Synthesis And Application Of Fluorescent Mesoporous Silica Nanoparticles And Hollow Mesoporous Silica Nanoparticles

Mesoporous materials, especially, inorganic mesoporous materials have beenpaid much more attention during decades of years due to their unique properties, suchas large surface area, pore volume and ordered pore structure, etc. As a member of thefamily of mesoporous materials, mesoporous silica nanoparticles (MSNs) show theirextraordinary advantages compared with traditional mesoporous materials, such asbetter dispersibility in water, better biocompatibility in organism etc.Different from traditional fluorescent molecules, which always suffer fromaggregation-caused quenching (ACQ) effect, novel aggregation-induced emission(AIE) molecules nonemissive in solution are found to luminesce intensively uponmolecular aggregation. This unique feature makes it possible that the materials can beused in many fields where traditional dyes can not been applied, one of which issurper-amplified detection of explosives. However, the detection experiments aregenerally carried in mixed solvents (such as THF/water), considering the poordispersibility of AIE molecules in water, yet the stability of these experiments can notbe guaranteed, perhaps due to the irregular size of aggregates.In this thesis, the aggregation-induced emission (AIE) luminogen functionalizedmesoporous silica nanoparticles (MSNs) were prepared via post-grafting1,2-bis[4-(bromomethyl)phenyl]-1,2-diphenylethene (BTPE) on3-aminopropyltriethoxysilane modified MSN. The obtained materials combine theunique properties of the AIE luminogen and porous materials, and their emissionwavelength can be changed from467to527nm by loading different amount of AIEmolecules, showing an obvious red shift from blue light to yellow light. Importantly,such materials with well dispersibility in water can be used as an efficient fluorescentsensor for the detection of explosives, including picric acid (PA),4-nitrotoluene (4-NT), nitrobenzene (NB) in water, showing the sensitivity to the explosives in thesequence of NB>4-NT> PA. Furthermore, the obtained materials can be recycled bysimply washing with proper solvents. The high sensitivity, increased chemicalstability and recyclability of the AIE luminogen functionalized mesoporous silicananoparticles promise that they can be used as an excellent fluorescence probe forfuture practical applications in explosives detection.Hollow structured mesoporous silica nanoparticles (HMSNs) has beensynthesized by a facial and soft template method. The unique and uniform structure ofHMSNs makes it an efficient drug delivery carrier. Ibuprofen was used as a model toinvestigate the properties of loading and releasing drug molecules, showing theirpotential applications in these fields.