Temperature effect on the acid-base behaviour of Na-montmorillonite
Temperature effect on the acid-base behaviour of Na-montmorillonite
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DOI：
10.1016/j.jcis.2008.08.050
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发表时间：
2008-11-15
影响因子：
9.9
通讯作者：
Gaboriaud, Fabien
中科院分区：
文献类型：
--
作者：
Duc, Myriam;Carteret, Cedric;Gaboriaud, Fabien
本文报道了用连续电位法和间歇电位法，结合溶解和再吸附物种的分析，研究了钠基蒙脱石悬浮液在25-80℃温度范围内的酸碱性质。批次滴定曲线表明，在酸性和碱性pH条件下，随着温度的升高，钠基蒙脱石和富硅第二相的溶解过程逐渐占优势。连续滴定曲线受这些副反应的影响较小。在没有公共交点的情况下，对曲线的热力学分析是基于PZNPC随离子强度的移动。与相同条件下水的解离产物相比，温度对这一变化没有显著影响。因此，我们得出结论，粘土小片边缘可解离位置的质子化-去质子化与温度没有明显的依赖关系。(C)2008 Elsevier Inc.保留所有权利。
We report a study of the acid-base properties of Na-montmorillonite suspensions at temperatures from 25 degrees C to 80 degrees C, by continuous and batch potentiometric methods, combined with analysis of the dissolved and readsorbed species. The batch titration curves reveal that the dissolution processes of Na-montmorillonite and silica-rich secondary phases are increasingly predominant, respectively at acid and basic pH, and according to the temperature. The continuous titration curves are less affected by these side reactions. In the absence of a common intersection point, the thermodynamic analysis of the curves was based on the shift of the PZNPC with the ionic strength. This shift was not significantly altered by the temperature, by comparison with the dissociation product of water in the same conditions. Therefore we concluded that protonation-deprotonation of the dissociable sites at the edges of the clay platelets is not significantly temperature dependent. (C) 2008 Elsevier Inc. All rights reserved.