Ice templated xylan-nanocrystalline cellulose aero/hydrogels

Other conference contribution, 2012

In the current trend for a more effective utilization of biomass, increased attention has been focused to the engineered exploitation of xylans as biopolymer resources in the development of new materials. The xylan backbone has an affinity to cellulose and will adsorb irreversibly on cellulosic surfaces, an inherent property that provides great opportunities for the use of xylan in cellulose-based composites. This paper demonstrates how foams of xylan and nanocrystalline cellulose can be formed by using a freeze-casting technique, i.e. templating of porous structures by solidification of a solvent. Effects of xylan molecular structure and solidification conditions on pore morphology and xylan ultrastructure are evaluated and different ways to stabilize the formed structures are presented. Furthermore, it is demonstrated how crosslinking during the freeze-casting process enables production of nanoreinforced hydrogels with tailored porous structures.