Acoustically Active Antibubbles

Kotopoulis, Spiros; Johansen, Kristoffer; Gilja, Odd Helge; Poortinga, AT Albert; Postema, Michiel

doi:10.12693/aphyspola.127.99

Cited by 20 publications

(28 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Below this ratio, the harmonic component was too small to be detected. Examples of numerical simulations of the acoustic response from bubbles and antibubbles without an encapsulating shell have also been presented in [7], indicating a significant higher harmonic content of antibubbles compared to conventional bubbles.…”

Section: L Gmentioning

confidence: 99%

Harmonic response from microscopic antibubbles

et al. 2018

View full text Add to dashboard Cite

An antibubble is a gas bubble containing a liquid droplet core. Both the droplet and the gas bubble are typically surrounded by stabilising shells. Owing to electrostatic forces exerted by these shells, core droplets of micrometer diameter do not readily coalesce with the surrounding liquid medium. Owing to the incompressibility of the liquid droplet core, antibubbles will oscillate asymmetrically, i.e., the radial excursion amplitude of the surface is greater during expansion than during contraction, when subjected to diagnostic ultrasound. Consequently, the harmonic content of the ultrasound signal radiated from antibubbles must be higher that that from identical bubbles without a liquid core. Whether the harmonic signal component generated by physical antibubbles is higher than the harmonic component of identical bubbles without a core has been studied here. We subjected prefabricated antibubbles and identical bubbles without core droplets to 1-MHz ultrasound and to a commercial ultrasound system, and recorded the spectra with a broadband transducer oriented perpendicularly to the transmitter. Normalised by the acoustic response from the medium, the antibubble signal shows stronger higher harmonics than the reference signal, and negligible fundamental response. In conclusion, antibubbles are suitable candidates for harmonic imaging. The generation of higher harmonics without fundamental has been attributed to asymmetric antibubble expansion.

show abstract

Section: L Gmentioning

confidence: 99%

Harmonic response from microscopic antibubbles

et al. 2018

View full text Add to dashboard Cite

show abstract

“…Noticeably, it has recently been suggested that leaks from subsea hydrocarbon production facilities contain antibubbles with a specific acoustic signature [5]. Nowadays, benefiting from the development of microfluidics, several potential applications have arisen, such as using antibubbles as contrast agent for enhancing ultrasonic imaging [6,7] or loading the antibubble core with a ferrofluid to serve as a vehicle for magneto-controlled drug delivery [8].…”

Section: Introductionmentioning

confidence: 99%

Controlling the lifetime of antibubbles

Vitry

Dorbolo

Vermant

et al. 2019

Advances in Colloid and Interface Science

View full text Add to dashboard Cite

An antibubble is a liquid droplet wrapped by a thin layer of gas, inside a bulk liquid usually of the same composition. The lifetime of an antibubble is governed by the drainage of the gas between the two liquid-gas interfaces populated by surfactants. Depending on the relative magnitude of surface viscosity and elastic moduli, which directly depend on or are determined by the nature of surfactants, the lifetime of an antibubble may vary a lot, from few seconds to few minutes. While such a difference can be predicted with models that include the role of interfacial properties, they were not observed experimentally in previous studies, due to important sources of dispersion. In this review, the main sources of dispersion are identified, such as (i) the initial amount of gas embedded in the antibubble, (ii) the level of saturation of gas in the bulk liquid, (iii) the presence of dust particles (b0.5 μm) in the gas, and (iv) three-dimensional flow effects. By accounting for these various effects, we obtain a coherent view on the lifetime of an antibubble, as a function of its radius and the surface rheology, with excellent consistency between experiments and modeling. Results thus demonstrate that controlling the size and lifetime of antibubbles is achievable.

show abstract

“…Since antibubbles have spherical symmetry and might be expected to undergo breathing mode oscillations analogous to those described by the Rayleigh-Plesset equation, a first approximation to an antibubble acoustical model can be made using some minor modifications to this wellestablished model for normal bubbles. We note that Kotopoulis et al 34 derived a version of the Rayleigh-Plesset equation for antibubbles from first principles, but we will outline another model here, which includes some empirical components, for reasons that are discussed below.…”

Section: Modification Of the Rayleigh-plesset Equation For Antibubmentioning

confidence: 99%

The acoustical signals produced by antibubble formation

Naghavi

Czerski

2018

The Journal of the Acoustical Society of America

View full text Add to dashboard Cite

An antibubble is an unusual object: a submerged water drop encapsulated in a thin shell of air that is stable underwater for 10-100 s. They are often thought of as the inverse of a soap bubble because they are a spherical shell of air in water in contrast to a shell of water in air. Antibubbles may be formed when water droplets impact the surface of surfactant-covered water, within a limited range of drop radius and drop impact velocity. In this paper, the range of drop size and impact velocity over which large antibubbles (radius 1-3 mm) are generated by the impact of falling drops is characterised, and the relationship of these parameters to the size of the antibubble formed is shown. Measurements of the two acoustical signals that may be produced as an antibubble is formed by drop impact are reported, and their relationship to the antibubble radius and shell thickness is established. Acoustical measurements taken are interpreted in the context of a modified Rayleigh-Plesset equation that provides a good fit to the frequency data for air shells greater than 100 μm in thickness. However, these results highlight the need for future work on the damping mechanisms associated with these larger antibubbles.

show abstract

Acoustically Active Antibubbles

Cited by 20 publications

References 10 publications

Harmonic response from microscopic antibubbles

Harmonic response from microscopic antibubbles

Controlling the lifetime of antibubbles

The acoustical signals produced by antibubble formation

Contact Info

Product

Resources

About