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
Structural changes during swelling of highly charged cellulose fibres
KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.ORCID iD: 0000-0001-6732-2571
KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center. Innventia AB, Sweden.ORCID iD: 0000-0001-9176-7116
KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Fibre Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.ORCID iD: 0000-0001-8622-0386
2015 (English)In: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 22, no 5, 2943-2953 p.Article in journal (Refereed) Published
Abstract [en]

Structural changes of fibrils and fibril aggregates in the fibre wall were studied after oxidation of the cellulose by 2,2,6,6-tetramethyl-1-piperidinyloxy to high charge densities (highest charge density: 1300 mu eq/g). The increase in pore volume was measured by mini-WRV at two different pH levels, and the supramolecular structure in the fibre wall in terms of aggregate size, specific surface area and average pore size was measured by solid state NMR, DVS desorption and BET N-2 gas adsorption. A structural change in the arrangement of the fibrils inside the fibril aggregates was observed although the oxidation did not lead to a complete liberation of individual fibrils, i.e. they still exist as an aggregated structure after oxidation. Theoretical estimates suggest that the electrostatic repulsion energy connected with the increase in surface charge of the fibrils can be sufficient to gradually separate the fibrils enough to expose all fibril surfaces to oxidation chemicals.

Place, publisher, year, edition, pages
2015. Vol. 22, no 5, 2943-2953 p.
National Category
Polymer Technologies Paper, Pulp and Fiber Technology
Identifiers
URN: urn:nbn:se:kth:diva-155537DOI: 10.1007/s10570-015-0701-4ISI: 000361002000007Scopus ID: 2-s2.0-84941416963OAI: oai:DiVA.org:kth-155537DiVA: diva2:761583
Note

Updated from manuscript to article.

QC 20151009

Available from: 2014-11-07 Created: 2014-11-07 Last updated: 2017-12-05Bibliographically approved
In thesis
1. Preparation and characterization of nanoporous cellulose fibres and their use in new material concepts
Open this publication in new window or tab >>Preparation and characterization of nanoporous cellulose fibres and their use in new material concepts
2014 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The overall objective of the work in this thesis is to better utilize the non-collapsed structure of the delignified wood-fibre cell wall in the preparation of new types of materials.

In order to utilize the fibres in new materials, it is crucial to have a well-defined starting material and to know how it reacts to certain treatments of the fibres. A new robust method for measuring the average pore size of water-swollen fibres-rich in cellulose is presented. This method is based on solid-state NMR, which measures the specific surface area [m2/g] of water-swollen samples, and the fibre saturation point (FSP) method, which measures the pore volume [water mass/solid mass] of a water swollen sample. These results can be combined since they are both recorded on water-swollen fibres in the presence of excess water and neither is based on any assumption of any particular pore geometry. Delignifed wood fibres (chemical pulp fibres) have an open fibrillar structure, with approximately 20 nm thick fibril aggregates arranged in a porous structure with a specific surface area of 150 m2/g. This open structure was preserved in the dry state by a liquid-exchange procedure followed by careful drying in argon gas. The dry structure had a specific surface area of 130 m2/g, which implies that the porous structure was preserved in the dry state.

New fibre-basedmaterials were prepared by two different strategies.

The first strategy was to utilize the open nanoporous fibre wall structure for the preparation of nanocomposites. The nanoporous structure was used as a scaffold, allowing monomers to impregnate the structure and to be in-situ polymerized inside the fibre wall pores. Poly(methyl methacrylate) (PMMA) and poly(butylacrylate) (PBA) were synthesized inside the dry nanoporous fibre wall structure, and an epoxy resin was cured in never-dried fibres oxidized to different degrees by TEMPO. The composites prepared thus have a mixture of fibril aggregates and a polymer matrix inside the fibre wall. The structure and performance of the composite materials were evaluated both by high resolution microscopy and mechanically. Characterization of the composite showed that the polymer matrix was successfully formed inside the fibre wall pores. The structural changes caused by oxidation were preserved and utilized for the composite with the epoxy matrix. By tailoring the supramolecular structure of fibres in their water-swollen state, it was hence indeed possible to control the mechanical performance of the nanostructured fibre composites.

The secondbstrategy used to prepare composites was to improve the thermoplastic properties of paper by adding polylactic acid (PLA) latex during the preparation of fibrebsheets. By the addition of PLA-latex, it was possible to form double curved sheets with a nominal strain at break of 21%.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2014. 57 p.
Series
TRITA-CHE-Report, ISSN 1654-1081 ; 2014:41
National Category
Paper, Pulp and Fiber Technology Composite Science and Engineering
Research subject
Fibre and Polymer Science
Identifiers
urn:nbn:se:kth:diva-155530 (URN)978-91-7595-290-1 (ISBN)
Public defence
2014-11-28, F3, Lindstedtsvägen 26, KTH, Stockholm, 10:00 (English)
Opponent
Supervisors
Funder
Knut and Alice Wallenberg Foundation
Note

QC 20141107

Available from: 2014-11-07 Created: 2014-11-06 Last updated: 2014-11-07Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textScopus

Authority records BETA

Wohlert, JakobLarsson, Per TomasWågberg, Lars

Search in DiVA

By author/editor
Sjöstedt, AnnaWohlert, JakobLarsson, Per TomasWågberg, Lars
By organisation
Fibre and Polymer TechnologyWallenberg Wood Science CenterFibre Technology
In the same journal
Cellulose (London)
Polymer TechnologiesPaper, Pulp and Fiber Technology

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 320 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