Combining and concentrating nanocelluloses for cryogels with remarkable strength and wet resilience.
Carbohydr Polym
; 330: 121740, 2024 Apr 15.
Article
em En
| MEDLINE
| ID: mdl-38368119
ABSTRACT
Cellulose cryogels are promising eco-friendly materials that exhibit low density, high porosity, and renewability. However, the applications of these materials are limited by their lower mechanical and water resistance compared to petrochemical-based lightweight materials. In this work, nanocelluloses were functionalized with cationic and anionic groups, and these nanomaterials were combined to obtain strong and water-resilient cryogels. To prepare the cryogels, anionic and cationic micro- and nanofibrils (CNFs) were produced at three different sizes and combined in various weight ratios, forming electrostatic complexes. The complex phase was concentrated by centrifugation and freeze-dried. Porous and open cellular structures were assembled in all compositions tested (porosity >90 %). Compressive testing revealed that the most resistant cryogels (1.7 MPa) were obtained with equivalent amounts of negatively and positively charged CNFs with lengths between 100 and 1200 nm. The strength at this condition was achieved as CNF electrostatic complexes assembled in thick cells, as observed by synchrotron X-ray tomography. In addition to mechanical strength, electrostatic complexation provided remarkable structural stability in water for the CNF cryogels, without compromising their biodegradability. This route by electrostatic complexation is a practical strategy to combine and concentrate nanocelluloses to tailor biodegradable lightweight materials with high strength and wet stability.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Carbohydr Polym
Ano de publicação:
2024
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Reino Unido