On the pressure balance and the resulting phase fraction in compressed multiple emulsions

• Published in: Colloids and surfaces. A, Physicochemical and engineering aspects Physicochemical and engineering aspects, 2017-01, Vol.513, p.196-203
• Main Authors: Beer, Sebastian, Dobler, Dorota, Schmidts, Thomas, Keusgen, Michael, Runkel, Frank
• Format: Article
• Language: English
• Subjects: Compressed emulsion; Confocal microscopy; Disperse phase fraction; Multiple emulsion; Pressure balance; Shrinking; Swelling
• ISSN: 0927-7757; 1873-4359
• DOI: 10.1016/j.colsurfa.2016.10.042

[Display omitted] •The relationship between phase fractions and pressure gradients in multiple emulsions is quantified.•A method to determine the disperse phase fraction is developed and presented.•Based on the measured disperse phase fraction, the encapsulation efficiency is determined.•The formation of compressed multiple emulsion during production is analysed. While swelling and shrinking of multiple emulsions – depending on existing pressure gradients – has been well reported in the literature, little research has been carried out covering the osmotic equilibration between pressure systems caused by interfacial phenomena and phase fractions for multiple emulsions in which either one or both disperse phases exhibit a phase fraction above the maximum packing limit without any deformation of the droplets. In this paper, a model for determining the theoretical equilibrium state regarding osmotic regulation is presented, as well as a new experimental method to determine the disperse phase fraction. This method is employed to compare the measured phase fractions to the theoretical predictions. Using both experimental and theoretical approaches, a direct method is proposed to define the disperse phase fraction and the encapsulation efficiency, yielding potential for a knowledge driven improvement of the production of multiple emulsions.