Zno Ordered Micro-structure Method

Colloidal crystals which are assembled from monodisperse colloidal particles have ordered periodic structures. As colloidal particles are in a periodic array, Colloidal crystals have a broad application prospect in photonic crystals, optical switches, ordered macroporous materials and so on. Nowadays colloidal particles which are used for colloidal crystals are mainly polystyrene, poly methyl methacrylate and silicon dioxide. Zinc oxide (ZnO) is a wide band gap semiconductor (3.37eV), and has high refractive index (2.1~2.2). Preparation of monodisperse ZnO colloidal particles and ZnO colloidal crystals, may help to expand the application of colloidal crystals.Microtube has a unique tubular structure and high surface area, and possesses excellent properties of the mechanism, dispersion and operability. It shows great potential value in electronics, biology, chemistry, materials science and micro-electromechanical systems. Recently, people focus on low dimensional ZnO materials of nano-structures such as nanowires, nanorods, nanotubes and nanobelts. The research about ZnO micron tubular structures is relatively rare.In this paper, monodisperse ZnO colloidal suspension is prepared using supernatant. ZnO colloidal crystals are self-assembled under gravity. ZnO microtube is prepared by hydrothermal method on the substrate of ZnO colloidal crystals. The main work and results are as follows:1. It is important to prepare monodisperse ZnO colloidal spheres by adding supernatant. The growth process of ZnO colloidal particles is researched and the growth mechanism of ZnO colloidal spheres is discussed.2. The volume of adding supernatant has an impact on ZnO colloidal spheres size. The diameter of the spheres is controlled by the volume of adding supernatant.3. The transmission spectra of ZnO colloidal crystal presents the characteristic properties of photonic bandgap, which shows that colloidal crystals are in the ordered arrangement. The position of transmission peak move to longer wavelength with the increase of ZnO colloidal spheres size. 4. ZnO microtube is prepared by hydrothermal method on the substrate of ZnO colloidal crystals. When the reaction temperature is 180℃, zinc acetate concentration is 0.50mol / L; the growth of ZnO microtube is controlled.