Open AccessNanostructurally Controllable Strong Wood Aerogel toward Efficient Thermal Insulation
Author(s) -
Jonas Garemark,
Jesus E. PereaBuceta,
Daniel Rico del Cerro,
Stephen A. Hall,
Barbara Berke,
Ilkka Kilpeläinen,
Lars A. Berglund,
Yuanyuan Li
Publication year - 2022
Publication title -
acs applied materials and interfaces
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.535
H-Index - 228
eISSN - 1944-8252
pISSN - 1944-8244
DOI - 10.1021/acsami.2c04584
Subject(s) - aerogel , materials science , thermal insulation , composite material , cellulose , nanostructure , isotropy , thermal conductivity , fabrication , dissolution , chemical engineering , nanotechnology , medicine , physics , alternative medicine , layer (electronics) , quantum mechanics , pathology , engineering
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 m 2 /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.