Opacified graphene-doped silica aerogels with controllable thermal conductivity

Abstract

In this work, we developed a new type of thermal insulation materials by combining the silica aerogel (SiO2) and graphene (G) followed by aging and supercritical drying. The effects of different G/SiO2 mass ratios on the microstructures and properties of opacified G/SiO2-x composite aerogels were investigated. The results showed that the graphene was well-distributed in the SiO2 matrix. Meanwhile, the opacified composite aerogels showed high-specific surface area (~ 1000 m2/g). Due to the unique bandgap feature and conjugated large π bond of graphene, the thermal insulation property of G/SiO2-x composite aerogels was enhanced in contrast with the pure SiO2 aerogel. Moreover, a possible mechanism of heat transfer was discussed to interpret the result.