Janus Particles Templated by Janus Emulsions and Application as Pickering Emulsifier.

Abstract

One-step vibrational mixing has afforded batch-scale preparation of Janus emulsion. Fabrication of Janus particles (JPs) templated by the Janus emulsions was motivated as the topology and composition of the Janus droplets were highly tunable and controllable. Two immiscible polymerizable monomers were introduced as inner phases of Janus emulsion. The advanced geometry of the resultant JPs was easily and precisely controlled from "snowman" to "dumbbell" by adjusting the mass ratio of two oils in initial emulsion. Surface coverage of one lobe to the other was tuned by adjusting the mass ratio of mixed surfactants. Moreover, the size of JPs was able to be extended continuously from hundreds of micrometers to few hundred nanometers while their morphologies remained within all this wide size range. The proposed strategy is a universal technique in the synthesis of a family of composite polymeric JPs with both chemical and shape anisotropy. In addition, the as-generated chemically biphasic JPs were applied as emulsifiers to stabilize Pickering emulsion, and more attractively, emulsion inversion was readily achieved by choosing JPs with different morphologies.