Physical Chemistry I, Bayreuth University, Universitätsstrasse 30, D-95447, Bayreuth, Germany.
Lab Chip. 2011 Sep 21;11(18):3188-92. doi: 10.1039/c1lc20242a. Epub 2011 Jul 27.
Double emulsions are valuable structures that consist of drops nested inside bigger drops; they can be formed with exquisite control through the use of droplet-based microfluidics, allowing their size, composition, and monodispersity to be tailored. However, only little control can be exerted on the morphology of double emulsions in their equilibrium state, because they are deformable and subject to thermal fluctuations. To introduce such control, we use droplet-based microfluidics to form oil-in-water-in-oil double emulsion drops and arrest their shape by loading them with monodisperse microgel particles. These particles push the inner oil drop to the edge of the aqueous shell drop such that the double emulsions adopt a uniform arrested, anisotropic shape. This approach circumvents the need for ultrafast polymerization or geometric confinement to lock such non-spherical and anisotropic droplet morphologies. To demonstrate the utility of this technique, we apply it to synthesize anisotropic and non-spherical polyacrylate-polyacrylamide microparticles with controlled size and shape.
双乳液是一种由内部嵌套的液滴组成的有价值的结构；通过使用基于液滴的微流控技术，可以对其进行精密控制，从而可以定制其大小、组成和单分散性。然而，在双乳液的平衡状态下，对其形态的控制能力非常有限，因为它们是可变形的，并且受到热涨落的影响。为了引入这种控制，我们使用基于液滴的微流控技术来形成油包水包油双乳液滴，并通过加载单分散微凝胶颗粒来固定它们的形状。这些颗粒将内油滴推到水壳滴的边缘，从而使双乳液采用均匀的、各向异性的形状。这种方法避免了使用超快聚合或几何约束来锁定这种非球形和各向异性的液滴形态的需要。为了展示这项技术的实用性，我们将其应用于合成具有可控尺寸和形状的各向异性和非球形聚丙烯酸酯-聚丙烯酰胺微颗粒。
