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
Unidirectional Swelling of Dynamic Cellulose Nanofibril Networks: A Platform for Tunable Hydrogels and Aerogels with 3D Shapeability
KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Fibre Technology.ORCID iD: 0000-0003-4388-8970
KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Fibre Technology.
2019 (English)In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 20, no 6, p. 2406-2412Article in journal (Refereed) Published
Abstract [en]

A process has been developed to create self-supporting hydrogels with low solids content (down to 0.5 wt %) and anisotropic aerogels with a low density (down to 5 kg/m(3)) from cellulose nanofibrils (CNFs). The CNF networks were formed by vacuum filtration of dilute dispersions (0.2 wt %) of 90% CNFs and 10% alginate. We call this process "the dynamic CNF network approach" since the solids content of these hydrogels can be tuned in the range of 0.5-3 wt % by reswelling the filter cakes in a medium with a controlled osmotic pressure. These hydrogels are significantly stronger than the 1-2 wt % CNF gels typically used to prepare hydrogels and aerogels because the dynamic CNF networks are formed below their arrested state threshold (ca. 0.5 wt %) and are thus homogeneous. The vacuum filtration leads to a directional reswelling vertical to the plane of the filter cake, and this is crucial in order to turn a two-dimensional (2D) shape, cut from the filter cake, into a 3D hydrogel without distorting the 2D shape. The anisotropic swelling was used to create intricate 3D-shaped hydrogels and solved some of the issues involved in the degassing and molding of high-viscosity CNF gels. Multivalent ions were used to lock the CNF and alginate networks at the desired solids content and 3D shape, and resulted in an increase by an order of magnitude in storage modulus. Moreover, the self-supporting nature of the hydrogels allowed us to freeze-cast them into anisotropic aerogels with the same 3D shape without using any container. The 5 kg/m(3) aerogel had a specific modulus of 43 kN m/kg and an anisotropy index of 12, which are impressive properties in relation to earlier experiences. The process can be used for applications where a precise control of density and shape is critical.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2019. Vol. 20, no 6, p. 2406-2412
National Category
Chemical Sciences
Identifiers
URN: urn:nbn:se:kth:diva-254516DOI: 10.1021/acs.biomac.9b00401ISI: 000471212500023PubMedID: 31050412OAI: oai:DiVA.org:kth-254516DiVA, id: diva2:1334475
Note

QC 20190702

Available from: 2019-07-02 Created: 2019-07-02 Last updated: 2019-07-02Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full textPubMed

Search in DiVA

By author/editor
Benselfelt, TobiasWågberg, Lars
By organisation
Fibre Technology
In the same journal
Biomacromolecules
Chemical Sciences

Search outside of DiVA

GoogleGoogle Scholar

doi
pubmed
urn-nbn

Altmetric score

doi
pubmed
urn-nbn
Total: 173 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