Facile fabrication of snowman-like Janus particles with asymmetric fluorescent properties via seeded emulsion polymerization

This paper presents a facile method for the preparation of snowman-like Janus particles (SJP) with asymmetric fluorescent property via seeded emulsion polymerization, in which in situ formed raspberry-like cadmium sulfide/poly(styrene–divinylbenzene–acrylic acid) nanocomposite particles (RNP) were used as the seeds. The as-prepared RNP and SJP have been thoroughly characterized by transmission electron microscopy, field-emission scanning electron microscopy, thermogravimetric analysis, X-ray powder diffraction, Fourier transform infrared, ultraviolet visible, and photoluminescent spectrometry. It is found that the size ratio of the polymer bulge/inorganic seed part could be continuously tuned as well as the composition of polymer bulges by changing the composition of monomer mixtures and monomer/seed weight ratio. The obtained Janus particles possess amphiphilic properties which can be further used as solid surfactants to stabilize W/O emulsions and successively to construct hierarchical structured materials. Meanwhile, their asymmetric fluorescent properties may be exploited to detect their assembled situation and orientation at the oil–water interface of emulsions as well as at the surface of hierarchical structured materials.