Surfactant effects on mass transfer from drops subject to interfacial instability

Beitel, Allan; Heideger, W. J.

doi:10.1016/0009-2509(71)86015-3

Cited by 54 publications

(17 citation statements)

References 16 publications

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“…The magnitude of contamination is described by the polar angle θ cap of the spherical coordinate system with z ‐axis coinciding with the direction of the relative motion of the bubble or drop in the fluid. These model predictions are in good agreement with the experimental observations of several authors17–23 who reported the formation of a stagnant cap at the rear of a drop or a bubble contaminated with slightly soluble surfactant (high Peclet numbers). The case of the creeping flow (Stokes flow) past bubbles with stagnant cap has also been investigated 18, 24–26.…”

Section: Introductionsupporting

confidence: 90%

Mass transfer from a contaminated fluid sphere

et al. 2010

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The unsteady mass transfer from a contaminated fluid sphere moving in an unbounded fluid is examined numerically for unsteady-state transfer. The effect of the interface contamination and the flow regime on the concentration profiles, inside and outside a fluid sphere, is investigated for different ranges of Reynolds number (0 \ Re \ 200) and Peclet number (0 \ Pe \ 10 5 ), viscosity ratio between the dispersed phase and the continuous phase (0 \ j \ 10), and the stagnant-cap angle (0 \ h cap \ 180). It was found that the stagnant-cap angle significantly influences the mass transfer from the sphere to a surrounding medium. For all Peclet and Reynolds numbers and j, the contamination reduces the mass transfer flux. The average Sherwood number increases with an increase of stagnant-cap angle and reaches a maximum equal to the average one for a clean fluid sphere at low viscosity ratio and large Peclet numbers. A predictive equation for the Sherwood number is derived from these numerical results.

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Section: Introductionsupporting

confidence: 90%

Mass transfer from a contaminated fluid sphere

et al. 2010

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“…In fact, the veloc-ity of the interface appears to vanish near the rear stagnation point, forming a stagnant cap over the rear of a drop. Similar observations have been reported by Garner and Skelland (1955), Elzinga and Banchero (196 l), Horton et al ( 1965), and Beitel and Heideger ( 1971). Surfactants are responsible for this behavior, as shown experimentally by Griffith ( 1962).…”

Section: Introductionsupporting

confidence: 87%

The effect of surfactant on the terminal and interfacial velocities of a bubble or drop

Leven

Newman

1976

AIChE Journal

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y y = wall-shearrate A , = eigenvalue = dimensionless mixing cup solute concentration + = distance transverse t o flow = volume fraction of particles Stream functions are derived for a spherical droplet in creeping flow with an arbitrary surface tension gradient a t its interface. The stream functions are used to show theoretically that the terminal velocity is reduced and that the interfacial velocitv is retarded, emeciallv near the rear of the M. DOUGLAS LEVAN and JOHN NEWMAN , I droplet, when a trace of surfactant is present in the exterior phase and when surface aging is controlled by diffusion. SCOPEExperimental investigations of droplet motion in liquid containing a surface active impurity have Shown that, compared to motion in pure liquid, both the terminal Correspondence concerning this paper should be addressed to M. velocity and the interfacial velocity of a droplet are reduced, the latter particularly near the rear of the droplet.Here a theoretical investigation of droplet motion in systems contaminated by surfactant is presented. The ob-

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“…It means that the combined model with the appropriate drop and continuous phase mass transfer coeffi cients predicts a lower overall mass transfer coeffi cient for them and α should be higher. Other parts of the model may have infl uence in this matter, for example Beitel and Heideger (1971) have shown that the drop mass transfer coeffi cient can exceed that predicted by the Handlos and Baron (1957) equation even with surfactant present. For c → d direction, the values of F never reach 1 and the model predicts high values of overall mass transfer coeffi cient even without presence of surfactant.…”

Section: Rementioning

confidence: 99%

A Combined Mass Transfer Coefficient Model for Liquid-Liquid Systems under Simultaneous Effect of Contamination and Agitation

Saien

Barani

2008

Can. J. Chem. Eng.

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The simultaneous effect of contamination and agitation was investigated using a pilot rotating disc contactor and mass transfer in both directions with single drops in the absence of drop break‐up and coalescence. It is ideally required to account for the extent of contamination in a quantitative manner and in both phases with a single parameter. In this work, a combined mass transfer model is applied and an improvement is made using an empirical coefficient and having mathematical consistency. Based on 120 experimental data series obtained for each mass transfer direction, a correlation is proposed for the coefficient of this model.

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Surfactant effects on mass transfer from drops subject to interfacial instability

Cited by 54 publications

References 16 publications

Mass transfer from a contaminated fluid sphere

Mass transfer from a contaminated fluid sphere

The effect of surfactant on the terminal and interfacial velocities of a bubble or drop

A Combined Mass Transfer Coefficient Model for Liquid-Liquid Systems under Simultaneous Effect of Contamination and Agitation

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