Molten salt synthesis of mullite nanowhiskers using different silica sources
来源期刊：International Journal of Minerals Metallurgy and Materials2015年第8期
论文作者：Tao Yang Peng-long Qiu Mei Zhang Kuo-Chih Chou Xin-mei Hou Bai-jun Yan
文章页码：884 - 891
摘 要：Mullite nanowhiskers with Al-rich structure were prepared by molten salt synthesis at 1000°C for 3 h in air using silica, amorphous silica, and ultrafine silica as the silica sources. The phase and morphology of the synthesized products were investigated by X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, and transmission electron microscopy. A thermogravimetric and differential thermal analysis was carried out to determine the reaction mechanism. The results reveal that the silica sources play an important role in determining the morphology of the obtained mullite nanowhiskers. Clusters and disordered arrangements are obtained using common silica and amorphous silica, respectively, whereas the use of ultrafine silica leads to highly ordered mullite nanowhiskers that are 80-120 nm in diameter and 20-30 μm in length. Considering the growth mechanisms, mullite nanowhiskers in the forms of clusters and highly ordered arrangements can be attributed to heterogeneous nucleation, whereas disordered mullite nanowhiskers are obtained by homogenous nucleation.
Tao Yang1,2，Peng-long Qiu1，Mei Zhang1，Kuo-Chih Chou1,2，Xin-mei Hou1,2，Bai-jun Yan1
1. Department of Metallurgical Physical Chemistry, School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing2. State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing
摘 要：Mullite nanowhiskers with Al-rich structure were prepared by molten salt synthesis at 1000°C for 3 h in air using silica, amorphous silica, and ultrafine silica as the silica sources. The phase and morphology of the synthesized products were investigated by X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, and transmission electron microscopy. A thermogravimetric and differential thermal analysis was carried out to determine the reaction mechanism. The results reveal that the silica sources play an important role in determining the morphology of the obtained mullite nanowhiskers. Clusters and disordered arrangements are obtained using common silica and amorphous silica, respectively, whereas the use of ultrafine silica leads to highly ordered mullite nanowhiskers that are 80-120 nm in diameter and 20-30 μm in length. Considering the growth mechanisms, mullite nanowhiskers in the forms of clusters and highly ordered arrangements can be attributed to heterogeneous nucleation, whereas disordered mullite nanowhiskers are obtained by homogenous nucleation.
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