Figure 1: Particles fabrication principle.
Schematic diagram showing the synthetic steps involved in the preparation of particles with various types of protrusions and cavities. (a) Spherical PS seeds are encapsulated into polymerizable oil droplets via a seeded dispersion polymerization (step 1). Depending on the PS surface charge, the seeds can sit at the oil–water interface (negatively charged seeds, (a)) or be entirely engulfed in the oil (positively charged seeds, (b)). The oil is then hardened via a radical polymerization (step 2) to obtain particles with a protrusion. These colloids can be further processed to selectively dissolve the original seeds and obtain particles with well-defined cavities (step 3). False-colour scanning electron microscopy images highlight the seeds in red and the polymerized oil in green. A bright field microscopy image of unpolymerized composite particles is also shown in (b). Scale bars, 2 μm.
