Ion-Specific and Thermal Effects in the Stabilization of the Gas Nanobubble Phase in Bulk Aqueous Electrolyte Solutions

Abstract

Ion-stabilized nanobubbles in bulk aqueous solutions of various electrolytes were investigated. To understand the ion-specific mechanism of nanobubble stabilization, an approach based on the Poisson--Boltzmann equation at the nanobubble interface and in the near-surface layer was developed. It has been shown that the stabilization of nanobubbles is realized by the adsorption of chaotropic anions at the interface, whereas the influence of cosmotropic cations is weak. With increasing temperature, it should be accounted for by blurring the interface due to thermal fluctuations. As a result, the adsorbed state of ions becomes unstable: the nanobubble loses its stability and vanishes. This prediction was proven in our experiments. It turned out that in the case of liquid samples being kept in hermetically sealed ampules, where the phase equilibrium at the liquid-gas interface is fulfilled for any temperature, the volume number density of nanobubbles decreases with increasing temperature and this decrease is irreversible.

Plasma physics of liquids—A focused review

“…196 Bulk phase nanobubbles can be as small as 10 nm in diameter, 179 but typical sizes range between 100 and 300 nm. 179,[197][198][199][200] Various solution preparation methods generally lead to number densities between 10 12 and 10 15 m À3 , [197][198][199][200] although values up to 1.9 Â 10 19 m À3 have been obtained. 186 Detection techniques include light scattering, 184 cryoelectron microscopy, 201 and a resonant mass measurement method that can distinguish the bubbles from liquid emulsion or solid nanoparticles.…”

Collective modes of two-dimensional classical Coulomb fluids

“…First, 2D systems play an important practical role in a broad range of phenomena occurring at fluid and solid surfaces and various interfaces. Examples are atomic monolayers and thin films on substrates, 2D electron fluid on the surface of liquid helium, 3 metallic and magnetic layer compounds, colloidally stabilized emulsions and bubbles, 4,5 colloidal particles at flat interfaces, 6,7 complex (dusty) plasma systems in ground-based laboratory conditions. [8][9][10] Second, physics in two-dimensions (2D) can be fundamentally different from that in threedimensions (3D).…”

“…Collective modes of the 2D Coulomb fluid with Γ = 100. Circles correspond to frequencies ω l,t and triangles to ω l,t ± γ l,t , obtained by applying a fitting function(5) to the MD data. Red (blue) color corresponds to the longitudinal (transverse) dispersion.…”

Electrically controlled cloud of bulk nanobubbles in water solutions

“…Yurchenko et al . [19] proposed that charges on the gas-water interface are responsible for exceptional stability of the NBs. In a series of papers by Kikuchi et al .…”