Why Is Aerogel A Good Thermal Insulator

The solid component in silica aerogel consists of tiny, three-dimensional, intertwined clusters. They comprise only 3% of the volume and are very poor conductors. Air in microscopic pores make up the remaining 97% of aerogel's volume. This air has very little room to move, inhibiting both convection and gas-phase conduction. These characteristics make aerogel the world's lowest density solid and most effective thermal insulator.