Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Molecular deformation mechanisms in cellulose allomorphs and the role of hydrogen bonds
KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.ORCID iD: 0000-0002-0889-5940
KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.ORCID iD: 0000-0001-5818-2378
KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.ORCID iD: 0000-0001-6732-2571
(English)Manuscript (preprint) (Other academic)
National Category
Chemical Engineering
Identifiers
URN: urn:nbn:se:kth:diva-166781OAI: oai:DiVA.org:kth-166781DiVA: diva2:812226
Note

QS 2015

Available from: 2015-05-18 Created: 2015-05-18 Last updated: 2015-05-18Bibliographically approved
In thesis
1. Deformation of cellulose allomorphs studied by molecular dynamics
Open this publication in new window or tab >>Deformation of cellulose allomorphs studied by molecular dynamics
2015 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

Cellulose-based materials draw their good mechanical properties from the cellu-lose crystal. Improved understanding of crystal properties could lead to a wider range of applications for cellulose-based materials, Cellulose crystals show high axial Youngs modulus. Cellulose can attain several allomorphic forms which show unique structural arrangements in terms of both intra-molecular and inter-molecular bonding, as well as unit cell parameters and chain packing. Although several studies have confirmed that mechanical tensile properties of cellulose differ between different allomorphic forms, few reports have investigated the deformation mechanisms explaining the differences.In the first part of this thesis, the tensile elastic Youngs modulus of cellulose allo-morphs Iβ, II and III I were calculated under uniform conditions using Molecular Dynamics simulation techniques. As expected, a difference in modulus valuesc ould be observed, and the cooperative nature of energy contributions to crys-tal modulus is apparent. The allomorphs also show large differences in terms of how contributions to elastic energy are distributed between covalent bonds,angles, dihedrals, electrostatic forces, dispersion and steric forces.In the second part of this thesis, the cellulose Iβ and II allomorphs were sub-jected to a more detailed structural study. The purpose was to clarify how the deformation of the central glucosidic linkage between the monomer units depends on the hydrogen-bonding structures. This was carried out by studying simulated vibrational spectra and local deformations in the crystals.The results presented in this thesis confirm the differences in the tensile elastic properties of these cellulose allomorphs. These differences can in part be explained by the different intra-molecular hydrogen bonding patterns between allomorphs. Deformation mechanisms are discussed. The results are in supportof the so called ”leverage effect” proposed in the literature. The present analysis shows significant differences in details of deformation mechanisms compared with previous simpler analyses.

Place, publisher, year, edition, pages
KTH Royal Institute of Technology, 2015. 29 p.
Series
TRITA-CHE-Report, ISSN 1654-1081 ; 2015:20
Keyword
Cellulose, Polymer, Molecular Dynamics
National Category
Polymer Technologies
Research subject
Fibre and Polymer Science
Identifiers
urn:nbn:se:kth:diva-166654 (URN)978-91-7595-541-4 (ISBN)
Presentation
2015-05-28, D3, Lindstedtsvägen 5, Stockholm, 10:00 (English)
Opponent
Supervisors
Funder
Swedish Research Council, 63625
Note

QC 20150518

Available from: 2015-05-18 Created: 2015-05-13 Last updated: 2015-05-18Bibliographically approved

Open Access in DiVA

No full text

Authority records BETA

Djahedi, CyrusBerglund, Lars A.Wohlert, Jakob

Search in DiVA

By author/editor
Djahedi, CyrusBerglund, Lars A.Wohlert, Jakob
By organisation
Fibre and Polymer Technology
Chemical Engineering

Search outside of DiVA

GoogleGoogle Scholar

urn-nbn

Altmetric score

urn-nbn
Total: 43 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf