Influence of the mesoconfining solid on gas oversolubility in nanoliquids

In this study, we have measured the solubility of hydrogen in n-hexane and ethanol confined in a series of mesoporous materials displaying different texture and pore morphology. In all cases, hydrogen solubility increases dramatically over bulk values when the liquid size is reduced down to 5–15 nm. In the case of coarse-grained and mesostructured materials, this ‘oversolubility’ effect is apparently ascribed to a role of surface excess concentrations at mesoconfined gas/liquid interfaces. However, in the case of n-hexane confined in silica aerogel, much higher values are observed. We argue about a possible role of liquid reconstruction, providing higher molecular order in the liquid, to explain this result.