Mesoporous Silica Nanoparticles Synthesized By Binary Surfactant Templating System And Their Applications

Mesoporous silica nanoparticles (MSNs) have been widely investigated in the fields of catalysis, adsorption, separation, templating synthesis and biomedical sciences, due to their various advantages, such as tunable pore size and grometry, high specific surface area, pore volume and biocompatibility.In this thesis, the history, technology applications and research status were reviewed. On the basis of this, a binary surfactant system of F127 and CTAB was employed to successfully prepare a range of MSNs with controlled morphologies and uniform size. Furthermore, the application of MSNs as hard templates in preparing tin oxide hollow nanostructures and drug carriers for Ibuprofen loading and in vitro releasing were investigated. The primary significant results of this thesis are summarized as following:(1) The MSNs with different morphologies and similar mesopore geometry were prepared by binary surfactant templates in alkaline environment at room temperature. When CTAB was used as the sole surfactant, the morphology of silica nanoparticles were from spherical to nanorod and the length became longer. L/D ratio from 1:1 to 10:1 with CTAB concentration increasing from 0 to 36mM,. With the increase of CTAB/F127 concentrations ratio, MSNs morphologies evolved from rod-like to spherical-like particles, where a specific surface area of MSNs decreased firstly and then increased, and the pore size of all MSNs samples were approximately 2.5nm. It was found that CTAB mainly contributed to the pore structure of MSNs while F127 suppressed the particle growth.(2) The MSNs synthesized by binary surfactant have similar pore size and geometry and were investigated in drug delivery system. Ibuprofen (IBU) was loaded as drug model to uncover the drug loading and in-vitro releasing characterization. The results indicated that the quantity of the drug loaded mainly depended on the specific surface area, while the drug releasing kinetics was dominantly determined by the length and curvature of the mesopores. The controlled-release performance was improved when the length and curvature of mesopore increased. This study has therefore offered an opportunity to the further investigation of the more advanced MSNs drug carrier materials.(3) Hollow tin oxide nanostructures were obtained by using as-prepared MSNs as sacrificial templates through hydrothermal method. The shell thickness of hollow SnO2 can be controlled by adjusting the experiment factors, such as reactants concentration, urea concentration and tempature. The method present here could be applicable to preparing hollow structures of other oxide system.