Chemosensors (Nov 2022)

Measurement of the Filling Degree and Droplet Size of Individual Double Emulsion Droplets Using Raman Technologies

  • Thomas Hufnagel,
  • Richard Stoy,
  • Matthias Rädle,
  • Heike P. Karbstein

DOI
https://doi.org/10.3390/chemosensors10110463
Journal volume & issue
Vol. 10, no. 11
p. 463

Abstract

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Double emulsions arouse great interest in various industries due to their ability to encapsulate value-adding ingredients. However, they tend to be unstable due to their complex structure. Several measurement techniques have already been developed to study and monitor the stability of double emulsions. Especially for the measurement of the filling degree of double emulsions, so far there is no reliable method available. In this paper, a measurement system is presented that can measure the filling degree of water-in-oil-in-water (W/O/W) double emulsions by both spectrometrical and photometrical means. The method is based on the Raman effect and does not require any sample preparation, and the measurement has no negative influence on the double emulsion. It is shown that both spectrometric and photometric Raman techniques can reliably distinguish between double emulsions with filling degrees that have a 0.5% difference. Additionally, oil droplet sizes can be photometrically measured. Furthermore, the measurement system can be integrated into both inline and online emulsification processes.

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