Why are oxide glasses useful as thermal insulators?

Oxide glasses are effective thermal insulators primarily due to their unique atomic structure, which is characterized by a random, noncrystalline arrangement of atoms. Unlike crystalline solids, which possess a highly ordered lattice that facilitates the efficient transport of heat via phonons—units of vibrational energy—the disordered structure of glass disrupts this process.1234

In oxide glasses, thermal conductivity resulting from atomic vibrations does not increase significantly with temperature because the lack of a periodic lattice limits the propagation of these vibrational waves. Furthermore, the specific composition of these glasses—such as the connectivity of the network and the presence of modifying ions—influences their physical properties, including their ability to resist heat transfer. Because glass acts as a nearly perfect elastic solid at ordinary temperatures, it maintains these insulating characteristics while remaining highly resistant to many corrosive media.342