Application of longitudinal wave theory to describe interfacial instability

✍ Scribed by J.H. Gouda; P. Joos

• Publisher: Elsevier Science
• Year: 1975
• Tongue: English
• Weight: 706 KB
• Volume: 30
• Category: Article
• ISSN: 0009-2509
• DOI: 10.1016/0009-2509(75)80022-4

✦ Synopsis

The onset of interfacial instability due to solute transfer between two inmiscible liquid phases can be described as the occurrence of an undamped longitudinal wave at their interface. The damping coefficient of such a wave can be expressed in terms of the properties of the interface and the adjoining bulk phases, and is assumed to equal zero at the onset of instability.

The theory predicts instability under the following conditions: (i) The solute decreases the interfacial tension and transfer proceeds from the more viscous to the less viscous phase. (ii) The solute increases the interfacial tension and transfer proceeds from the less viscous to the more viscous phase. (iii) For a restricted range of the relevant parameters, instability is also expected when the solute increases the interfacial tension and transfer occurs from the more viscous to the less viscous phase.

Predictions made from the theory are in fair agreement with experimental data obtained on two different systems.