Controllable Synthesis And Catalytic Properties Of Functional Mesoporous Silica Nanoparticles

Mesoporous silica materials are widely applied in catalysis and biomedical fields. Following the development of MCM and SBA series mesoporous materials, mesoporous silica nanoparticles (MSNs) attract much research interests because of their controllable particle sizes and simple synthetic methods. Among them, dendritic mesoporous silica nanoparticles (DMSNs), which have open dendrimer-like channels and excellent physiochemical properties, are considered as promising materials in biomedical and catalysis. Thus, this dissertation focus on the new synthetic method and applications of functional dendritic mesoporous silica nanoparticles.In the first part of the dissertation, dendritic mesoporous silica nanoparticles are synthesized with mixed anionic and cationic surfactants. Dendritic mesoporous silica nanoparticles and nanoparticles with other particular morphologies are obtained by changing the kinds and alkyl length of anionic/cationic surfactants. Meanwhile, Ti-containing materials (Ti-DMSNs) are achieved during the synthetic process by adding Ti source in situ. Ti-DMSNs exhibit excellent catalytic performance in the epoxidation of cyclohexene which is comparable with traditional Ti-MCM-41.In the second part of dissertation, various alkalis are firstly used in the synthesis of dendritic mesoporous silica nanoparticles and their effects are also investigated. Then, Au source is introduced into the synthetic process with different kinds of alkali, and various Au-SiO2 composites, including monodisperse and core-shell nanostructures are obtained. Multiple functions of triethanolamine (TEAH3) as base catalyst, reducing agent and growth inhibitor are confirmed in the synthesis of Au@DMSNs. At last, the catalytic behaviors of Au catalysts are tested in the reduction of p-nitrophenol.