Thermal Conductivity of Porous and Dense Networks of Cellulose Nanocrystals

↓ Direkt till sidans innehåll
↓ Direkt till sidans sekundära innehåll (sidomenyn)

Search: id:"swepub:oai:DiVA.org:umu-198264" > Thermal Conductivit...

1 of 1
Previous record
Next record
To hitlist

Details
MARC

Antlauf, MathisUmeå universitet,Institutionen för fysik (author)

Thermal Conductivity of Porous and Dense Networks of Cellulose Nanocrystals

Article/chapterEnglish2022

Publisher, publication year, extent ...

2022-06-17
American Chemical Society (ACS),2022
electronicrdacarrier

Numbers

LIBRIS-ID:oai:DiVA.org:umu-198264
https://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-198264URI
https://doi.org/10.1021/acs.macromol.2c00153DOI

Supplementary language notes

Language:English
Summary in:English

Part of subdatabase

SwePubSwePub

Classification

Subject category:ref swepub-contenttype
Subject category:art swepub-publicationtype

Notes

Cellulose is a crystalline polymer with intriguing, amorphous-like, temperature dependence of thermal conductivity κ. To determine its origin, we have studied κ of cellulose nanocrystals (CNCs) derived from cotton by sulfuric acid hydrolysis, in both porous and nonporous states by pressure densification; κ increases weakly with increasing temperature and density, like in a fully amorphous material, and it is remarkably similar to that of cellulose fibers (CFs) and cellulose nanofibers (CNFs). For a powder derived from a natural material, like cellulose, amorphous-like κ may originate from poor thermal contact between particles or a high amorphous content, but the latter is not the case for CNCs. Moreover, the amorphous-like behavior is unaffected by densification and, therefore, improved thermal contacts. Instead, we attribute the behavior to CNCs' nanometer-sized fibrils, which limit the phonon mean free path to a few nanometers in a network of randomly oriented CNCs. This explains why κ is essentially the same in networks of CNCs, CFs, and CNFs, which are materials with the same structural unit-elementary fibrils of 3-5 nm in diameter. We obtain κ = (0.60 ± 0.01) W m-1 K-1 for a nonporous network of randomly oriented CNCs at 295 K and atmospheric pressure, and κ increases by only 14% GPa-1, which is unusually weak for a polymer. By using a model for such a network, we find κ = 1.9 W m-1 K-1 along a CNC and argue that this is a good estimate also along a CNF and a CF at room temperature.

Subject headings and genre

Added entries (persons, corporate bodies, meetings, titles ...)

Andersson, OveUmeå universitet,Institutionen för fysik(Swepub:umu)ovan0001 (author)
Umeå universitetInstitutionen för fysik (creator_code:org_t)

Related titles

In:Macromolecules: American Chemical Society (ACS)55:13, s. 5326-53310024-92971520-5835

Internet link

Find in a library

Macromolecules (Search for host publication in LIBRIS)

To the university's database

1 of 1
Previous record
Next record
To hitlist

Find more in SwePub

By the author/editor: Antlauf, Mathis; Andersson, Ove

About the subject

ENGINEERING AND TECHNOLOGY: ENGINEERING AND ...; and Chemical Enginee ...; and Polymer Technolo ...

Articles in the publication: Macromolecules

By the university: Umeå University

Search outside SwePub

Extend your search to:: Google; Google Book Search; Google Scholar

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

LIBRIS.kb.se