Synthesis of polystyrene@silica@organosilica hierarchical hybrid particles through seeded emulsion polymerization

Abstract

We reported the synthesis of hierarchical polystyrene@silica@organosilica hybrid particles with different morphologies via seeded emulsion polymerization. Series of organosilica seeds with different core@shell morphologies were first synthesis through the same biphasic sol-gel methods incorporation with a Pickering process. For the Pickering process, tiny silica particles (15 nm) were first formed and then used to stabilize 3-(methacryloxy)propyl trimethoxy silane (γ-MPS) droplets. Various amount of tetraethyl orthosilicate (TEOS) was then delivered in to the aqueous solution carefully to form a biphasic system and formed seeds with different core@shell structures when the up layer disappeared. For the seeded emulsion polymerization, the virous morphologies of the seeds induced different surface hydrophilicity which lead to different monomer swelling process before polymerization, and further result in the different morphologies of the final hybrid particles. Hybrid particles with multi-pod core@shell, watermelon-like, worm-like and daisy-like morphologies were achieved in this work. These hybrid particles with soft organosilica inner core, hard silica interlayer and polymer shell may have important applications in coating, printing, sensors, drug encapsulation and many related materials science areas.