Superinsulating nanocellulose aerogels: Effect of density and nanofiber alignment.
Carbohydr Polym
; 292: 119675, 2022 Sep 15.
Article
em En
| MEDLINE
| ID: mdl-35725170
ABSTRACT
Cellulose aerogels are potential alternatives to silica aerogels with advantages in cost, sustainability and mechanical properties. However, the density dependence of thermal conductivity (λ) for cellulose aerogels remains controversial. Cellulose aerogels were produced by gas-phase pH induced gelation of TEMPO-oxidized cellulose nanofibers (CNF) and supercritical drying. Their properties are evaluated by varying the CNF concentration (5-33 mg·cm-3) and by uniaxial compression (9-115 mg·cm-3). The aerogels are transparent with specific surface areas of ~400 m2·g-1, mesopore volumes of ~2 cm3·g-1 and a power-law dependence of the E-modulus (α ~ 1.53, and the highest reported E of ~1 MPa). The dataset confirms that λ displays a traditional U-shaped density dependence with a minimum of 18 mW·m-1·K-1 at 0.065 g·cm-3. For a given density, λ is ~5 mW·m-1·K-1 lower for compressed aerogels due to the alignment of nanofibers, confirmed by small angle X-ray scattering (SAXS).
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Nanofibras
Idioma:
En
Revista:
Carbohydr Polym
Ano de publicação:
2022
Tipo de documento:
Article