Highly Stretchable, Crack-Insensitive and Compressible Ceramic Aerogel.

Area of Science:

• Materials Science
• Nanotechnology
• Ceramics

Background:

• Ceramic aerogels offer high-temperature thermal insulation and catalysis support but suffer from brittleness.
• Recent advances introduced reversible compressibility, yet tensile fracture remains an issue.

Purpose of the Study:

• To engineer ceramic aerogels with reversible stretchability and crack insensitivity.
• To explore the potential of curly SiC-SiO bicrystal nanowires for advanced aerogel design.

Main Methods:

• Fabrication of ceramic aerogels using curly SiC-SiO bicrystal nanowires as building blocks.
• Mechanical testing including large-strain reversible stretch, tensile fatigue, and compressibility tests.
• Evaluation of thermal properties and stability at extreme temperatures (-196 °C to 1200 °C).

Main Results:

• Achieved reversible stretch up to 20% and crack insensitivity in prenotched samples (10% reversible stretch).
• Demonstrated reversible compressibility up to 80% strain.
• Exhibited ultralow thermal conductivity (28.4 mW m^-1 K^-1) and excellent thermal stability.

Conclusions:

• The unique microstructure of curly nanowires enables exceptional tensile properties by mitigating stress concentration and crack propagation.
• This work expands the application scope of ceramic aerogels for dynamic stress conditions at extreme temperatures.
• Provides a design strategy for developing highly stretchable and crack-resistant porous ceramic materials.