Comment on E. PrudʹHomme et al., “Structural characterization of geomaterial foams — Thermal behavior”, J. Non-Cryst. Solids, 2011

We provide a discussion of a recent paper in Journal of Non-Crystalline Solids (E. PrudʹHomme et al., “Structural characterization of geomaterial foams — Thermal behavior”, J. Non-Cryst. Solids, 2011, in press), and in particular propose a revised interpretation of the NMR spectra in terms of silicate site connectivity. This new interpretation is consistent with the infrared spectroscopic and thermogravimetric data presented in the same study, and also with known trends in geopolymer gel development as a function of the nature of the alkali cations present.