| Micro-or nano-scaled mesoporous silica nanoparticles(SiO2)possess some unique advantages,such as high surface area,large pore volume,controllable pore size and morphology,which makes it a hot research topic and widely used in applications like catalyst and drug delevery.In this study,chiral mesoporous silica nanoparticles with various aspect ratio were prepared.Then rod-like hollow mesoporous silica nanoparticles were synthesized creatively using mesoporous silica nanoparticles as templates.This dissertation includes two main parts: In the first part,Chiral MCM-41 mesoporous silica nanorods with tunable aspect ratio were produced by using achiral template without auxiliary additives.The influence of different synthesis conditions on the final product was studied,which determined the factors that affect the final product morphology and pointed out the direction for the synthesis of products to meet the needs of applications.Through the use of online IR,TEM and other detection means,the formation process of chiral mesoporous silica were observed,based on which the formation mechanism of chiral mesoporous silica was put forward.In the second part,a shape-controlled synthesis of hollow silica nanocapsules(HSNCs)has been achieved by an improved self-templating method.First,mesoporous silica templates with different shapes were synthesized by using surfactant,then surfactant free formation of solid silica shells was conducted outside of the mesoporous silica with PVP coating next,At last,selective etching was carried out and HSNCs were got.By adjusting the process parameters as well as the factors such as the ratio of raw materials,different shape(short rods,long stick,broad beans,etc.)products could be prepared.The product has the advantages of low density,large storage space,and easy modification,therefore has potential value in application areas such as catalysis,controlled-release,bioengineering.All the contents above have never been reported at present. |
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