Nanostructurally Controllable Strong Wood Aerogel toward Efficient Thermal Insulation
Journal article, 2022

Eco-friendly materials with superior thermal insulation and mechanical properties are desirable for improved energy- and space-efficiency in buildings. Cellulose aerogels with structural anisotropy could fulfill these requirements, but complex processing and high energy demand are challenges for scaling up. Here we propose a scalable, nonadditive, top-down fabrication of strong anisotropic aerogels directly from wood with excellent, near isotropic thermal insulation functions. The aerogel was obtained through cell wall dissolution and controlled precipitation in lumen, using an ionic liquid (IL) mixture comprising DMSO and a guanidinium phosphorus-based IL [MTBD][MMP]. The wood aerogel shows a unique structure with lumen filled with nanofibrils network. In situ formation of a cellulosic nanofibril network in the lumen results in specific surface areas up to 280 m2/g and high yield strengths >1.2 MPa. The highly mesoporous structure (average pore diameter 20 nm) of freeze-dried wood aerogels leads to low thermal conductivities in both the radial (0.037 W/mK) and axial (0.057 W/mK) directions, showing great potential as scalable thermal insulators. This synthesis route is energy efficient with high nanostructural controllability. The unique nanostructure and rare combination of strength and thermal properties set the material apart from comparable bottom-up aerogels. This nonadditive synthesis approach is believed to contribute significantly toward large-scale design and structure control of biobased aerogels.

sustainable materials

wood

ionic liquid

thermal insulation

aerogel

Author

Jonas Garemark

Royal Institute of Technology (KTH)

Jesus E. Perea-Buceta

University of Helsinki

Daniel Rico del Cerro

University of Helsinki

S. Hall

Lund University

Barbara Berke

Chalmers, Physics, Materials Physics

I. Kilpelainen

University of Helsinki

L. Berglund

Royal Institute of Technology (KTH)

Yuanyuan Li

Royal Institute of Technology (KTH)

ACS Applied Materials & Interfaces

1944-8244 (ISSN) 1944-8252 (eISSN)

Vol. 14 21 24697-24707

Subject Categories

Materials Chemistry

Building Technologies

Composite Science and Engineering

DOI

10.1021/acsami.2c04584

PubMed

35511115

More information

Latest update

3/7/2024 9