Preparation of macroporous cordierite monoliths via the sol-gel process accompanied by phase separation

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• 作者：Xingzhong Guo ; Kazuki Nakanishi ; Kazuyoshi Kanamori ; Yang Zhu ; Hui Yang
• 关键词：Cordierite ; Monoliths ; Sol&ndash ; gel ; Phase separation
• 刊名：Journal of the European Ceramic Society
• 出版年：March, 2014
• 年：2014
• 卷：34
• 期：3
• 页码：817-823
• 全文大小：2725 K

文摘

Monolithic cordierite with a cocontinuous macroporous structure has been successfully prepared by the sol-gel process accompanied by phase separation in the presence of poly(acrylamide) (PAAm). Propylene oxide (PO) acts as an acid scavenger to mediate the gelation of MgO-Al₂O₃-SiO₂ ternary system, while PAAm works as a phase-separation inducer as well as a network former. The dried gel and that heat-treated at 800 掳C are amorphous, and the sapphirine begins to precipitate at 900 掳C, then transforming to orthorhombic 尾-cordierite at 1100 掳C. After heat-treated at and above 1200 掳C, the resultant 尾-cordierite further transforms to stable hexagonal 伪-cordierite. Heat-treatment changes the macroporous structure of cordierite monoliths such as macropore size and its distribution. The macroporous cordierite monolith after heat-treated at 1200 掳C is found to possess a total porosity of 54%, interconnected macropores and dense solid skeletons.