Enhanced Oxygen Solubility in Metastable Water under Tension

Abstract

Despite its relevance in numerous natural and industrial processes, the solubility of molecular oxygen has never been directly measured in capillary-condensed liquid water. In this article, we measure oxygen solubility in liquid water trapped within nanoporous samples, in metastable equilibrium with a subsaturated vapor. We show that solubility increases two fold at moderate subsaturations (relative humidity ∼0.55). This evolution with relative humidity is in good agreement with a simple thermodynamic prediction using properties of bulk water, previously verified experimentally at positive pressure. Our measurement thus verifies the validity of this macroscopic thermodynamic theory to strong confinement and large negative pressures, where significant nonidealities are expected. This effect has strong implications for important oxygen-dependent chemistries in natural and technological contexts.

Regeneration of capillary water in unsaturated zones

“…These experiments show that capillarity has an effect on in-pore gas liquid interaction and are in line with previous measurements that demonstrated the supersolubility of gas in capillary water (Lassin et al, 2016;Lidon et al, 2018). Those were conducted in nanoporous natural material; here we extend the gas supersolubility effect to larger pores in heterogeneous porous media.…”

“…Recent experimental studies agree for CO 2 (Lassin et al, 2016) and O 2 (Lidon et al, 2018) gases and for salts (Hulin and Mercury, 2019).…”

No gas source, no problem: Proximity to pre‐existing embolism and segmentation affect embolism spreading in angiosperm xylem by gas diffusion

“…However, the continuous nature of gas diffusion and the high amounts of gas surrounding conduits (Spicer & Holbrook, 2005; Teskey, Saveyn, Steppe, & McGuire, 2008) do not mean that gas concentration in xylem sap is always under equilibrium with gas in embolized conduits, as has frequently been assumed (Hammel, 1967; Schenk, Espino, Visser, & Esser, 2016; Wheeler et al, 2013; Yang & Tyree, 1992). Gas solubility of xylem sap is affected by pressure and temperature (Lidon et al, 2018; Mercury, Azaroual, Zeyen, & Tardy, 2003; Schenk et al, 2016). Owing to a nearly constant atmospheric pressure in a cut‐open vessel, but a considerably variable liquid water pressure in sap‐filled conduits, the driving force for gas diffusion is the unbalanced anisobaric situation between embolized conduits and functional conduits.…”

Nanobubble-controlled nanofluidic transport

“…Because of being under tension, the gas solubility of the interfacial electrolyte increases (54) to support nanobubble growth (Fig. 4C, red dashed curve).…”