One major route to high performance cellulose based materials is through control of structure at the nanoscale. This applies to a wide variety of applications such as gels, dispersions, composites, films, emulsions. Here we take a multidisciplinary approach to understanding the self assembly of nanocellulose using theory, advanced measurement, and functional studies.
The self assembled structures of cellulose have a major effect on functional properties. This has been demonstrated in several studies, but still we understand the self assembly process only poorly. To gain a deeper understanding we will combine theoretical models on rheological properties together with 3-dimensional imaging of structures, and a physical experimental model for achieving structure.
We were able to study the orientation of components of layered structures with our new polarization-sensitive optical coherence tomographyt (PS-OCT) setup. Its advantage over traditional polarization tools is that it can be used to measure not only average over the studied sample but also local polarization.
PS-OCT has potential as a light-weight online measurement tool, which can be used to observe the local orientation of elongated particles during processing, which is useful when developing novel flow geometries e.g. for 3D printing.
The new method could allow faster adaptation of new fiber-based materials to e.g. additive manufacturing.
Jäsberg, A., Puisto, A., Leppänen, I., Koponen, A. I., and Alava, M. J. Online detection of orientation of cellulose nanocrystals in a capillary flow with polarization-sensitive optical coherence tomography. Cellulose, 30, 3539–3550, 2023. https://doi.org/10.1007/s10570-023-05072-4
Arola, S., Kou, Z., Rooijakkers, B. J. M., Velagapudi, R., Sammalkorpi, M., & Linder, M. B. (2022). On the mechanism for the highly sensitive response of cellulose nanofiber hydrogels to the presence of ionic solutes. Cellulose, 29(11), 6109-6121. https://doi.org/10.1007/s10570-022-04664-w