1.5 Time-resolved inertial and ionic behavior of cellulose nanoparticles
- Jonas Tejbo
- PhD student,
- KTH
- Co-author(s): Tomas Rosén
- Supervisor (PhD-students/postdocs): Tomas Rosén
- Cellulose nanocrystals (CNCs), and nanofibrils (CNFs) are abundant bio-materials sourced from wood. They differ in average particle size and CNCs form glass-like dispersions and CNFs act effectively as stabilizers for low-weight water gels. These materials when mixed with a salt or acid form stable gels, branching into differing applications. Their inertial flow behavior are less well studied, and their ionic interactions are mostly considered purely in gel form, not an aligned filament spinning process. We intend to show that their difference in structure and degree of gelation during flow is a significant part of the resulting material performance. We studied the flow of CNCs and CNFs at synchrotron facilities (ESRF, MAXIV) using a shear free mixing setup via small angle x-ray scattering (SAXS), both to identify their inertial flows, and their change in behavior following gelation via NaCl ions. CNCs, at a higher weight percentage achieved higher alignment overall, but lost it with gelation as its tactoids were screened by the Na+ ions. For CNFs, the gelation solidified the fibrous structure set in place by admitting Na+ into its structure, and maintained a stable alignment in ionic and non-ionic cases. Our results shows how similar cellulosic materials can have very different ionic interactions. We intend this work to be useful for those who want a clear look into the actual formation of high-performance cellulose materials, helping to adapt them to practical uses and inspire the study of novel CNC and CNF studies.
- Time of presentation: 10.50