| 고분자 P123와 란탄이 도핑된 알루미나의 특성 연구 |
| 정미원, 이미회 |
| 성신여자대학교 화학과 |
| Characterization of Alumina Doped with Lanthanum and Pluronic P123 via Sol-Gel Process |
| Mie-Won Jung, Mi-Hoe Lee |
| Department of Chemistry, Sungshin Women's University |
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| ABSTRACT |
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To direct the evolution of nanostructure and immobilize ${gamma}-Al_2O_3$ catalyst, nanocrystalline La-doped-$Al_2O_3$ powder were prepared by the sol-gel process with addition of an amphiphilic block copolymer template (pluronic P123: $(poly(ethyleneoxide)_{20}-poly(propyleneoxide)_{70}-poly(ethyleneoxide)_{20})$. The dried gel is amorphous, whereas heating at temperature above $700^{circ}C$ leads to the formation of nanocrystalline ${gamma}$ and ${delta}-Al_2O_3$ and these two phases is kept until $1100^{circ}C$. ${alpha}-A1_2O_3 $starts to form at $1200^{circ}C$ with $LaAl_{11}O_{18}$. The surface morphology and crystal structure has been observed by field emission scanning electron microscope (FE-SEM) and X-ray diffraction (XRD). Solid state $^{27}Al$ MAS NMR indicates two types of local environment, i.e. octahedral and tetrahedral sites. The surface area and pore size was compared among these powders using the BET nitrogen adsorption measurements. |
| Key words:
La-doped-$Al_2O_3$, Amphiphilic block copolymer$^{27}Al$ NMR |
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