title: Ultrahigh density arrays of toroidal ZnO nanostructures by one-step cooperative self-assembly processes: mechanism of structural evolution and hybridization with Au nanoparticles.
abstract: A quick protocol for the fabrication of ultrahigh density arrays of toroidal ZnO nanostructures with tailored structures on a substrate surface is presented based on the one-step spin coating of a common solution composed of inverse micelles of polystyrene-block-poly(4-vinyl pyridine) copolymers (PS-b-P4VP) and sol-gel precursors without the need of conventional complex lithographic techniques. ZnO toroids decorated with gold nanoparticles are also obtained by subsequent loading and reduction of metallic precursors. It was elucidated that the diethanolamine moiety in the sol-gel precursors, which induces selective swelling and structural reorganization of the P4VP core blocks, plays a key role in the generation of toroidal nanostructures. Toroidal ZnO nanostructures embedded in a PS-b-P4VP matrix films or arrays of pure wurtzite ZnO nanorings are obtained by calcination under inert atmosphere. The structural parameters of the toroidal nanostructures such as the width, height, diameter of the rims as well as the spacing of their 2D arrays are controlled by employing PS-b-P4VP with different molecular weight and varying the mixing protocols.
authors.affiliation: Department of Chemistry and Nano Science, Ewha Womans University, 11-1 Daehyun-dong, Seodaemun-gu, Seoul 120-750, Korea.
authors.forename: Yoon Hee
authors.initials: YH
authors.lastname: Jang
authors.forename: Seung Yun
authors.initials: SY
authors.lastname: Yang
authors.forename: Yu Jin
authors.initials: YJ
authors.lastname: Jang
authors.forename: Cheolmin
authors.initials: C
authors.lastname: Park
authors.forename: Jin Kon
authors.initials: JK
authors.lastname: Kim
authors.forename: Dong Ha
authors.initials: DH
authors.lastname: Kim