Opalski Adam S, Makuch Karol, Derzsi Ladislav, Garstecki Piotr
Institute of Physical Chemistry of Polish Academy of Sciences Kasprzaka 44/52 01-224 Warsaw Poland
RSC Adv. 2020 Jun 16;10(39):23058-23065. doi: 10.1039/d0ra03007d.
We investigate the role of viscosities on the formation of double emulsion in a microfluidic step emulsification system. Aqueous droplets of various viscosities and sizes were engulfed in fluorocarbon oil and subsequently transformed into double droplets in the microfluidic step emulsifying device. We identify two distinct regimes of double droplet formation: (i) core droplets split into multiple smaller droplets, or (ii) cores slip whole into the forming oil shell. We show that the viscosity ratio of the core and shell phases plays a crucial role in determining the mode of formation of the double emulsions. Finally, we demonstrate that high viscosity of the core droplet allows for generation of double emulsions with constant shell thickness for cores of various sizes.
我们研究了在微流控分步乳化系统中粘度对双乳液形成的作用。各种粘度和尺寸的水滴被氟碳油包裹，随后在微流控分步乳化装置中转变为双滴。我们确定了双滴形成的两种不同模式：（i）核心液滴分裂成多个较小的液滴，或（ii）核心整体滑入正在形成的油壳中。我们表明，核心相和壳相的粘度比在决定双乳液的形成模式中起着关键作用。最后，我们证明，对于各种尺寸的核心，核心液滴的高粘度允许生成具有恒定壳厚度的双乳液。
