나노세공 Zirconia의 합성 및 특성평가

Abstract

Zirconia powders with nano size pores and high specific surface areas were synthesized via aqueous precipitation and hydrothermal synthetic method using ZrOCl28H2O and NH4OH under pH=11 and ambient condition. By this reaction, zirconia hydrate (ZrOx(OH)4-2x) was primarily synthesized and the obtained zirconia hydrate was heat treated hydrothermally using an autoclave at various temperatures under pH=11. X-ray diffraction, Scanning electron microscopy, Energy dispersive X-ray spectroscopy, FT-IR, Raman, Particle size analysis, DTA-TG, and BET techniques were used for the characterization of the powder. The synthesized zirconia showed an amorphous phase, however, the phase was transformed to the crystalline state during the hydrothermal process. The observed crystalline phase above 160oC was a mixed phase of monoclinic and tetragonal zirconia. By the BET analysis, it was found that the specific surface area was ranged in 126~276 ㎡/g and the zirconia had the cylindrical shaped pores with average diameter of 2~7 nm.