Experimental Investigation of Pressure on the Thermal Conductivity of Granular Carbon Aerogels

Abstract

The thermal conductivity of granular carbon aerogels was measured using the transient hot-strip method under different pressure conditions through the design and construction of a high-pressure chamber and a vacuum chamber to provide a pressure environment ranging from 10−2 Pa to 30 MPa. The microstructure and specific surface area of the material were characterized through the cryogenic nitrogen adsorption method and scanning electron microscope images. Analysis of the experimental results showed that the thermal conductivity of the granular sample reached a constant when the pressure was less than 100 Pa, and the thermal conductivity of the sample showed a similar change trend (i.e., increased with pressure) under two different gas atmospheres. When the pressure was higher than 1000 Pa, the thermal conductivity increased significantly and the high rate of change continued until the pressure increased to 5 MPa, at which point the increase in thermal conductivity slowed.