Synthesis of atypical nanoparticles by the nanostructure in thin films of triblock copolymers.

We report the synthesis of atypical nanoparticles in donut shape with or without additional spherical nanoparticles attached on them by using the donut-like nanostructure formed in a thin film of triblock copolymers. In a high-humidity condition, a spin-coated film of triblock copolymer had donut-like holes consisting of the periphery and the center. By selective coordination of precursors of nanoparticles to the periphery of the holes, donut-like oxide nanoparticles were synthesized by oxygen plasma treatment on the film.