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Ultra-Porous Nanocellulose Foams: A Facile and Scalable Fabrication Approach

Authors :
Carlo Antonini
Tingting Wu
Tanja Zimmermann
Abderrahmane Kherbeche
Marie-Jean Thoraval
Gustav Nyström
Thomas Geiger
Source :
Nanomaterials, Vol 9, Iss 8, p 1142 (2019)
Publication Year :
2019
Publisher :
MDPI AG, 2019.

Abstract

Cellulose nanofibril foams are cellulose-based porous materials with outstanding mechanical properties, resulting from the high strength-to-weight ratio of nanofibrils. Here we report the development of an optimized fabrication process for highly porous cellulose foams, based on a well-controlled freeze-thawing-drying (FTD) process at ambient pressure. This process enables the fabrication of foams with ultra-high porosity, up to 99.4%, density of 10 mg/cm3, and liquid (such as oil) absorption capacity of 100 L/kg. The proposed approach is based on the ice-templating of nanocellulose suspension in water, followed by thawing in ethanol and drying at environmental pressures. As such, the proposed fabrication route overcomes one of the major bottle-necks of the classical freeze-drying approach, by eliminating the energy-demanding vacuum drying step required to avoid wet foam collapse upon drying. As a result, the process is simple, environmentally friendly, and easily scalable. Details of the foam development fabrication process and functionalization are thoroughly discussed, highlighting the main parameters affecting the process, e.g., the concentration of nanocellulose and additives used to control the ice nucleation. The foams are also characterized by mechanical tests and oil absorption measurements, which are used to assess the foam absorption capability as well as the foam porosity. Compound water-in-oil drop impact experiments are used to demonstrate the potential of immiscible liquid separation using cellulose foams.

Details

Language :
English
ISSN :
20794991
Volume :
9
Issue :
8
Database :
Directory of Open Access Journals
Journal :
Nanomaterials
Publication Type :
Academic Journal
Accession number :
edsdoj.11b8fc4cba8e4d9b8cb7a180a1fe618c
Document Type :
article
Full Text :
https://doi.org/10.3390/nano9081142