Hydrodynamic Theory for Spontaneously Growing Dimple in Emulsion Films with Surfactant Mass Transfer

Danov, Krassimir D.; Gurkov, Theodor D.; Dimitrova, T.; Ivanov, Ivan B.; Smith, D.

doi:10.1006/jcis.1997.4719

Cited by 35 publications

(23 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the former case the Poiseuille contribution to film drainage, represented by the second term on the right-hand side of [22], becomes negligible and drainage is governed by the interface velocity u * u , which in turn is limited by viscous stresses exerted by the drop phase. This situation of "partial interfacial mobility" is an important one since it constitutes a good approximation in many practical systems (14,16).…”

Section: Governing Equationsmentioning

confidence: 99%

See 1 more Smart Citation

Effect of Insoluble Surfactants on Drainage and Rupture of a Film between Drops Interacting under a Constant Force

Chesters

Bazhlekov

2000

Journal of Colloid and Interface Science

108

View full text Add to dashboard Cite

Section: Governing Equationsmentioning

confidence: 99%

“…The solution scheme for the mathematical model [22][23][24][25][26][27][28][29][30][31][32][33][34] is the same as that used in (16 . A more detailed discussion of the satisfaction of the prescribed force boundary condition can be found at the end of this section.…”

Section: Numerical Schemementioning

confidence: 99%

Effect of Insoluble Surfactants on Drainage and Rupture of a Film between Drops Interacting under a Constant Force

Chesters

Bazhlekov

2000

Journal of Colloid and Interface Science

108

View full text Add to dashboard Cite

“…In that case, the initial distribution of the surfactant between the two phases is a nonequilibrium distribution (10,11). Surfactant initially dissolved in the continuous phase was investigated by Hartland (12), Velev et al (13), and Danov et al (14). They clarified that the Marangoni effect connected with interfacial tension gradients is crucial for conferring emulsion stability.…”

Section: Introductionmentioning

confidence: 97%

Effect of the Dispersion Behavior of a Nonionic Surfactant on Surface Activity and Emulsion Stability

Nakajima

Nabetani

et al. 2001

Journal of Colloid and Interface Science

View full text Add to dashboard Cite

“…Under the action of capillary and disjoining forces the dimple shrinks till the film reaches flat shape at equilibrium. Sometimes, however, under nonequilibrium conditions the dimples can grow driven by external flows [29]. In the frames of the lubrication approximation the evolution of the local thickness H of an axisymmetric wetting film is governed by the following equation [23,30] …”

mentioning

confidence: 99%

“…Due to complexity of this equation it could be solved only numerically [29]. Hereafter we present an approximate procedure for description of the dimple relaxation which elucidates the physical aspects and is more transparent.…”

mentioning

confidence: 99%

Wetting Film Dynamics and Stability

Radoev

Stöckelhuber

Tsekov

et al. 2007

Colloid Stability and Application in Pharmacy

View full text Add to dashboard Cite

Although the wetting films are similar in many aspects to other thin liquid films, there are some differences in their behavior, too. In contrast to soap and emulsion films, whose surfaces are homogeneous, solid substrates of wetting films are heterogeneous as a rule, unless special measures for their homogenization are taken. Here we mean primarily heterogeneous distribution of surface energy leading to existence of hydrophobic domains on hydrophilic surfaces and vice versa. As is known, such hydrophobic domains could play the role of gasphase nucleation centers and it is widely accepted nowadays that nano-bubbles can be formed there. The present paper reviews the effect of nano-bubbles adhered at solid surface on stability of wetting films. It is shown that the existence of nano-bubbles is crucial for the lifetime of wetting films. Another peculiarity typical for hydrophobic solid surface, the so-called slippage effect, is also investigated and its contribution to the dispersion equation of capillary waves on wetting films is accounted for.Thin films, the building blocks of dispersed systems, are present mainly in three variants: soap, emulsion and wetting films. There are many equilibrium and dynamic characteristics typical for all these kinds of films, e.g. the surface DLVO forces acting therein, the type of hydrodynamics in the films (the so-called lubrication flow), the equilibrium and stability conditions, film rupture, etc. However, besides their common nature each kind of films mentioned above possesses specific features, which should be taken into account when interpreting the corresponding experimental data and their influence on the behavior of dispersed systems. The subject of this paper is to review some of the peculiarities, related to the rheology, stability and rupture of wetting films. As is shown, all phenomena observed are due to effects characteristic of solid/liquid surfaces. A section is devoted to the hydrodynamics of wetting films with special attention paid to a new experimental method for exciting and measuring surface waves on wetting films. Among the most interesting results obtained by this method is the anomalous high slippage observed on solid surfaces. Presence of nano-bubbles adhered at solid/liquid surface is suggested as a possible origin of this effect. The idea of the existence of nano-bubbles in wetting films appears again in the last section as a cause for the film rupture. The detailed analysis shows that the region above a nano-bubble resembles more a foam film, which is unstable as a rule, thus explaining why wetting films with repulsive interactions could also rupture.

show abstract

Hydrodynamic Theory for Spontaneously Growing Dimple in Emulsion Films with Surfactant Mass Transfer

Cited by 35 publications

References 16 publications

Effect of Insoluble Surfactants on Drainage and Rupture of a Film between Drops Interacting under a Constant Force

Effect of Insoluble Surfactants on Drainage and Rupture of a Film between Drops Interacting under a Constant Force

Effect of the Dispersion Behavior of a Nonionic Surfactant on Surface Activity and Emulsion Stability

Wetting Film Dynamics and Stability

Contact Info

Product

Resources

About