Stabilizing nanocellulose-nonionic surfactant composite foams by delayed Ca-induced gelation

Research output: Contribution to journalArticle

Abstract

Aggregation of dispersed rod-like particles like nanocellulose can improve the strength and rigidity of percolated networks but may also have a detrimental effect on the foamability. However, it should be possible to improve the strength of nanocellulose foams by multivalent ion-induced aggregation if the aggregation occurs after the foam has been formed. Lightweight and highly porous foams based on TEMPO-mediated oxidized cellulose nanofibrils (CNF) were formulated with the addition of a non-ionic surfactant, pluronic P123, and CaCO3 nanoparticles. Foam volume measurements show that addition of the non-ionic surfactant generates wet CNF/P123 foams with a high foamability. Foam bubble size studies show that delayed Ca-induced aggregation of CNF by gluconic acid-triggered dissolution of the CaCO3 nanoparticles significantly improves the long-term stability of the wet composite foams. Drying the Ca-reinforced foam at 60 °C results in a moderate shrinkage and electron microscopy and X-ray tomography studies show that the pores became slightly oblate after drying but the overall microstructure and pore/foam bubble size distribution is preserved after drying. The elastic modulus (0.9-1.4 MPa) of Ca-reinforced composite foams with a density of 9-15 kg/m3 is significantly higher than commercially available polyurethane foams used for thermal insulation.

Details

Authors
  • Korneliya S. Gordeyeva
  • Andreas B. Fall
  • Stephen Hall
  • Bernd Wicklein
  • Lennart Bergström
Organisations
External organisations
  • Stockholm University
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Materials Chemistry

Keywords

  • Foams, Gelation, Multivalent-ion, Nanocellulose, Strength, Surfactant, X-ray tomography
Original languageEnglish
Pages (from-to)44-51
Number of pages8
JournalJournal of Colloid and Interface Science
Volume472
Publication statusPublished - 2016 Jun 15
Publication categoryResearch
Peer-reviewedYes

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