Mesoscopic structures of vermiculite and weathered biotite clays in suspension with and without cesium ions.
Mesoscopic structures of vermiculite and weathered biotite clays in suspension with and without cesium ions.
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DOI：
10.1021/la503992p
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发表时间：
2014-12
期刊：
影响因子：
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通讯作者：
R. Motokawa;H. Endo;S. Yokoyama;H. Ogawa;Tohru Kobayashi;Shin'ichi Suzuki;T. Yaita
中科院分区：
文献类型：
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作者：
R. Motokawa;H. Endo;S. Yokoyama;H. Ogawa;Tohru Kobayashi;Shin'ichi Suzuki;T. Yaita
利用小角X射线散射（SAXS）研究了铯（Cs）吸附对悬浮液中粘土矿物蛭石和风化黑云母（WB）介观结构的影响。粘土矿物形成多层结构，Cs阳离子（Cs（+））强烈吸附在土壤粘土，特别是蛭石和WB的层间空间。用小角X射线散射（SAXS）方法研究了Cs（+）在粘土层间的吸附与粘土层结构变化之间的关系。阐明了Cs（+）存在和不存在时，粘土片之间的距离变化和粘土片的空间排列。定量分析表明，Cs（+）的加入使蛭石的堆积层数减少，而WB的增加。悬浮液中蛭石层间平均距离大于WB层间平均距离，反映了Cs（+）插层条件的不同。这些发现提供了基本的见解，是重要的预测环境命运的放射性铯污染地区和开发方法提取Cs从土壤中。
The effect of cesium (Cs) adsorption on the mesoscopic structure of the clay minerals vermiculite and weathered biotite (WB) in suspensions was elucidated by small-angle X-ray scattering (SAXS). The clay minerals form multilayered structures, and the Cs cations (Cs(+)) are strongly adsorbed in the interlayer space of the soil clays, in particular vermiculite and WB. SAXS was used to monitor the relationship between Cs(+) adsorption at the clay interlayers and the structural changes at length scales from 1 to 1000 Å. The variation in the distance between the neighboring clay sheets and the spatial arrangement of the clay sheets with and without Cs(+) were clarified. Our quantitative analyses revealed that the number of stacked layers of pure vermiculite was decreased by Cs(+) addition, whereas that of WB increased. Moreover, the average distance between the neighboring layers of vermiculite in suspension was larger than that of WB, which reflects the different conditions of Cs(+) intercalation. These findings provide fundamental insights that are important for predicting the environmental fate of radioactive Cs in contaminated regions and for developing methods for extracting Cs from soil.