Abstract: FSM-16, MCM-41 and SBA-15 types of hexagonal mesoporous silica with a highly ordered 2-dimensional structure were synthesized by using different silicon sources and surfactants. In the 2-dimensional silicate framework, pore size can be uniformly controlled by the combined use of the surfactants having different alkyl chain lengths and the swelling agents(triisopropyl benzene). The pore-diameter of FSM-16 and MCM-41 can be expanded to be 10 nm, SBA-15 to be 15 nm. The crystal regularity was decreased with the increase of the porediameter. In FSM-16 derived from kanemite (silicon source) and MCM-41 from water glass, their anionic characteristics on the pore-wall may be stronger than those of SBA-15 derived from oligomeric tetramethoxysilane(TMOS). We have successfully used FSM-16 and MCM-41 to immobilize the enzyme having cationic residues below isoelectric point. The level of adsorption of enzymes in FSM-16 and MCM-41 was relatively high, but was low in SBA-15 support. The mechanism of enzyme to be adsorbed in mesoporous silica was suggested to be the ionic interactions. In aqueous solutions, horseradish peroxidase(HTP) was immobilized in FSM-16 with 8. 9 nm mesopores and the highest loading amount (183 mg/mg FSM) was obtained, but for the FSM-16 of pore diameter 30 nm only an amount of 28 mg/mg FSM was obtained. The catalytic activity in the organic solvent was high when HRP was immobilized in FSM-16 and MCM-41, but it was low in case of SBA-15.

Key words: Mesoporous silica, Surfactant, Swelling agent, Enzyme, Activity