Preparation of Fine Mullite Powders with High Surface Area by Agglomeration Control of Alkoxide-derived Precursor Sol
Preparation of Fine Mullite Powders with High Surface Area by Agglomeration Control of Alkoxide-derived Precursor Sol
复制标题
通过醇盐前驱体溶胶的团聚控制制备高比表面积细莫来石粉
DOI：
10.4164/sptj.34.170
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发表时间：
1997
影响因子：
--
通讯作者：
T. Ota
中科院分区：
文献类型：
--
作者：
Hisao Suzuki;M. Shimizu;H. Kamiya;Minoru Takahashi;T. Ota
通过分子设计的铝、硅络合物醇盐的水解制备了超细莫来石前驱体粉末。由溶胶-凝胶途径得到的莫来石粉末的表面积根据老化和/或干燥条件而变化。这是由于它们的初级颗粒的团聚状态不同，这些初级颗粒是通过前体溶液的水解而沉淀的。在低介电常数溶剂的初级颗粒上形成薄的双电层，然后初级颗粒团聚成粗的二次团聚体，即使在高温煅烧后也能得到具有高表面积的莫来石粉末。初级颗粒上的厚双电层导致均匀堆积，在干燥过程中形成相对致密的二次团聚体。当老化过程中使用高介电常数的溶剂时，这会导致表面积降低。这种团聚行为通过莫来石粉末的孔径分布和 SEM 观察得到证实。
Ultra-fine mullite precursor powders were prepared by the hydrolysis of molecular-designed Al, Si-complex alkoxide. The surface areas of the resulting mullite powders derived from sol-gel route varied depending upon the aging and/or drying condition. This was due to the different agglomeration states of their primary particles, which precipitated by the hydrolysis of the precursor solutions. A thin electrical double layer was formed on the primary particles of the solvents with low dielectric constants, and then primary particles agglomerated into coarse secondary agglomerates, leading to mullite powders with high surface areas even after high-temperature calcination. A thick electrical double layer on the primary particles resulted in the uniform packing, which formed relatively dense secondary agglomerates during drying. This resulted in the lower surface areas when solvents with high dielectric constants were used during aging. This agglomeration behavior was confirmed by pore-size distributions and the observation of SEM of the mullite powders.