The thermal conductivity (λ) of glass foams is thought to depend on pore size. We report on the impact of pore size, determined using X-ray microtomography, and percentage porosity on the λ of glass foams. Glass foams were prepared by heating powder mixtures of obsolete cathode ray tube (CRT) panel glass, Mn3O4 and carbon as foaming agents, and K3PO4 as additive, to a suitable temperature above Tg, and subsequent cooling. Here, we report for the first time a correlation between λ and pore size in the range 0.10–0.16 mm showing a decrease from 57–49 mW m-1 K-1 with increasing the pore for glass foams with porosities of 87–90 %. This indicates that the pore structure should be optimized in order to improve the insulating performance of glass foams.
- Amorphous materials
- Porous materials
- Thermal propertiesX-ray techniques