Diblock Copolymer Reverse Micelles as Nanoscale Reactors for Zinc Oxide Nanoparticles

Their potential for blue-light source applications underscores the technological attraction of ZnO nanoparticles. However, the degree of blue-shift in their absorption edge scales with particle size, so the narrow bandwidth requirement places a strict demand for monodispersity in the nanoparticle population size distribution. Thus in the last decade, the use of diblock copolymer micelles in the synthesis of different metallic and semiconductor nanoparticles has become increasingly common, in part because the yield is reasonably monodisperse. In the study that we are presenting, zinc oxide nanoparticles were synthesized inside polystyrene-b-poly2vinlpyridine (PS-b-P2VP) micelles in toluene using zinc acetate and tetra methyl ammonium hydroxide (TMAH) as reactants. The UV-visible absorption spectra of the solutions showed a peak with an onset around 340 nm, indicating the presence of ZnO nanoparticles. Comparison with reference solutions also suggests the presence of zinc oxide in the material system. To prove that these did indeed form inside the micelles, the system was extensively studied by phase and topographical imaging using tapping mode atomic force microscopy, by dynamic light scattering, and by high angle annular dark field imaging in a scanning transmission electron microscope, and these results would be presented as well