Towards tailored hierarchical structures in starch-based cellulose nanocomposite foams prepared by freeze-drying
(English)Manuscript (Other academic)
The properties of nanocomposite foams depend both on cell wall composition and cell structure. In order to fully realize the potential of these materials, both cell wall composition and cell structure must be controlled and tailored. The effect of freezing and freeze-drying temperature on cell structure in nanocomposite foams based on starch and microfibrillated cellulose (MFC) is studied. Freezing experiments are combined with DSC and NMR-analysis of bound water content in order to determine a suitable freeze-drying temperature. The freeze-drying temperature is critical in order to avoid cell structure collapse, as found from cell structure studies by FE-SEM microscopy. Based on this, a foam with mixed open and closed cell structures and as much as 70% MFC in the cell wall was successfully prepared. The study clarifies the interdependence of how the starch-MFC-water suspension composition, in combination with freezing and freeze-drying temperature, will control cell structure of the foams.
IdentifiersURN: urn:nbn:se:kth:diva-9654OAI: oai:DiVA.org:kth-9654DiVA: diva2:126835
QC 201009132008-11-262008-11-242010-09-13Bibliographically approved