Oxide aerogel is a novel nano-porous material with ultra-low thermal conductivity. In particular, it can be used in spaceflight applications and other thermal management fields. Currently, with high infrared transmittance, most of the common pure oxide aerogels, such as silica and alumina, have no advantages in high-temperature insulation because of their intrinsic property. However, electromagnetic radiation in the near-infrared region is the main mode of heat conduction at high temperatures, accordingly, a large amount of electromagnetic radiation will pass through aerogel and lead to the rapid increase of thermal conductivity. Therefore, to meet the requirement of thermal insulation at higher temperature, it is necessary to reduce the radiative heat transfer. Based on the research status, this paper reviewed the main progress of improving high temperature insulation of oxide aerogel by adding opacifier, fiber and adjusting the structure and morphology. Moreover, the future research direction has prospected.

Contents

1 Introduction

2 Application of opacifiers in infrared modification of aerogels

2.1 TiO₂ opacifier

2.2 SiC opacifier

2.3 Carbon materials opacifier

2.4 Other opacifier

3 Application of fiber in infrared modification of aerogels

3.1 Glass fiber

3.2 ZrO₂ fiber

3.3 Mullite fiber

3.4 Modified fiber

4 Application of structure/morphology change in infrared modification of aerogels

4.1 Multiple-layer aerogel insulation materials

4.2 Lamellar aerogels

4.3 Nanofiber aerogels

5 Conclusion and outlook