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Creating nanoscale emulsions using condensation

Ingrid F. Guha, Sushant Anand & Kripa K. Varanasi

Nature Communications 8, Article number: 1371 (2017)


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Chemical engineering Fluids Microfluidics

Received: 04 May 2017 Accepted: 12 September 2017

Published online: 08 November 2017


Abstract

Nanoscale emulsions are essential components in numerous products, ranging from processed foods to novel drug delivery systems. Existing emulsification methods rely either on the breakup of larger droplets or solvent exchange/inversion. Here we report a simple, scalable method of creating nanoscale water-in-oil emulsions by condensing water vapor onto a subcooled oil-surfactant solution. Our technique enables a bottom-up approach to forming small-scale emulsions. Nanoscale water droplets nucleate at the oil/air interface and spontaneously disperse within the oil, due to the spreading dynamics of oil on water. Oil-soluble surfactants stabilize the resulting emulsions. We find that the oil-surfactant concentration controls the spreading behavior of oil on water, as well as the peak size, polydispersity, and stability of the resulting emulsions. Using condensation, we form emulsions with peak radii around 100 nm and polydispersities around 10%. This emulsion formation technique may open different routes to creating emulsions, colloidal systems, and emulsion-based materials.

Acknowledgements

We thank the MIT Energy Initiative for financial support. I.F.G. is grateful for support from the NSF Graduate Research Fellowship Program. S.A. thanks the Society in Science—Branco Weiss Fellowship for financial support. The Biophysical Instrumentation Facility for the Study of Complex Macromolecular Systems (NSF-0070319) is gratefully acknowledged. We thank Dr. Arindam Das for his help with fabricating the sample container and Mr. Hassan Bararnia for assistance with DLS measurements (Supplementary Figs. 5, 6).

Author information

Author notes

Ingrid F. Guha and Sushant Anand contributed equally to this work.

Affiliations

Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA

Ingrid F. Guha

Department of Mechanical & Industrial Engineering, University of Illinois at Chicago, Chicago, IL, 60607, USA

Sushant Anand

Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA

Sushant Anand & Kripa K. Varanasi

Contributions

K.K.V and S.A. conceived the research; S.A., I.F.G., and K.K.V designed the research; I.F.G. and S.A. conducted the research; I.F.G., S.A., and K.K.V. prepared the manuscript.

Competing interests
The authors declare no competing financial interests.

Corresponding authors
Correspondence to Sushant Anand or Kripa K. Varanasi.

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