Antibubble lifetime: Influence of the bulk viscosity and of the surface modulus of the mixture

Abstract

a b s t r a c tLifetime of antibubbles has been measured for different liquid mixtures. The life duration of an antibubble is governed by the air drainage from the bottom to the top of the antibubble. We show that their lifetime is influenced by both bulk and surface properties of the liquid mixture used to create the antibubble. When the viscosity is increased, the stability of the antibubbles during the first seconds of their life is enhanced. By changing the surface modulus by a factor 100, the mean antibubble lifetime is doubled. Surfactants can affect the mobility of the film surface and, thereby, the rate of air film thinning.

Antibubble Dynamics: The Drainage of an Air Film with Viscous Interfaces

“…The fact that there are 2 orders of magnitude between the corresponding surface dilatational viscosities [16], excludes the possibility that dilational effects can rationalize the experimental observations of Ref. [10]. This conclusion is also supported by experiments on antibubbles with other surfactant mixtures as also reported in Table I.…”

“…For instance, the great difficulty to generate antibubbles with sodium dodecyl sulfate (SDS) solutions is mentioned in Ref. [10]. Accordingly, surface shear viscosity for SDS solutions at concentrations much above the critical micelle concentration (CMC) is of the order of 10 À3 mPa Á s Á m, which, following our present model, gives lifetimes of the order of 0:68 AE 0:32 s, indeed too small to observe any antibubble experimentally.…”

“…The experimental lifetimes reported in Table I correspond to the largest values measured for each mixture in Ref. [10]. The longest lifetime corresponds to the thinnest critical film thickness whose value should thus be the closest to the critical film thickness triggered by van der Waals forces, which enables a comparison with our calculations.…”

“…Therefore, in the remainder of this Letter and for comparison with experiment, we only consider the RS2, which has the advantage to remove the arbitrary parameter h c of the RS1, which was considered for general purpose and comparison with other theoretical results for critical thicknesses [11]. We consider the experimental data by Dorbolo et al [10] who used mixtures composed of 0.33 wt % SLES þ 0:17 wt% CAPB (þ 0:02 wt% MAc) [15]. These mixtures have both a strong surface modulus and fast adsorption kinetics [16].…”

“…Given the wide dispersion of experimental lifetimes, for which the standard deviation can be as large as the mean value [10], we consider two rupture scenarios (RSs). In the RS1 the antibubble dies when the minimum film thickness h min reaches a critical thickness h c (see, e.g., Ref.…”