Bamboo Leaf Aerogel Opacified with Activated Carbon

Opacification of silica aerogel to reduce its thermal conductivity is normally done by using carbon. The motivation of this work is to use bamboo leaf as a single source to synthesize water glass and activated carbon. These precursors were then used to synthesize carbon-opacified silica aerogel (COSA). Because bamboo leaf is an agriculture waste, it provides a low-cost source to synthesize COSA. The properties of COSA were compared with other aerogels, including aerogel opacified with carbon black and synthesized from alkoxide. The results indicate that COSA have a bulk density of 0.069±0.0014 g.cm^–3, a porosity of 97.9%, a BET specific surface area of 330.5±3.7 m².g^–1, a total pore volume of 1.38±0.07cm³.g^–1 and a thermal conductivity of 0.0311±0.009 W.m^–1.K^–1. The TGA results show that COSA is thermally stable up to 495°C and is therefore suitable for use in thermal insulation at high temperature.