The Synthesis Of Hollow Mesoporous Silica And Its Study Of Properties

In the past decades, more and more environment-friendly materials have attracted great attention for serious environmental pollution and increasing demand of people. Among them, silica is quite qualified for the role for its several advantages, such as extensive sources, low cost, and non-toxic. For the purpose of increasing specific surface area and pore volume, silica material could be made into mesoporous and hollow mesoporous structure. Additionally, silica surface could be easily modified to improve its biocompatibility. Therefore, mesoporous or hollow mesoporous silica materials set above all advantages and features at a suit and are widely applied to catalysis, biomedical engineering, and environment protection et al.In this thesis, various nanomaterials with different hollow mesoporous structure are fabrcated and characterized. A brief description of this paper is presented as follows:Chapter one:The synthesis, discussions of various influence factors, and applications of mesoporous silica nanoparticles (MSNs) and hollow mesoporous silica nanoparticles (HMSNs) are briefly reviewed.Chapter two:Single-shelled hollow mesoporous silica nanoparticles (SHMSNs) are fabricated by soft-templating method, sol-gel process, and selective etching strategies. TEOS and APTES are used as organic silica sources. Then, double-shelled hollow mesoporous silica nanoparticles (DHMSNs) are prepared using SHMSNs as initial template. In the procedure of preparation, various influence factors are discussed, such as catalyst, etching agent, reaction temperature, and etching time etc. After characterization, both SHMSNs and DHMSNs possess a well-defined hollow structure and have a high specific surface area (103.4 m2 g-1 for SHMSNs and 152.3 m2 g-1 for DHMSNs). In the experiments of drug load and release, SHMSNs and DHMSNs also have a good performance.Chapter three:The core-shell structure of mesoporous silica with a gold core (Au@mSiO2) is prepared according to reported method with some modification. Then, yolk-shell mesoporous silica containing a movable Au@mSiO2 core (Au@mSiO2@hollow mSiO2) is prepared by layer-by-layer and selective etching strategies. Likewise, the influence of the amount of gold precursor (HAuCl4) to gold nanocore coated in silica is also analysed. After characterization, both Au@mSiO2 and Au@mSiO2@hollow mSiO2 possess a well-dfined structure. Especially, Au@mSiO2@hollow mSiO2 have a good performance in thermal stability and possess a high specific surface area (270 m2 g-1).