Surfactant-assisted Preparation, Characterization And Property Research Of Nanomaterials

In recent years, nanotechnology has become one of research focuses in materials science. Amongst, nanomaterials are the most important research object influencing the development of economy and society in the future, due to their unique properties including optical, electronic, magnetic properties and so on. This thesis mainly studied the influence of surfactants on the morphology and properties of products via using different synthetic routes such as solid-phase grinding, solvothermal synthesis and hydrothermal synthesis. Some main works are summarized as follows:1. A simple room-temperature solid-phase route was used for fast preparation of silver nanostructures employing AgNO₃ and VC (L-Ascorbic acid) as reactants in the presence of surfactants such as SDS and CTAB. Researches showed that aggregated Ag nanoparticles were prepared when the reactants were ground for 1h in the absence of any surfactant. Nanorods adsorbed Ag nanoparticles were produced when SDS existed and Ag nanowires were obtained when the system contained CTAB. The above experimental facts indicated that the presence of surfactants could affect the morphology and property of the final products prepared by the solid grinding route.2. Rod-like Cu₂O nanocrystals were successfully synthesized at 120℃for 30h via a simple solvothermal route in the presence of cetyltrimethylammonium bromide (CTAB), employing CuCl₂·2H₂O and KOH as the starting reactants, the glycol as the reaction medium. The experimental results showed that the reaction temperature or time could strongly influence the phase of the final product. CuO nanoparticles could be prepared at the lower temperature or the shorter time; Cu nanoparticles could be obtained at the higher temperature or the longer time.3. Flower-like ZnO nanocrystals were successfully synthesized via a simple hydrothermal synthesis route in the presence of sodium dodecyl sulfate (SDS), employing Zn(CH₃COO)₂ and KOH as the starting reactants. The phase and morphology of the product were characterized by means of XRD, TEM, SEM and SAED. The optical property of the product was studied. Some factors influencing the morphology of the final product including reaction time, temperature and amounts of the surfactant were discussed. Researches showed that the flower-like ZnO nanocrystals had a good photocatalytic activity for degradation of Safranine T under 254 nm UV light irradiation. The electrochemical research of the product showed that flower-like ZnO nanocrystals could promote electron transfers between catechol and the Au electrode. A possible formation mechanism was also suggested based on the results of the experiments.4. Manganese dioxide microspheres were prepared via a simple wet chemical route in the presence of sodium dodecyl sulfate (SDS) as the surfactant , employing MnSO₄·H₂O and (NH₄)₂S₂O₈ as the starting reactants. Such microspheres were characterized by scanning electron microscopy (SEM) and Powder X-ray diffraction (XRD).