Miniemulsions for the Production of Nanostructured Particles

Nanostructured particles made from polystyrene and zinc oxide are synthesized by precipitation in miniemulsions and miniemulsion polymerization. There are two main applications for miniemulsions: the formation of sub-micron or nano-sized reactors for the precipitation of inorganic nanoparticles and the use of sub-micron or nano-sized droplets as templates for nanostructured particles. The latter includes the formation of the desired structures within a monomer droplet, which then is polymerized without changing its size or structure during the process. In this research article two approaches to combine both processes are presented: The zinc oxide nanoparticles are precipitated in an inverse miniemulsion of water droplets in a continuous monomer phase. The resulting miniemulsion is either distilled and the nanoparticles are forced into the monomer phase or the miniemulsion is used directly without distillation. In both cases the particle loaded monomer droplets are afterwards polymerized to hybrid nanoparticles. The focus is on the technological challenges in producing nano-sized, hybrid particles, especially in regard to continuous processing.