Stabilizing nanocellulose-nonionic surfactant composite foams by delayed Ca-induced gelation
Författare
Summary, in English
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.
Avdelning/ar
Publiceringsår
2016-06-15
Språk
Engelska
Sidor
44-51
Publikation/Tidskrift/Serie
Journal of Colloid and Interface Science
Volym
472
Dokumenttyp
Artikel i tidskrift
Förlag
Elsevier
Ämne
- Materials Chemistry
Nyckelord
- Foams
- Gelation
- Multivalent-ion
- Nanocellulose
- Strength
- Surfactant
- X-ray tomography
Status
Published
ISBN/ISSN/Övrigt
- ISSN: 0021-9797