Electrohydrodynamic Instabilities in Free Emulsion Films

Abstract

Electrohydrodynamic instabilities were induced in thin water-in-oil emulsion films by application of external DC electric field. The dominant wavelengths of instabilities were measured for constant electric fields of various strengths. The dominant wavelengths agreed reasonably well with theoretical predictions based on a linear stability model. The linear stability model used in this study took into account experimentally measured repulsive disjoining pressure and calculated Maxwell stress. The observation of such instabilities can help to understand the rupture mechanism of emulsion films under the influence of electric field.

Keywords

• electrohydrodynamic instabilities
• water-in-oil emulsion films
• electrocoalescence
• linear stability model
• thin film breakdown