| 초록 |
Nanostructured organic-inorganic hybrid materials have been used as highly functional materials in wide varieties of applications such as optical and electromagnetic devices and metal catalysts. Organic-inorganic hybrids become even more interesting when the block polymer matrix is used as an organic template. Recently, mesoporous silica materials using block copolymer templates have attracted great interest. Structures and pore sizes of mesoporous silica materials have been controlled by block copolymer templates, typically PEO-PPO-PEO. It is well known that some mediates is necessary for association with silicate precursors for nonionic templates, however the direct association with silicate precursor is possible for ionic templates. Here, we synthesize new mesoporous materials using quaternized poly(styrene)-block-poly(4-vinylpyridine) (PS-b-P4VP) as a template. Since PS-b-P4VPs have advantages of both ionic surfactant and microphase-separated block copolymer, quaternized PS-b-P4VPs can directly associate with silicate precursor. PS-b-P4VPs were synthesized by anionic polymerization with various molecular weights and compositions. Quaternization of PS-b-P4VPs was performed with alkylhalide(CH3I, C2H5Br) and degree of quaternization depending on different quaternizing agents was calculated by combining FT-IR and nuclear magnetic resonance(NMR). Packing structure and pore size of mesoporous silicates using quaternized PS-b-P4VPs were characterized by small angle x-ray scattering(SAXS). transmission electron microsocope(TEM) and Brunauer Emmett Teller(BET). |
