Fabrication of hierarchical microparticles by depositing the in situ synthesized surface nanoparticles on microspheres during the seed emulsion polymerization

► General strategy for the synthesis of hierarchical microparticles is proposed. ► Monomer miniemulsion is added during the seed emulsion polymerization. ► Hierarchical microparticles containing 20-36 nm surface nanoparticles are synthesized. ► Advantages including well-control and convenience are demonstrated.