Osmolarity-controlled swelling behaviors of dual-cored double-emulsion drops

• DOI: 10.1007/s10404-017-1897-4
• Publication Date: 2017-03-17T03:56:43Z
• Authors: Likai Hou; Yukun Ren; Yankai Jia; Xiaoming Chen; Xiaokang Deng; Zheng Tang; Qingming Hu; Ye Tao; Hongyuan Jiang
• Keywords: Coalescence (physics); Swell

We report osmolarity-controlled swelling behaviors of dual-cored water-in-oil-in-water (W/O/W) double-emulsion drops, which are caused by the discrepancy of salt concentration of the inner cores and suspending medium. The expanding speed and resultant size can be manipulated independently according to salt concentration. The swelling behaviors result in two kinds of transformation in the emulsion drops. One is coalescence of the two inner aqueous cores, taking place when the cores are of the same salt concentrations and the double-emulsion drops swell to dumbbell-shaped morphology. Another is rupture of one inner core, which happens when the cores are of different salt concentrations and the double-emulsion drops swell to snowman-shaped structures. The conditions for core-coalescence and core-rupture are investigated, respectively. The swelling leading transformation of emulsion drops are of promising application as microreactors and tiny vesicles: The core-coalescence can lead to controlled reaction of two solvents while protecting the reaction form external contamination; the core-rupture may be utilized for targeted release of reagents at specific position.