Production of high internal phase emulsions using rising air bubbles

Galvin, K. P., Pratten, S. J., Shankar, N. G., Evans, G. M., Biggs, S. R. and Tunaley, D. (2001) Production of high internal phase emulsions using rising air bubbles. Chemical Engineering Science, 56 21-22: 6285-6293. doi:10.1016/S0009-2509(01)00293-7

Author Galvin, K. P.
Pratten, S. J.
Shankar, N. G.
Evans, G. M.
Biggs, S. R.
Tunaley, D.
Title Production of high internal phase emulsions using rising air bubbles
Journal name Chemical Engineering Science   Check publisher's open access policy
ISSN 0009-2509
Publication date 2001-11-01
Sub-type Article (original research)
DOI 10.1016/S0009-2509(01)00293-7
Open Access Status Not yet assessed
Volume 56
Issue 21-22
Start page 6285
End page 6293
Total pages 9
Place of publication Kidlington, Oxford, United Kingdom
Publisher Pergamon Press
Language eng
Abstract High internal phase water in oil emulsions were produced by air sparging the two-phase system. The air sparging provided a mechanism for the incremental addition of the aqueous phase into the oil phase, and in turn the formation of aggregates of the aqueous droplets. Over time, a space-filling network of the droplets developed throughout the whole container. We refer to this critical state as a homogeneous, high internal phase coarse emulsion. Once the coarse emulsion was produced, the air bubbles were forced to perform useful work on the network, causing a refinement in the size of the droplets, with a concomitant increase in the emulsion viscosity. The emulsification process was reliable, however, over only a narrow range of air addition rates. At very low rates, the thin film drainage of the oil from between the aqueous droplets was more extensive, and hence the aqueous droplets coalesced and returned to the lower aqueous zone. At higher rates, the air flow tended to disrupt the droplet network. When expanded metal mesh was inserted into the vessel, with each horizontal layer of mesh separated by 40 mm, the process was found to be significantly more robust. Thus, using higher air rates, it was possible to achieve more than an order of magnitude increase in the emulsification rate. A well-defined coarse emulsion was also generated using gravity, by firstly causing aqueous phase droplets to detach from an upper surface, and secondly sediment to form a bed of droplets below. A given dispersed phase volume fraction was produced by fluidising the bed. Once the required bed concentration was formed, a refined emulsion was readily generated by air sparging.
Keyword Air bubbles
High internal phase
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Non-UQ

Document type: Journal Article
Sub-type: Article (original research)
Collection: School of Chemical Engineering Publications
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Citation counts: TR Web of Science Citation Count  Cited 11 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 11 times in Scopus Article | Citations
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