Study of the effects of confined water vapor in mesoporous silica on its mass transport analysis for thermal energy storage applications

This study examines the mass transport of mesoporous silica under controlled humidity conditions, with a focus on the effects of confined water vapor. We quantitatively monitored the evaporation and diffusion dynamics of water vapor within MCM-41 and SBA-15 silica structures using Gas in Scattering Media Absorption Spectroscopy (GASMAS). Complementary characterization techniques, such as thermogravimetric analysis (TGA), and BET surface area measurements, demonstrated that pore morphology and water confinement significantly impact mass transport and thermal tranfer dynamics. The GASMAS results demonstrate that the time constants for water vapor desorption are dependent on the material, with MCM-41 exhibiting a value of 45 minutes and SBA-15 showing a value of 67 minutes. These differences can be attributed to variations in pore size and structural architecture. These findings demonstrate the ability to modify mass transfer in mesoporous silica through modifications in pore shape and moisture levels, providing significant insights for enhancing thermal transfer in energy storage, construction, and aerospace industries.