Direct Volumetric Measurement of Gas Oversolubility in Nanoliquids: Beyond Henry’s Law

Abstract

The properties of condensed matter are strongly affected by confinement and size effects at the nanoscale. Herein, we measured by microvolumetry the increased solubility of H(2) in a series of solvents (CHCl(3), CCl(4), n-hexane, ethanol, and water) when confined in the cavities of mesoporous solids (gamma-alumina, silica, and MCM-41). Gas/liquid solubilities are enhanced by up to 15 times over the corresponding bulk values for nanoliquid sizes smaller than 15 nm as long as gas/liquid interfaces are mesoconfined in a porous network. Although Henry's law constant apparently no longer applies under these confinement, the concentration of dissolved H(2) still increases linearly with increasing pressure in the range 1-5 bar. We discuss the role and main implications of surface excess concentrations at mesoconfined gas/liquid interfaces in enhancing gas solubility.