Preparation of mullite monoliths with well-defined macropores and mesostructured skeletons via the sol-gel process accompanied by phase separation
Preparation of mullite monoliths with well-defined macropores and mesostructured skeletons via the sol-gel process accompanied by phase separation
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DOI：
10.1016/j.jeurceramsoc.2013.02.018
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发表时间：
2013-09-01
影响因子：
5.7
通讯作者：
Yang, Hui
中科院分区：
文献类型：
--
作者：
Guo, Xingzhong;Li, Wenyan;Yang, Hui
具有明确大孔和介观结构骨架的莫来石整体材料是通过溶胶凝胶工艺制备的，并在聚环氧乙烷（PEO）存在下进行相分离。以氯化物盐作为附加前体的 Al2O3-SiO2 二元体系的凝胶化是由环氧丙烷 (PO) 作为酸清除剂介导的，而 PEO 作为相分离诱导剂。干燥后的凝胶和800℃热处理的凝胶为非晶态，900-1000℃结晶为γ-Al2O3或Si-Al尖晶石相纳米晶。在1100℃及以上热处理5h后，生成完全结晶的莫来石，得到大于15mm×15mm×10的大尺寸大孔整体材料。 毫米获得。 200-1400℃的热处理基本上不会破坏整体材料的大孔结构，但会减小大孔尺寸并显着改变相组成和微介孔结构。 (C) 2013 Elsevier Ltd. 保留所有权利。
Mullite monoliths with well-defined macropores and mesostructured skeletons have been prepared via the sol gel process accompanied by phase separation in the presence of poly(ethylene oxide) (PEO). Gelation of Al2O3-SiO2 binary system with chloride salts as an additional precursor has been mediated by propylene oxide (PO) as an acid scavenger, while PEO worked as a phase-separation inducer. The dried gel and that heat-treated at 800 degrees C are amorphous, and gamma-Al2O3 or Si-Al spinel phase nanocrystals are crystallind at 900-1000 degrees C. After heat-treated at and above 1100 degrees C for 5 h, the complete crystalline mullite is generated, and the macroporous monoliths in large dimensions of more than 15 mm x 15 mm x 10 mm are obtained. Heat-treatment at 200-1400 degrees C does not basically spoil the macroporous structure of monoliths, while decreases the macropore size and significantly alters the phase compositions and micro-mesoporous structure. (C) 2013 Elsevier Ltd. All rights reserved.