrils
2018 (English)In: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 25, no 12, p. 7031-7042Article in journal (Refereed) Published
Abstract [en]

Herein, we present a route to obtain bi-functional cellulose nanofibrils (CNF) by a one-pot approach using an already established functionalisation route, carboxymethylation, to which a subsequent functionalisation step, allylation or alkynation, has been added in the same reaction pot, eliminating the need of solvent exchange procedures. The total charge of the fibres and the total surface charge of the nanofibrils were determined by conductometric and polyelectrolyte titration, respectively. Furthermore, the allyl and alkyne functionalised cellulose were reacted with methyl 3-mercaptopropionate and azide-functionalised disperse red, respectively, to estimate the degree of functionalisation. The samples were further assessed by XPS and FT-IR. Physical characteristics were evaluated by CP/MAS C-13-NMR, XRD, AFM and DLS. This new approach of obtaining bi-functionalised CNF allows for a facile and rapid functionalisation of CNF where chemical handles can easily be attached and used for further modification of the fibrils.

Place, publisher, year, edition, pages
SPRINGER, 2018
Keywords
Carboxymethylation, Functionalised cellulose nanofibrils, Allylation, Alkynation
National Category
Paper, Pulp and Fiber Technology
Identifiers
urn:nbn:se:kth:diva-239754 (URN)10.1007/s10570-018-2066-y (DOI)000449946300016 ()2-s2.0-85054565647 (Scopus ID)
Note

QC 20190110

Available from: 2019-01-10 Created: 2019-01-10 Last updated: 2019-02-17Bibliographically approved
Lo Re, G., Spinella, S., Boujemaoui, A., Vilaseca, F., Larsson, P. T., Adås, F. & Berglund, L. (2018). Poly(ε-caprolactone) Biocomposites Based on Acetylated Cellulose Fibers and Wet Compounding for Improved Mechanical Performance. ACS Sustainable Chemistry & Engineering, 5(6), 6753-6760
Open this publication in new window or tab >>Poly(ε-caprolactone) Biocomposites Based on Acetylated Cellulose Fibers and Wet Compounding for Improved Mechanical Performance
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2018 (English)In: ACS Sustainable Chemistry & Engineering, ISSN 2168-0485, Vol. 5, no 6, p. 6753-6760Article in journal, Editorial material (Refereed) Published
Abstract [en]

Poly(epsilon-caprolactone) (PCL) is a ductile thermoplastic, which is biodegradable in the marine environment. Limitations include low strength, petroleum-based origin, and comparably high cost. Cellulose fiber reinforcement is therefore of interest although uniform fiber dispersion is a challenge. In this study, a one-step wet compounding is proposed to validate a sustainable and feasible method to improve the dispersion of the cellulose fibers in hydrophobic polymer matrix as PCL, which showed to be insensitive to the presence of the water during the processing. A comparison between unmodified and acetylated cellulosic wood fibers is made to further assess the net effect of the wet feeding and chemical modification on the biocomposites properties, and the influence of acetylation on fiber structure is reported (ATR-FTIR, XRD). Effects of processing on nano fibrillation, shortening, and dispersion of the cellulose fibers are assessed as well as on PCL molar mass. Mechanical testing, dynamic mechanical thermal analysis, FE-SEM, and X-ray tomography is used to characterize composites. With the addition of 20 wt % cellulosic fibers, the Young's modulus increased from 240 MPa (neat PCL) to 1850 MPa for the biocomposites produced by using the wet feeding strategy, compared to 690 MPa showed for the biocomposites produced using dry feeling. A wet feeding of acetylated cellulosic fibers allowed even a greater increase, with an additional 46% and 248% increase of the ultimate strength and Young's modulus, when compared to wet feeding of the unmodified pulp, respectively.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2018
National Category
Polymer Technologies
Research subject
Chemical Engineering
Identifiers
urn:nbn:se:kth:diva-225425 (URN)10.1021/acssuschemeng.8b00551 (DOI)000431927500117 ()2-s2.0-85046751578 (Scopus ID)
Note

QC 20180531

Available from: 2018-04-04 Created: 2018-04-04 Last updated: 2018-06-04Bibliographically approved
Larsson, P. T., Karlsson, R.-M. P., Westlund, P.-O. & Wågberg, L. (2017). Internal Structure of Isolated Cellulose I Fibril Aggregates in the Water Swollen State. In: Nanocelluloses: Their Preparation, Properties and Applications: . Washington, DC: American Chemical Society (ACS)
Open this publication in new window or tab >>Internal Structure of Isolated Cellulose I Fibril Aggregates in the Water Swollen State
2017 (English)In: Nanocelluloses: Their Preparation, Properties and Applications, Washington, DC: American Chemical Society (ACS), 2017Chapter in book (Refereed)
Abstract [en]

By combining H-2-NMRD and CP/MAS C-13-NMR measurements of water-based cellulose gels and of water swollen pulps it was possible to estimate the nature of the interior structure of cellulose fibril aggregates. A set of samples with high cellulose purity and low charge was used. The interpretation of data was based on a relaxation model describing the exchange dynamics for deuterium exchange between water molecules and cellulose hydroxyl groups. The theoretical model used made it possible to calculate cellulose surface-to-volume ratios (q-values) from both H-2-NMRD and CP/MAS C-13-NMR data. Good consistency between H-2-NMRD and CP/MAS C-13-NMR data was found. In all investigated samples the cellulose fibril aggregates showed a different degree of "openness" interpreted as the presence of interstitial water inside fibril aggregates. One result also showed that an increased degree of fibril aggregate openness results from the TEMPO-oxidation. Common to all samples was that in the water swollen state water molecules could access part of the fibril aggregate interior.

Place, publisher, year, edition, pages
Washington, DC: American Chemical Society (ACS), 2017
Series
ACS Symposium Series
National Category
Polymer Chemistry
Research subject
Fibre and Polymer Science
Identifiers
urn:nbn:se:kth:diva-250010 (URN)000417770800005 ()
Note

QC 20190520

Available from: 2019-04-25 Created: 2019-04-25 Last updated: 2019-05-20Bibliographically approved
Larsson, P. T., Wågberg, L., Westlund, P.-O. & Karlsson, P. (2016). Internal structure of cellulose I fibril aggregates studied by a combination of structure and dynamics measurements. Abstract of Papers of the American Chemical Society, 251
Open this publication in new window or tab >>Internal structure of cellulose I fibril aggregates studied by a combination of structure and dynamics measurements
2016 (English)In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 251Article in journal, Meeting abstract (Other academic) Published
Place, publisher, year, edition, pages
AMER CHEMICAL SOC, 2016
National Category
Organic Chemistry
Identifiers
urn:nbn:se:kth:diva-242692 (URN)000431903802426 ()
Note

QC 20190221

Available from: 2019-02-21 Created: 2019-02-21 Last updated: 2019-02-21Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0001-9176-7116

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