Specific surface area and neutron scattering analysis of water’s glass transition and micropore collapse in amorphous solid water

Physico-chemical instability is commonly associated with the amorphous state, and the understanding of instability mechanisms (e.g. the glass transition) involved is essential in designing pharmaceutical products. The glass transition of bulk water might occur at 210 K [Oguni et al., J. Phys. Chem. B 115 (2011) 14023] but it was recently proposed the glass transition of water could happen around 121 K [C. R. Hill et al., Phys. Rev. Lett. 116 (2016) 215501]. Note that molecular self-inclusions in a glassy water show relaxation features that are characteristically different from those observed in thermodynamically stable, crystalline solids with inclusions. Here we point out some doubtful results and calculations in Hill et al.’s work [C. R. Hill et al., Phys. Rev. Lett. 116 (2016) 215501] which was based on the small-angle neutron scattering (SANS) measurements. We also made some remarks about the possible mistakes in their previous works [C. Mitterdorfer, Phys. Chem. Chem. Phys. 16 (2014) 16013] considering the calculation of the specific surface area. The latter is crucial to the doubtful fixing of the glass transition temperature in Hill et al.’s work [C. R. Hill et al., Phys. Rev. Lett. 116 (2016) 215501].