Microstructure and Thermal Insulation Property of Silica Composite Aerogel

Abstract

Tetraethyl orthosilicate was selected as a matrix of heat insulating materials among three silanes, and an anti-infrared radiation fiber was chosen as a reinforcement for silica aerogel insulation composite. The silica aerogel was combined well and evenly distributed in the anti-infrared radiation fiber. The heat insulation effect was improved with the increase in thickness of the aerogel insulation material, as determined by the self-made aerospace insulation material insulation performance test equipment. The 15 mm and 30 mm thick thermal insulation material heated at 250 °C for 3 h, the temperatures at the cold surface were about 80 °C and 60 °C, respectively, and the temperatures at 150 mm above the cold surface were less than 60 °C and 50 °C, respectively. The silica aerogel composites with various thicknesses showed good thermal insulation stability. The silica insulation composite with a thickness of 15 mm exhibited good heat insulation performance, meets the thermal insulation requirements of general equipment compartments under low-temperature and long-term environmental conditions. The thermal conductivity of prepared silica aerogel composite was 0.0191 W·m−1·k−1 at room temperature and 0.0489 W·m−1·k−1 at 500 °C.

Application of Silica Aerogel in Composites Protecting Against Thermal Radiation

“…This may be explained by the compromised structure of aerogel, which affected its properties. It should be noted that Shang et al [38] observed changes in the thermal conductivity of silica aerogel composites under the infl uence in an aluminum foil to heat fl uxes of 35 and 60 kW/m 2 , observed that composites became slightly yellowish. The higher heat fl ux of 60 kW/m 2 resulted in a partial combustion of composites, leaving behind black charred remains and white silica residues.…”

Preparation and Characterization of High Amylose Corn Starch–Microcrystalline Cellulose Aerogel with High Absorption

“…However, they generally have the disadvantage of a poor absorbency and reusability. On the other hand, inorganic aerogels, such as SiO 2 aerogel [4], graphene oxide aerogel [5] and others, exhibit a high absorption capacity, high porosity, and large specific surface area. However, the degradation of most of inorganic aerogels remains a major environmental challenge and may cause secondary pollution, which greatly limits their application.…”

Hybrid RF-Si Xerogels: A Cost-Effective Proposal for Insulator Materials

“…Silica aerogels have the most extended use as superinsulators since their porous network is formed mainly by narrow pores (i.e., micro and mesopores), and they have a high porosity [ 1 , 3 , 14 ]. The small pore sizes of these aerogels allow nullification of the convection and gas conductivity, so only radiation and solid conductivity contribute to the heat transfer process [ 8 , 15 ]. These materials reach thermal conductivities around 10–20 mW/mK and have a wide variety of applications [ 9 , 13 ].…”