1. ζ-potential variations of micro-nano sized hexagram-like α-Al2O3 particles.
- Author
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Hai, Chunxi, Zhang, Guotai, Liu, Jianghua, Zhou, Yuan, Dong, Shengde, Zeng, Jinbo, Li, Xiang, Sun, Yanxia, and Shen, Yue
- Subjects
SURFACE defects ,NANOPARTICLES ,SURFACE reactions ,INDUSTRIAL applications - Abstract
The relationship between ζ-potential and surface defects of micro-nano sized hexagram-like α-Al
2 O3 particles was investigated in this paper. The 2D α-Al2 O3 particles was prepared by the phase transformation of gibbsite precursor by the following steps during calcination in air: Al(OH)3 → AlOOH→a-Al2 O3 → θ-Al2 O3 → α-Al2 O3 . Resulting from the varied intensities of surface defects, as-prepared α-Al2 O3 samples have different Eg values around 4.5 eV, which is much narrower than that of bulk α-Al2 O3 . While benefiting from the interface reaction between surface > AlOH0 and water (>AlOH0 + OH− ⇋ > AlO− + H2 O), as-prepared α-Al2 O3 suspensions can reach their specific pHE values after stirring for 8 h at room temperature. And the measured IEP values of Al2 O3 -1250°C-2 h, Al2 O3 -1250°C-3 h, and Al2 O3 –1300 °C-3 h, which remain 2D morphology, are 7.96, 8.67, and 8.86, respectively. This study is significant and useful for making the industrial applications of α-Al2 O3 valid. [ABSTRACT FROM AUTHOR]- Published
- 2020
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