Capillarity-controlled entrainment of liquid by a thin cylindrical filament moving through an interface
✍ Scribed by B.J. Carroll; J. Lucassen
- Publisher
- Elsevier Science
- Year
- 1973
- Tongue
- English
- Weight
- 714 KB
- Volume
- 28
- Category
- Article
- ISSN
- 0009-2509
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✦ Synopsis
A theory is presented predicting the thickness of liquid lilms formed in withdrawal experiments with thin cylinders. If gravity can be neglected, an analogy exists with the thinning process of small soap tilms by capillary suction. Based on this analogy a theory has been derived predicting film thickness to be proportional to the square root of the withdrawal speed and of the viscosity and inversely proportional to the square root of the interfacial tension.
Withdrawal experiments carried out in an oil-water system at varying speed and inter-facial tension continned this theory. In the presence of surfactant the interface resists extension and tilm thicknesses -under otherwise equal conditions-were found to be about 60 per cent higher than in the absence of surfactant. The importance of surface dilational properties on formation of liquid cylinders and cylindrical films and the relevance to emulsification is discussed qualitatively.