Study of water escape and invasion in nanoporous alumina using GASMAS and gravimetric methods

• Compare gravimetric and Gas in Scattering Media Absorption Spectroscopy (GASMAS) methods in assessing the escape and invasion times of water in nanoporous alumina with average pore sizes: 50, 80 and 150 nm. • GASMAS method has the capability of distinguishing between water vapor and liquid content in the nanoporous alumina and assessing them simultaneously. • The escape and invasion times of water in nanoporous alumina are inversely proportional to the average pore size. This study investigates water escape and invasion dynamics in commercial alumina discs, which have sharp size distributions and average pore sizes of 50, 80, and 150 nm, using two different methods, namely, gravimetric and Gas in Scattering Media Absorption Spectroscopy (GASMAS). Before performing measurements in ambient air, the samples were initially placed in a water-saturated environment for the escape study, while for the invasion study, they were initially put in a vacuum environment. Both methods were found to agree and revealed that the time constants for escape and invasion processes were inversely proportional to the average pore sizes. However, the GASMAS method has the capability of distinguishing between water vapor and liquid content in the samples and assessing them simultaneously.