DWI - Leibniz-Institute for Interactive Materials e.V., Institute for Technical and Macromolecular Chemistry of RWTH Aachen University, Forckenbeckstrasse 50, 52056, Aachen, Germany.
Nat Commun. 2018 May 15;9(1):1918. doi: 10.1038/s41467-018-04320-7.
Double emulsions are complex fluid systems, in which droplets of a dispersed liquid phase contain even smaller dispersed liquid droplets. Particularly, water-in-oil-in-water double emulsions provide significant advantages over simple oil-in-water emulsions for microencapsulation, such as carrier of both aqueous and oily payloads and sustained release profile. However, double emulsions are thermodynamically unstable systems consisting typically of relatively large droplets. Here we show that nanoscale water-in-oil-in-water double emulsions can be prepared by adding a silica precursor polymer, hyperbranched polyethoxysiloxane, to the oil phase without any additional surfactants. The resulting double miniemulsions are transformed to robust water@SiO@polymer@SiO nanocapsules via conversion of the precursor to silica and polymerization of the oil phase. Other intriguing nanostructures like nanorattles and Janus-like nanomushrooms can also be obtained by changing preparation conditions. This simple surfactant-free double miniemulsion polymerization technique opens a promising avenue for mass production of various complex hybrid nanostructures that are amenable to numerous applications.
双乳液是复杂的流体体系，其中分散液相的液滴中甚至包含更小的分散液滴。特别是，水包油包水双乳液在微胶囊化方面比简单的油包水乳液具有显著的优势，例如可以作为水相和油相载物的载体，以及可以实现持续释放的特性。然而，双乳液是热力学不稳定的体系，通常由相对较大的液滴组成。在这里，我们表明可以通过向油相添加硅烷前体聚合物——超支化聚乙氧基硅氧烷，而无需任何额外的表面活性剂，来制备纳米级的水包油包水双乳液。通过将前体转化为二氧化硅并聚合油相，所得的双亚微乳液转化为坚固的水@SiO@聚合物@SiO 纳米胶囊。通过改变制备条件，还可以得到其他有趣的纳米结构，如纳米摇瓶和类 Janus 纳米蘑菇。这种简单的无表面活性剂双亚微乳液聚合技术为大规模生产各种复杂的混合纳米结构开辟了一条有前途的途径，这些纳米结构适用于许多应用。
