The role of magnesium on the stability of crystalline sepiolite structure
The role of magnesium on the stability of crystalline sepiolite structure
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DOI：
10.1016/j.jeurceramsoc.2007.11.022
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发表时间：
2008-01-01
影响因子：
5.7
通讯作者：
Pecharroman, C.
中科院分区：
文献类型：
--
作者：
Esteban-Cubillo, A.;Pina-Zapardiel, R.;Pecharroman, C.
海泡石是一种水化镁硅酸盐特种粘土矿物，具有较大的比表面积（约320 m2/g）和较低的离子交换容量。此外，可以通过酸侵蚀在八面体层处浸出镁阳离子，从而将比表面积增加到结构崩溃的极限。在本研究中，我们已经发现，当浸出的Mg 2+的分数大于或等于0.33时，晶体框架崩溃。在坍塌之前，可以获得在八面体位置中具有不同取代金属阳离子的海泡石。以Ni-海泡石为例，在pH为0的条件下酸浸1 h，得到了最佳的组成，且结构没有破坏。(C)2008爱思唯尔有限公司保留所有权利。
Sepiolite is a hydrate magnesium silicate special clay mineral. Some of the specific properties of this silicate are its large specific surface (about 320 m(2)/g) together with a very reduced ion exchange capacity. Additionally, it is possible to leach the magnesium cations at the octahedral layer by acid attack, increasing the specific surface area up to the limit of the collapse of the structure. In the present investigation, we have found that the crystalline framework collapses when the fraction of leached Mg2+ is greater than or equal to 0.33. Before the collapse it is possible to obtain sepiolite with different substituted metallic cations into the octahedral sites. As an example, the optimal composition of Ni-sepiolite was obtained after the lixiviation by acid attack at pH 0 for 1 h without the collapse of structure. (C) 2008 Elsevier Ltd. All rights reserved.