Fig. 2: Aerogel–silicone composite and its thermal conductivity.

a A cross-sectional optical microscope image of the aerogel–silicone composite. b Thermal conductivity measurement system. c Thermal conductivity of the composite for two different aerogel particle sizes of 2–40 and 100–700 μm plotted as a function of the aerogel volume fraction. d A cross-sectional scanning electron microscope image of the aerogel–silicone interface.