Bioinspired Lignocellulose Foam: Exceptional Toughness and Thermal Insulation.

Area of Science:

• Materials Science
• Biomaterials Engineering
• Sustainable Chemistry

Background:

• Petrochemical foams pose environmental and sustainability challenges.
• Limited mechanical stability hinders the practical application of current biofoams.
• Natural structures offer inspiration for advanced material design.

Purpose of the Study:

• To develop a biodegradable lignocellulosic biofoam with enhanced mechanical stability and thermal insulation.
• To utilize a synergistic strategy combining structural bionics and supramolecular cross-linking.
• To create a sustainable alternative to petrochemical foams.

Main Methods:

• Fabrication of a "pillar-spacer" microlattice biofoam using multiscale cellulose fibers (CFs) and sodium lignin sulfonate (SLS).
• Inspiration from cuttlebone's natural structure for biofoam design.
• Integration of a functional SiO2 nanocoating for flame retardancy.

Main Results:

• The CFs/SLS biofoam achieved a low density (62 mg cm-3) and a compression modulus of 6.56 MPa, nearly four times higher than CF biofoam.
• Exceptional thermal insulation with a thermal conductivity of 0.046 W m-1 K-1.
• SiO2@CFs/SLS foam demonstrated satisfactory flame retardation and smoke inhibition without compromising performance.

Conclusions:

• The developed biofoam offers a sustainable, eco-friendly, and mechanically robust alternative to petrochemical foams.
• The synergistic approach of structural bionics and supramolecular cross-linking is effective for enhancing biofoam properties.
• This research highlights the potential of lignocellulosic materials for advanced applications.