خدابخش نیکنام

The mesoporous materials are porous particles where the pore size is between 2 to 50 nm. Mesoporous materials have attracted a great deal of interest due to their structural properties. For example, the monodisperse tunable natures of the pores make them ideal for separation and catalysis applications.MCM-41 is one of these materials that has an important properties such as high surface area and pore volume, uniform and controllable pores size and also high thermal stability. The synthesis, optimization and characterization of the novel mesoporous materials have been strongly promoted for its widely used as catalysts, adsorbents and etc. At this reaserach rapid and facile synthesis of mesoporous MCM-41 under basic and acidic conditions using cetyltrimethylammonium bromide (CTAB) as template and Tetraethyl orthosilicate (TEOS) as source silica is reported. In basic condition The synthesis variables such as CTAB / SiO2 and NH4OH / H2O molar ratios in the initial solution, reaction time , reaction temperature and hydrothermal operation, stirring rate and effect of addittives such as tert butyl alcohol (TBA) were studied. Also a few sample were synthesized in acidic condition. Finally two samples were synthesized under optimized conditions. Samples were characterized by XRD, TEM, SEM, nitrogen isothermal adsorption– desorption and FT-IR. It was found that reaction conditions affect the quantity and quality of final product. It was observed that NH4OH / H2O molar ratio and addition of TBA affect the efficiency of MCM-41severely. All of the variables are effective on morphology and particle size of MCM-41 but influence of reaction temperature were stronger than others as with decrease in temperature the particle size of product were growing strongly. Also under variation of parameters, textural properties of final product were varied but in optimized sample the average of pore size were increased up to 25 percent.