Preparation Of Mesoporous Silica Nanoparticles With Novel Nanostructures And Their Applications In Drug Delivery And Catalysis

In recent years, the problem of human health and destruction of living environment caused by environmental pollution has became an important factor of sustainable development of human society. Toxic waste, waste residue and waste gas ruled out in the process of industrial production caused harmful substances increased year by year in the nature. These harmful substances have a seriously influence on human health. For example, the morbidity of cancer and other disease incidence caused by the heavy metal ions in water and PM2.5 is higher and higher. As a result,scientific community, the medical community and the government pay great attention to this phenomenon. The emergence of nanotechnology has brought a new dawn for this kind of problem solving. Because nanomaterials have large specific surface area,tunable pore size and pore volume, low toxicity and easy to surface functionalization characteristics widely used as nanoreactor or drug carrier used in environment, energy and biomedical sciences etc field. Thus, it is necessary to develop a highly efficient multifunctional nanocomposite. In this paper, we choose mesoporous silica nanoparticles as a research object. The synthesis mechanism and application in catalysis and biological medicine was studied. In addition, we preliminary explore the dual template preparation method of multilayer silica nanotubes. The main structure is as follows:In the first part: we studied the preparation of MMSNs and applications in biomedicine and catalysis field by using cetyltrimethylammonium bromide(CTAB)and dodecyl benzene sulfonicacid sodium(SBDS) as a mixed template agent.SEM/TEM results demonstrated that the obtained MMSNs possess sphere morphology(average diameter was about 180 nm), more than three layers of shell(average shell thickness is about 10 nm) and good dispersion. Based on the investigation to the variable and other experimental conditions, the possible synthesis mechanism of MMSNs was explored. In addition, we also investigated its application as a potential nanoreactor, catalyst, and drug carriers through loading different sizes ofgold nanoparticles, drug delivery of DOX and in vitro cytotoxicity test.In the second part: we studied the preparation of different channel structure mesoporous silica nanoparticles, and its application in catalytic and biological medicine. We through a simple and efficient method prepare four different channel structures mesoporous silica nanoparticles by using cetyltrimethylammonium bromide(CTAB) as template agent, ethyl acetate(EA) as template agent,tetraethylorthosilicate(TEOS) as silica source. According to the experimental results,the dosage of EA has a great influence on the morphology and channel structure. By TEM, SEM, BET, other characterization methods and the reaction conditions discussed, the synthesis process was studied out. In addition, we also use nitrophenol(4-NP), ibuprofen(IBU) and A549 cells to investigate its catalysis, drug loading and release properties, and biological compatibility. The experimental results showed that MSNs catalytic reduction 4-NP only need 4 min. The highest loading efficiency of IBU is 21.0 wt.%. In the pH = 7.4 buffer solution, the releasing rate of IBU is about94 %. When the concentration of samples is 100 g/mL, the survival rate of A549 cells is still as high as 85 %.In the third part: we preliminary explored the synthesis of multilayer shell silica nanotubes(MSNTs). We studied the influence of CTAB, SDBS, ethanol and ethyl acetate(EA) on the morphology, structure and the formation mechanism of MSNTs.