TiO₂ Nanorod Array-Enhanced Si₃N₄ Nanoribbon Aerogels with Superior High-Temperature Insulation

Area of Science:

• Materials Science
• Nanotechnology
• Ceramic Engineering

Background:

• Ceramic aerogels require infrared opacifiers to reduce radiative heat transfer at high temperatures.
• Achieving a strong interface between opacifiers and aerogel networks is crucial for stability.

Purpose of the Study:

• To enhance the thermal insulation efficiency of ceramic aerogels at high temperatures.
• To improve the structural and functional stability of ceramic aerogels.

Main Methods:

• In situ growth of titanium dioxide nanorod (TiONR) arrays onto silicon nitride nanoribbon (SiNNR) aerogels using a hydrothermal reaction.
• Tuning TiONR array density by adjusting reaction time for complete encapsulation.

Main Results:

• TiONR/SiNNR aerogels showed a significantly lower increase in thermal conductivity (82%) compared to SiNNR aerogels (231%) from room temperature to 800 °C.
• The TiONR array effectively suppressed radiative heat transfer.
• A robust TiONR-SiNNR interface provided flexibility and oxidation protection.

Conclusions:

• Grafting opacifier arrays onto aerogel building blocks is an effective strategy for enhancing high-temperature insulation.
• This method simultaneously improves oxidation resistance and maintains structural integrity of ceramic aerogels.