Stabilization of thin liquid films by repulsive van der waals force
KAUST DepartmentClean Combustion Research Center
High-Speed Fluids Imaging Laboratory
Mechanical Engineering Program
Physical Science and Engineering (PSE) Division
Online Publication Date2014-05-02
Print Publication Date2014-05-13
Permanent link to this recordhttp://hdl.handle.net/10754/563545
MetadataShow full item record
AbstractUsing high-speed video recording of bubble rise experiments, we study the stability of thin liquid films trapped between a rising bubble and a surfactant-free liquid-liquid meniscus interface. Using different combinations of nonpolar oils and water that are all immiscible, we investigate the extent to which film stability can be predicted by attractive and repulsive van der Waals (vdW) interactions that are indicated by the relative magnitude of the refractive indices of the liquid combinations, for example, water (refractive index, n = 1.33), perfluorohexane (n = 1.23), and tetradecane (n = 1.43). We show that, when the film-forming phase was oil (perfluorohexane or tetradecane), the stability of the film could always be predicted from the sign of the vdW interaction, with a repulsive vdW force resulting in a stable film and an attractive vdW force resulting in film rupture. However, if aqueous electrolyte is the film-forming bulk phase between the rising air bubble and the upper oil phase, the film always ruptured, even when a repulsive vdW interaction was predicted. We interpret these results as supporting the hypothesis that a short-ranged hydrophobic attraction determines the stability of the thin water film formed between an air phase and a nonpolar oil phase. © 2014 American Chemical Society.
SponsorsE.Q.L. is grateful for a SABIC Postdoctoral Fellowship. This work is supported in part by an Australian Research Council Discovery Project Grant to D.Y.C.C.
PublisherAmerican Chemical Society (ACS)
- van der Waals interaction between internal aqueous droplets and the external aqueous phase in double emulsions.
- Authors: Wen L, Cheng J, Zou H, Zhang L, Chen J, Papadopoulos KD
- Issue date: 2004 Sep 14
- Measuring forces and spatiotemporal evolution of thin water films between an air bubble and solid surfaces of different hydrophobicity.
- Authors: Shi C, Cui X, Xie L, Liu Q, Chan DY, Israelachvili JN, Zeng H
- Issue date: 2015 Jan 27
- Interactions in lipid stabilised foam films.
- Authors: Toca-Herrera JL, Krasteva N, Müller HJ, Krastev R
- Issue date: 2014 May
- Anomalous pH dependent stability behavior of surfactant-free nonpolar oil drops in aqueous electrolyte solutions.
- Authors: Clasohm LY, Vakarelski IU, Dagastine RR, Chan DY, Stevens GW, Grieser F
- Issue date: 2007 Aug 28
- What do a foam film and a real gas have in common?
- Authors: Stubenrauch C
- Issue date: 2005 Jan