Nano α‐Al₂O₃ Powder Preparation by Calcining an Emulsion Precursor

Abstract

An experimental study has been conducted to evaluate the formation of nano a-Al 2 O 3 under various conditions, such as different calcining temperatures and emulsion ratios of aqueous aluminum nitrate solutions and oleic acid with a high-speed stirring mixer. Four batches of the precursor powders were calcined at three different temperatures of 10001, 10501, and 11001C for 2 h and a terminal product of nano a-Al 2 O 3 powders was obtained. The products have been identified by X-ray diffraction (XRD), specific surface area measurement scanning electron microscope, and transmission electron microscope (TEM). The XRD results show that the phase of powders is determined to be a-Al 2 O 3 , indicating that the overall process has been effective. The optimum calcination temperature of the precursor powder for crystallization of nano a-Al 2 O 3 was found to be 10001C for 2 h. The TEM image indicates that the particle grains have a subspherical shape with a mean size of 50-100 nm.

Synthesis and characterization of LaAlO3 nanopowders by emulsion combustion method

“…The first decomposition step assignable to removal of adsorbed and chemisorbed water is indicated by broad endothermic peak around 120 • C on the DTA curves. Exothermic peak between 200 and 600 • C in the DTA curves is due to the decomposition of oleic acid [20]. The thermal decomposition resulted in the formation of long chain ketones and the metal carbonates [21].…”

Nano α-Al2O3-t-ZrO2 composite powders by calcining an emulsion precursor at 1100°C

“…Although several methods have been used to synthesize this material, some improvement or an alternative suitable route is still required to obtain homogenous powders with smaller particle size at relatively low temperature for commercial production. Recently, Lee et al [9] prepared nano ␣-Al 2 O 3 with a favorable range of particle size near 30 nm by calcining an emulsion precursor derived from aluminium nitrate and oleic acid. Herein, we exploited the emulsion precursor method to prepare fine nanometer sized powder in the Al 2 O 3 -ZrO 2 system.…”

The Influence of Oleic Acid to Metal Nitrate Ratio on the Particle Size and Magnetic Properties of Lanthanum Ferrite Nanoparticles by Emulsion Method

“…The small reaction field and short reaction period lead to the formation of nanosize ceramic particles [16]. This technology, also known as calcination control of chemical additives (CCCA), has been used in previous studies for the preparation of LaAlO 3 [17,18], BaTiO 3 [19], Al 2 O 3 [20][21][22], ZrO 2 [23], -Al 2 O 3 -t-ZrO 2 [24], LiCoO 2 [25], Yttria stabilized zirconia [26], ZrO 2 -CeO 2 [27], ZnO [28], Fe 2 O 3 [28], CeO 2 [28], MgO [28], and ZnO-SiO 2 [29] fine powders. Hollow spheres of Al 2 O 3 TiO 2 ZrO 2 Y 2 O 3 , and solid particles of ZrO 2 -CeO 2 , ZnO, Fe 2 O 3 CeO 2 , MgO, and BaTiO 3 can be prepared by this process.…”