ISSN:
1089-7666
Source:
AIP Digital Archive
Topics:
Physics
Notes:
This paper is principally concerned with the production of emulsion droplets (water in oil) by a continuous process that exploits hydrodynamic instability phenomena. This is done by utilizing the characteristic isotropic turbulence, which can be set up in a tube, duct, or nozzle. Studies completed have focused on the prediction and experimental verification of the creation of water-in-oil emulsion droplets, of diameter D in the range 0.5≤D≤10 μm, whereby an aqueous phase-oil phase system is formed into a stabilized emulsion. This is achieved using a novel mixing technique that hydrodynamic instabilities in the form of "Kolmogorov'' isotropic, turbulent fluid eddies whose size scale λK, frequency of occurrence fK, and fluctuating velocity u˜' are readily defined in both numerical and physical terms. Results from this work will be discussed, including the generation of scale-up rules for such systems in terms of geometry and fluid flow velocities that yield continuous emulsions. In particular, the effect of the fluid–fluid and interface variables interfacial tension γi, and dispersed phase viscosity ηd, will be highlighted in relation to the prediction of emulsion droplet size dd, and distribution n[dd], σSD. A major conclusion from our work is that the role of fluid dynamics in interfacial phenomena, such as the creation of stable dispersions, is much more important than chemists would have us believe!
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.857991
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