| 초록 |
The nanostructured silicas with spheres and tubules were synthesized through sol-gel reaction with ionic poly(styrene-block-4-vinylpyridine) (PS-b-P4VP) templates and silicate precursor (TEOS). Ionic block templates were prepared by protonation of poly(4-vinylpyridine) (P4VPs) with hydrochloric acid (HCl) and quaternization of P4VPs with methyl iodide (CH3I). The size of spheres and the morphological transition from spheres to tubules could be controlled by varying the degree of quaternization of PS-b-P4VP. The assemblies of micelle-silica hybrid compounds are induced as the number of ionic groups of P4VP and I- counterion decreases, which result in the formation of hierarchical structures such as spheres with a diameter larger than 50 nm and tubules. After moderated calcination process of as-synthesized, hollow structured silica with spherical and tubular shapes could be obtained which can be used for further applications such as drug delivery agents and supports for catalysts. |
