Study On Synthesis Chemestry And Its Drug Loading Application Of Hollow Mesopores Silica Spheres

Hollow mesoporous silica spheres has attracted increasing attention in recent years and has been applied in many important research fields, such as catalysis,drug/gene delivery, photonic crystals, and artificial cells,owing to its properties of uniform pore size, high surface area, large void space, abundant Si-OH active bonds,and good biocompatibility. However, the obtained hollow materials by many preparation methods are generally represent low stability, ill-defined in shape and polydispersed in size. Also, the hollow core size and mesoporous shell thickness cannot be easily and independently controlled by these techniques. However, these structural parameters and texture properties are important for their adsorption ability and stability.To overcome these problems,this thesis takes the synthesis and characterization of hollow mesoporous silica spheres(H-BMMs) as the main research contents, and finds out structure parameters and topographical variation rules as the research targets.This thesis systematically investigates various influence factors(such as RF content,ammonia content, cosolvent) on the structure performance of H-BMMs particles.Meanwhile, on the basis of our experience in the synthesis of SBA-15,H-SBA15 with ordered mesoporous was synthesized based on the literature method and the molar composition of the starting solution was the same as that of SBA-15. Furthermore,Ibuprofen(IBU) was employed as a model drug to investigate the drug-loading performance of H-BMMs and H-SBA15 series. The main results of the research contents are summarized as follows:1. In order to research the distribution of mesoporous structure in the shell wall,H-SBA15 with highly ordered parallel channel was synthesized based on the RF as hard template, three block copolymer(P123) as the soft template and the molar composition of the starting solution was the same as that of SBA-15. Furthermore, the properties of drug loading have been investigated in detail. The shell thickness of H-SBA15 series decreased with the increase of RF amount. Meanwhile, it shows that the IBU-loaded amount was increased with the increase of shell thickness of HSBA-15 series.2. Hollow mesoporous Silica Spheres(H-BMMs) were prepared under the condition of alkaline by using obtained RF latex as hard templates,cetyltrimethylammonium bromide(CTAB) as dual templates. Effects of the ammonia and RF contents on H-BMMs were discussed. Furthermore, the drug-loading performance of H-BMMs series were investigate. The shell thickness of H-BMMs canbe easily controlled by the changes of amount of RF content. The shell thickness of H-BMMs series decreased with the increase of RF amount. Meanwhile, With an increasing ammonia additive in the process, the hydrolysis rate of TEOS will be accelerated, leading the d value of(100) peak and primary pore size gradullly minished. It shows that the mesoporous structure of H-BMMs can be effectively“tailored” by the changes of amount of ammonia content. In addition, the loading of ibuprofen showed the H-BMMs had higher drug-loading potential(30%) much more than that of mesoporous molecular sieve. These results indicate that the IBU-loaded amount was decreased with the increase of shell thickness of H-BMMs series.3. Based on above research,the third charpter of this thesis studies the influence of N,N-Dimethylformamide(DMF) on the structure parameters and morphologies of H-BMMs. Simultaneously, the H-BMMs containing different amount of DMF are treated in hydrothermal conditions, and the corresponding structure parameters and topographical variation rule are summarized. The results show that the order degree of H-BMMs is reduced after addition of DMF. Furthermore,With an increasing DMF additive in the process, the hydrolysis rate of TEOS will be accelerated, leading the d value of(100) peak and primary pore size gradullly minished. Both rise the crystallization temperature and extend the crystallization time were unfavorable to keeping the ordered mesoporous structure of H-BMMs. When the temperature reaching at 120 ℃ or the time reaching at 48 h, the mesoporous stucture of H-BMMs will disappear be completely destroyed. However, when the addition of DMF, it will generate H-BMMs with a uniform shell thickness and good dispersion, etc.4. The resultant series of H-BMMs and H-SBA15 are well characterized by means of XRD, BET, SEM, TEM, FT-IR, HPLC and TG, and the corresponding synthesis mechanism is proposed.