Nanostructurally Controllable Strong Wood Aerogel toward Efficient Thermal Insulation

Area of Science:

• Materials Science
• Nanotechnology
• Sustainable Building Materials

Background:

• Cellulose aerogels offer excellent thermal insulation and mechanical properties for energy-efficient buildings.
• Current challenges include complex processing and high energy demands for scalable production.
• Anisotropic cellulose aerogels from wood are desirable but difficult to fabricate efficiently.

Purpose of the Study:

• To propose a scalable, nonadditive, top-down fabrication method for strong, anisotropic wood aerogels.
• To achieve excellent, near-isotropic thermal insulation properties in the fabricated aerogels.
• To demonstrate a sustainable and energy-efficient synthesis route for biobased aerogels.

Main Methods:

• Utilized an ionic liquid (IL) mixture (DMSO and [MTBD][MMP]) for wood cell wall dissolution and controlled precipitation.
• Fabricated aerogels directly from wood using a top-down approach.
• Employed freeze-drying to create a highly mesoporous structure.

Main Results:

• Obtained wood aerogels with a unique structure featuring a nanofibril network within the wood lumen.
• Achieved high specific surface areas (up to 280 m²/g) and yield strengths (>1.2 MPa).
• Demonstrated low thermal conductivities (0.037 W/mK radial, 0.057 W/mK axial) due to a mesoporous structure (∼20 nm).

Conclusions:

• The proposed nonadditive synthesis is scalable, energy-efficient, and offers high nanostructural control.
• Wood aerogels exhibit a unique nanostructure with a rare combination of strength and thermal insulation properties.
• This method shows significant potential for large-scale production of advanced biobased aerogels for thermal insulation.