Lightweight and strong cellulose materials made from aqueous foams stabilized by NanoFibrillated Cellulose (NFC)
(English)Manuscript (preprint) (Other academic)
A novel, lightweight and strong porous cellulose material has been prepared by drying aqueous foams stabilized with surface-modified NanoFibrillated Cellulose (NFC). This material differs from other particle stabilized foams in that we use renewable cellulose as stabilizing particle. Confocal microscopy and high speed video imaging show that the long-term stability of the wet foams can be attributed to the octylamine-coated, rod-shaped NFC nanoparticles residing at the air-liquid interface which prevent the air bubbles from collapsing or coalescing. This can be achieved at solids content around 1 % by weight. Careful removal of the water results in a cellulose-based material with a porosity of 98 % and a density of 30 mg cm-3. These porous cellulose materials have a higher Young’s modulus than other cellulose materials made by freeze drying and a compressive energy absorption of 56 kJ m-3 at 80 % strain. Measurement with the aid of an autoporosimeter revealed that most pores are in the range of 300 to 500 μm.
IdentifiersURN: urn:nbn:se:kth:diva-104223OAI: oai:DiVA.org:kth-104223DiVA: diva2:563506
QS 20122012-10-302012-10-302012-11-07Bibliographically approved