The quasi-static growth of CO₂ bubbles

Abstract

We study experimentally the growth of an isolated gas bubble in a slightly supersaturated water-CO 2 solution at 6 atm pressure. In contrast to what was found in previous experiments at higher supersaturation, the time evolution of the bubble radius differs noticeably from existing theoretical solutions. We trace the differences back to several combined effects of the concentration boundary layer around the bubble, which we disentangle in this work. In the early phase, the interaction with the surface on which the bubble grows slows down the process. In contrast, in the final phase, before bubble detachment, the growth rate is enhanced by the onset of density-driven convection. We also show that the bubble growth is affected by prior growth and detachment events, though they are up to 15 min apart.

Dissolution of a spherical cap bubble adhered to a flat surface in air-saturated water

“…The interaction of the boundary layer with the plate may be modelled following the approach proposed by Enríquez et al (2014). The effective spherical cap area, S eff ,i (t), across which mass transfer of the ith gas species is allowed, is dependent on the boundary layer thickness λ i (t), and it is estimated as shown in figure 5.…”

Gas depletion through single gas bubble diffusive growth and its effect on subsequent bubbles

“…More recently, due to new developments in experimental techniques (see e.g. Enríquez et al 2014) and new applications, such as energy generation by chemical reactions (Oehmichen, Datsevich & Jess 2010), the topic has been the object of renewed attention.…”

“…The dynamical equation (1.1) needs to be modified when the bubble grows on a solid surface, which changes the boundary conditions to be applied to the solution of the diffusion equation (Stricker et al 2013). Enríquez et al (2014) approximated the effect of the solid surface by introducing the concept of an effective area through which gas 476 Á. Moreno Soto, A. Prosperetti, D. Lohse and D. van der Meer diffuses into the bubble. In their experiment, the bubble grew out of a pit of radius R p on the solid surface.…”

Growing bubbles and freezing drops: depletion effects and tip singularities

“…Figure 4.2: Dimensionless rate of change of the bubble area, divided by its theoretical (constant) value for a purely diffusive growth regime as a function of x ∼ √ t (eq.4.3). This value is calculated with the correction proposed in [79] to account for the influence of the silicon chip. The leftmost rising part and horizontal plateau of the curves are expected from diffusion-driven growth; the right-hand rising part suggests the influence of convection.…”

“…In [79], we found that the influence of the silicon chip, which acts like an obstacle for mass transfer through part of the bubble area, can be approximated with a correction to the asymptotic solution yieldinḡ…”