Water dynamics in dilute nanofibrillar cellulose systems
Time: Thu 2026-06-04 10.00
Location: D3, Lindstedtsvägen 5, Stockholm
Video link: https://kth-se.zoom.us/j/62932453300
Language: English
Subject area: Fibre and Polymer Science
Doctoral student: Hanno Holzinger , Fiberprocesser
Opponent: Professor Sebastian Meier, Technical University of Denmark, Department of Chemistry
Supervisor: Professor Daniel Söderberg, Wallenberg Wood Science Center, Teknisk mekanik, Fiberprocesser; Doktor Anastasia Riazanova, Wallenberg Wood Science Center, Fiberprocesser
QC 2026-05-07
Embargo t.o.m. 2027-06-04 godkänt av skolchef Amelie Eriksson Karlström via e-post 2026-05-05.
Abstract
Water plays a fundamental role in governing the structure and transport in aqueous soft matter systems, yet its behaviour in complex nanoscale environments remains insufficiently understood. This thesis investigates the self-diffusion of water in cellulose nanofibre (CNF) networks to elucidate the interplay between nanoscale structure, interparticle interactions, and transport properties. Advanced characterization techniques and modelling approaches across atomistic and coarse-grained scales were employed, including pulsed gradient spin-echo nuclear magnetic resonance (PGSE NMR) spectroscopy to quantify water self-diffusion, combined with small-angle and quasielastic neutron scattering (SANS/QENS) to probe network structure and nanofibre dynamics, providing mechanistic insight into the coupled dynamics of fibres and water across multiple length and time scales. The results show that even at low CNF concentrations, water diffusion is reduced beyond simple excluded volume effects, arising from the combined influence of interfacial hydration layering and the dynamic, semi-flexible nature of the nanofibres. Across the sol–gel transition, fibre dynamics become less dominant, while solvated ions and ion-specific interactions increasingly govern both water diffusivity and network structure. In hybrid systems, transport properties can be tuned through strong local interactions between components. Overall, this work establishes a mechanistic framework linking nanoscale interactions, network structure, and transport phenomena in cellulose nanofibre systems. These insights provide a basis for the design of advanced nanocellulose-based materials with tailored transport properties for applications in filtration, biomedicine, and sustainable material development.