Synthesis of θ-Al<sub>2</sub>O<sub>3</sub> Whiskers with Twins
oleh: Nan Liao, Xiaojia Su, Haiwen Zhang, Qingguo Feng, Salvatore Grasso, Chunfeng Hu
| Format: | Article |
|---|---|
| Diterbitkan: | MDPI AG 2021-05-01 |
Deskripsi
In this work, θ-Al<sub>2</sub>O<sub>3</sub> whiskers with twins were successfully fabricated by a hydrothermal method followed by annealing at 1000 °C in argon atmosphere using Al<sub>2</sub>(SO<sub>4</sub>)<sub>3</sub>·18H<sub>2</sub>O, CO(NH<sub>2</sub>)<sub>2</sub> and PEG2000 as initial materials. It is confirmed that precursor of AlO(OH) whiskers is suitable to be used for preparing alumina whiskers when the molar ratio of Al<sup>3+</sup>:CO(NH<sub>2</sub>)<sub>2</sub> is selected to be 1:6. The mean length of obtained whiskers is 1.5 μm and the average width is 0.1 μm. Interestingly, it is found that the as-prepared θ-Al<sub>2</sub>O<sub>3</sub> whiskers consist of twins with (100) plane as the twin surface, which is ascribed to the phase transformation from tetragonal phase (δ-Al<sub>2</sub>O<sub>3</sub>) to monoclinic phase (θ-Al<sub>2</sub>O<sub>3</sub>) during the annealing. Additionally, the specific surface area of θ-Al<sub>2</sub>O<sub>3</sub> whiskers is measured to be 38.2 m<sup>2</sup>/g.