Characterization and Pore Structure of Ordered Mesoporous SBA-15 Silica by Aging Condition

The study was done to change the morphology and pore size of SBA-15 silica, and the characteristics of SBA15 silica were investigated with TG-DSC, XRD, SEM, TEM and N-2 adsorption-desorption under changing aging conditions. SBA-15 silica having a 2D-hexagonal structure was synthesized and confirmed by SEM and TEM. The structure of mesoporus silica SBA-15 showed a pore having regularly formed hexagonal structure and a passage having a cylindrical shape. This result is in good agreement with the pore forming in XRD and cylindrical shape of the structure in N-2 adsorption-desorption isotherm. SBA-15 silica showed a large BET surface area of 603-698 m(2)/g, a pore volume of 0.673-0.926 cm(3)/g, a large pore diameter of 5.62-7.42 nm, and a thick pore wall of 3.31-4.37 nm. This result shows that as the aging temperature increases, the BET surface area, pore volume, and pore diameter increase but the pore wall thickness decreases. The BET surface areas in SM2 and SM-3 are as large as 698 m(2)/g. However, SM-2 has a large surface area and forms a thick pore wall, when the aging temperature is 100 degrees C and is synthesized into stable mesoporous SBA-15 silica.