Strong yet superelastic ceramic aerogel enabled by synergistic soft-hard inter-nanowire nodes

Area of Science:

• Materials Science
• Nanotechnology
• Ceramic Engineering

Background:

• Elastic ceramic aerogels are crucial for aerospace, energy storage, and thermal protection due to their lightweight, thermal stability, and mechanical robustness.
• A key limitation in their application is insufficient mechanical strength, as high strength and elasticity are often mutually constrained in ceramic nanowire aerogels.

Purpose of the Study:

• To design and develop silicon carbide nanowire aerogels with enhanced strength and elasticity.
• To resolve the conflict between high strength and high elasticity in ceramic aerogels.

Main Methods:

• Fabrication of silicon carbide nanowire aerogels reinforced with dual-phase nodes (pyrolytic carbon and amorphous silica).
• Experimental characterization of mechanical properties.
• Large-scale atomic/molecular massively parallel simulator (LAMMPS) and finite element simulations to understand mechanical behavior.

Main Results:

• The dual-phase nodes, comprising amorphous silica (SiO2) and pyrolytic carbon (PyC), exhibit a synergistic effect.
• Amorphous SiO2 enhances load distribution, while PyC prevents premature fracture, leading to improved mechanical performance.
• The resulting aerogels achieved a compressive strength of 10.9 MPa at 80% strain and approximately 90% resilience.

Conclusions:

• The dual-phase node strategy effectively enhances both strength and elasticity in ceramic aerogels.
• This approach offers a viable method for tailoring mechanical responses of aerogels for extreme environments.
• The developed aerogels show promise for applications requiring high strength, elasticity, and reliability under challenging conditions (high temperature, low oxygen, vacuum).