Moisture-Dependent Vibrational Dynamics and Phonon Transport in Nanocellulose MaterialsShow others and affiliations
2024 (English)In: Advanced Materials, ISSN 0935-9648, E-ISSN 1521-4095Article in journal (Refereed) Epub ahead of print
Abstract [en]
Superinsulating nanofibrillar cellulose foams have the potential to replace fossil-based insulating materials, but the development is hampered by the moisture-dependent heat transport and the lack of direct measurements of phonon transport. Here, inelastic neutron scattering is used together with wide angle X-ray scattering (WAXS) and small angle neutron scattering to relate the moisture-dependent structural modifications to the vibrational dynamics and phonon transport and scattering of cellulose nanofibrils from wood and tunicate, and wood cellulose nanocrystals (W-CNC). The moisture interacted primarily with the disordered regions in nanocellulose, and WAXS showed that the crystallinity and coherence length increased as the moisture content increased. The phonon population derived from directional-dependent phonon density of states (GDOS) increased along the cellulose chains in W-CNC between 5 and 8 wt% D2O, while the phonon population perpendicular to the chains remained relatively unaffected, suggesting that the effect of increased crystallinity and coherence length on phonon transport is compensated by the moisture-induced swelling of the foam walls. Frequency scaling in the low-energy GDOS showed that materials based on hygroscopic and semicrystalline nanocellulose falls in between the predicted behavior for solids and liquids. Phonon-engineering of hygroscopic biopolymer-based insulation materials is promoted by the insights on the moisture-dependent phonon transport.
Place, publisher, year, edition, pages
John Wiley and Sons Inc , 2024.
Keywords [en]
Cellulose nanocrystals; Crystallinity; Foams; Insulation; Liquid insulating materials; Moisture determination; Nanocrystalline materials; Nanofibers; Nanofiltration membranes; Swelling; Wood; X ray scattering; %moisture; Coherence lengths; Cristallinity; Heat transport; Inelastic neutrons; Nano-cellulose; Nanofibrillar cellulose; Phonon transport; Vibrational dynamics; Wide angle X-ray scattering; Inelastic neutron scattering
National Category
Materials Engineering
Identifiers
URN: urn:nbn:se:ri:diva-76457DOI: 10.1002/adma.202415725Scopus ID: 2-s2.0-85212270632OAI: oai:DiVA.org:ri-76457DiVA, id: diva2:1932425
Note
A.Å. and L.B. acknowledge the Swedish Foundation for Strategic Research (SSF)-funded graduate school SwedNess (grant GSn15-008) for financial support. E.N. acknowledges financial support from the SSF-Swedness PostDoc grant (SNP21-0004) and the Foundation Blanceflor 2024 fellow scholarship. L.B. gratefully acknowledge support from the Wallenberg Initiative Materials Science for Sustainability (WISE) funded by the Knut and Alice Wallenberg Foundation (KAW). K.U. thanks Sakura Inada for her kind cooperation in preparing the T-CNF. This work is based on experiments performed at the Swiss spallation neutron source SINQ, Paul Scherrer Institute, Villigen, Switzerland. Beamtime was allocated on the FOCUS instrument, proposal 20212665. The authors gratefully acknowledge the Science and Technology Facilities Council (STFC) for access to neutron beamtime at the TOSCA instrument at ISIS, proposal RB2220550. The SANS experiment at the Materials and Life Science Experimental Facility of J-PARC was performed under a user program, proposal 2023B0102, at the BL-15TAIKAN instrument. The authors acknowledge DESY (Hamburg, Germany),a member of the Helmholtz Association HGF, for the provision of experimental facilities. Part of this research was carried out at PETRA III, P62beamline, proposal I-20230270 EC.
2025-01-292025-01-292025-09-23Bibliographically approved