In Situ Modification of Regenerated Cellulose Beads: Creating All-Cellulose Composites
Katarzyna Mystek, Michael S. Reid, Per A. Larsson, Lars Wågberg
Abstract
Developing more sustainable products requires innovative ways to utilize and modify renewable resources. Here, a simple one-step in situ modification of regenerated cellulose beads using cellulose nanocrystals (CNC) and dropwise precipitation of cellulose/N,N-dimethylacetamide and lithium chloride (DMAc/LiCl) solution is presented. A more condensed internal structure and increased surface roughness were observed when higher CNC concentrations were used in the precipitation media. Incorporation of CNCs significantly reduces the water holding capacity of the beads and simultaneously impacts the kinetics of drying. Beads modified using the highest CNC concentration (0.5 wt %) exhibited a reduction in the Young modulus by more than 20% and an increase in compressibility to failure by 10% compared with native beads. Overall, inclusion of nanoparticles during bead formation is a simple method that can tune the mechanical, structural, and swelling/drying behavior of cellulose beads and broaden their potential for different end-use applications such as separations and controlled release.