Wetting-induced formation of controllable monodisperse multiple emulsions in microfluidics


Deng, N. - N. ; Wang, W. ; Ju, X. - J. ; Xie, R. ; Weitz, D. A. ; Chu, L. - Y. Wetting-induced formation of controllable monodisperse multiple emulsions in microfluidics. Lab on a Chip 2013, 13, 4047-4052. Copy at http://www.tinyurl.com/mvxu5f8
2013_chu_labchip.pdf852 KB


Multiple emulsions, which are widely applied in a myriad of fields because of their unique ability to encapsulate and protect active ingredients, are typically produced by sequential drop-formations and drop-encapsulations using shear-induced emulsification. Here we report a qualitatively novel method of creating highly controlled multiple emulsions from lower-order emulsions. By carefully controlling the interfacial energies, we adjust the spreading coefficients between different phases to cause drops of one fluid to completely engulf other drops of immiscible fluids; as a result multiple emulsions are directly formed by simply putting preformed lower-order emulsion drops together. Our approach has highly controllable flexibility. We demonstrate this in preparation of both double and triple emulsions with a controlled number of inner drops and precisely adjusted shell thicknesses including ultra-thin shells. Moreover, this controllable drop-engulfing-drop approach has a high potential in further investigations and applications of microfluidics. Importantly, this innovative approach opens a window to exploit new phenomena occurring in fluids at the microscale level, which is of great significance for developing novel microfluidics.


Times Cited: 0

Last updated on 05/11/2014