Synthesis And Characterization Of Mesoporous Silica Materials With Template

Up to now, mesoporous materials with ordered pore structures, large and regulablepore diameter, BET surface area and pore volume were rapidly developed because oftheir potential applications in many fields such as adsorption, catalysis, separation ofmacromolecules, optics, nano-assembly technologies, electronics, magnetisms andchemical sensors.1. In this thesis, the MCM-41 mesoporous silica was synthesized by using cationicsurfactant stearictrimethyl ammonium bromide (STAB) as template under strong acidconditions, and STAB was removed by calcination and hot ethanol-extraction. Thethree-dimension MCM-41 mesopores was characterized by FT-IR, SAXRD, nitrogenadsorption-desorption isotherm and HRTEM. The results showed that samples byextraction had bigger BET surface area and more ordered pore structure than those bycalcination, but pore structure could be more ordered under more rapid calefactiverate when calcining. SAXRD and TEM results indicated that all samples had ahexagon pore structures with narrow pore diameter distribution(2-3nm) and allnitrogen adsorption-desorption isotherm exhibited a Langmuirâ…£category which isrelated to mesoporous materials with large BET surface area (more than 1400m~2/g)and pore volume (1.04cm~3/g).2. In this part, a mesoporous titania materials was synthesized by using STAB astemplate, and FT-IR, SAXRD, HRTEM and nitrogen adsorption-desorption was takento the sample. The results showed that a worm-like pore structure with larger porediameter (8nm) was synthesized. Nitrogen adsorption-desorption isotherm showed aLangmuirâ…£category which is related to mesoporous materials, and the BET surfacearea and pore volume was 86m~2/g and 0.23cm~3/g respective.3. On the base of chapter 1 and 2, we synthesized ordered mesoporous silica bypolystyrene microemulsion as template under normal temperature and pressure, andtemplate was removed by calcination and hot ethanol-extraction, respectively.Similarly, the three-dimension MCM-41 mesopores was characterized by FT-IR, SAXRD, nitrogen adsorption-desorption isotherm and HRTEM. FT-IR results showedthat template could be thoroughly removed by two-time extraction. SAXRD andHRTEM results showed that the synthesized mesoporous materials had a hexagonpore structure same to MCM-41 with a pore diameter at 4-5nm. It was also analyzedthat all nitrogen adsorption-desorption isotherm exhibited a Langmuirâ…£categorywhich is related to mesoporous materials. And the samples had a uniform porediameter distribution, high surface area and pore volume (more than 1300m~2/g and1.27cm~3/g).