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Home List of Titles Homo- and hetero-interactions between air bubbles and oil droplets measured by atomic force microscopy
Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/206352
- Homo- and hetero-interactions between air bubbles and oil droplets measured by atomic force microscopy
- Tabor, Rico F.; Wu, Chu; Lockie, Hannah; Manica, Rogerio; Chan, Derek Y. C.; Grieser, Franz; Dagastine, Raymond R.
- The atomic force microscope was used to analyse the interactions between bubbles and oil droplets in surfactant-free aqueous solutions. Both homo- (bubble-bubble and drop-drop) and hetero- (bubble-drop) interactions were examined to elucidate the role of colloidal and hydrodynamic forces which, together with interfacial deformations dictate the stability in these systems. It is shown that electrical double-layer forces can be rendered attractive within a small pH range, and that the Van der Waals force can be switched from attractive to repulsive by material choice and ionic strength through salt effects on the so-called 'zero-frequency' term of the Lifshitz theory. By measuring interaction events between bubbles and drops at higher velocities, it is seen that deformation of the bodies and lubrication in the film generated between them can be predicted with a continuum hydrodynamic theory. These results suggest that solution pH and droplet material choice can be used to enhance or inhibit coalescence in such multi-component and multi-phase systems, and this may prove useful in controlling the behaviour of systems in microfluidics, as well as dispersion and formulation science.
- Publication type
- Journal article
- Soft Matter, Vol. 7, no. 19 (2011), pp. 8977-8983
- Publication year
- FOR Code(s)
- 02 Physical Sciences; 03 Chemical Sciences; 09 Engineering
- Air bubbles; Atomic force microscopy; Hetero-interactions; Homo-interactions; Oil droplets
- Royal Society of Chemistry
- Publisher URL
- Copyright © 2011.
- Peer reviewed