Preparation Of Oxide Nanoring Based On Polystyrene Nanosphere Template

In the recent years, various nanoring-structures have aroused great excitement due to their novel physical and chemical properties as well as potential applications in future nanodevices. Several techniques have been employed to fabricate the nanorings including metal, and inorganic and organic compound. However, the established techniques seem to have technologic and economic limits. In this paper, we develop a new method to synthesize TiO₂ and SiO₂ nanoring structures by using polystyrene (PS) nanospheres as template, which can be performed under a milder chemical condition.1. The PS nanospheres were prepared by micro-emulsion polymerization. And the appropriate emulsifier was choosen. The diameter of the PS nanospheres is related to the emulsifier concentration in the emulsion. The more the emulsifier is added, the smaller of the PS diameter is. As the molor ratio of styrene monomer and emulsifier is between 180 and 270, the average diameter of the PS nanosphere is adjusted in the range of 80-160nm.2. TiO₂ sol was prepared by sol-gel method. Then TiO₂ sol was mixed with PS emulsion. In the mixture, PS nanosphere acted as template. The influence of experimental conditions on the preparation of TiO₂ nanorings was investigated. Then the optimum conditions of preparing TiO₂ nanoring successfully were obtained. The resultant TiO₂ nanorings were characterized by Field-Emission Scanning Electron Microscopy (FE-SEM), X-Ray Diffraction (XRD), Energy Dispersive Spectrometry (EDS) and Atomic Force Microscope (AFM). FE-SEM results show that the inner diameter of TiO₂ nanoring is matched with that of PS nanospheres. XRD result indicates that the TiO₂ nanorings were poly-crystalline with anatase structure.3. The SiO₂ nanorings were prepared based on PS nanospheres template whose procedure is similar to that of the TiO₂ nanorings. And the effect of experimental conditions on the SiO₂ nanoring structure was primarily studied.