| 초록 |
Since the discovery of SBA-15, the control of external form and pore structure has been one of the important research subjects in mesoporous materials synthesis. Here we report the effects of the silica source and the agitation speed on the external form as well as the pore structure of SBA-15. For this purpose, we carried out the hydrothermal synthesis of SBA-15 with Si-(OC2H5)4 (TEOS) or Si-(OC4H9)4 (TBOS) as a silica source in a stirred tank reactor installed with an agitator. All the synthesized samples were characterized by XRD, BET, SEM and TEM. When TBOS was used as a silica source without agitation, both the particle size and the pore size were found larger than those of obtained with TEOS and the pore structure became disordered. With agitation of the reaction mixture, however, the hexagonal pore structure was maintained. When TEOS was used, the particle size tended to increase as the agitation speed increased up to 300 rpm, beyond which agitation had no influence. This indicates that the external form and the pore structure of SBA-15 can be changed by using different silica source and by adjusting the degree of agitation of the reaction mixture. |
