Comparison between the electrokinetic properties of kaolinite and montmorillonite suspensions at different volume fractions.
Comparison between the electrokinetic properties of kaolinite and montmorillonite suspensions at different volume fractions.
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DOI：
10.1016/j.jcis.2013.05.080
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发表时间：
2013-10
影响因子：
9.9
通讯作者：
Y. Tsujimoto;C. Chassagne;Y. Adachi
中科院分区：
文献类型：
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作者：
Y. Tsujimoto;C. Chassagne;Y. Adachi
我们研究了两种不同类型的粘土颗粒（高岭石和蒙脱石）的动电响应。高岭石悬浮液的介电常数在体积分数达到 20% 时与体积分数成线性比例，而蒙脱石的介电常数在体积分数低于 0.5% 时偏离线性关系。这表明蒙脱石颗粒在这些低体积分数下经历了颗粒-颗粒相互作用。然而，通过实验数据估计的两种粘土的复偶极系数在良好近似的实验误差内，与体积分数无关，并且与理论预测一致。低离子强度下粘土-水体系中的弛豫频率几乎由高岭石和蒙脱土的双层弛豫决定。对于体积分数大于 0.5% 的蒙脱石，我们发现电声方法测量的 zeta 电位开始强烈依赖于体积分数。预计对于这些高体积分数，偶极子系数也将变得与体积分数相关。
We have investigated the electrokinetic responses of two different kinds of clay particles, kaolinite and montmorillonite. The dielectric permittivity of kaolinite suspensions is linearly proportional to volume fraction up to volume fractions of 20%, whereas that of montmorillonite is deviating from a linear relationship, for volume fractions below 0.5%. This indicates that the montmorillonite particles experience a particle–particle interaction at these low volume fractions. The complex dipole coefficients of both clays estimated by experimental data are, however, within experimental error in good approximation independent on volume fraction and agree with the theoretical predictions. The relaxation frequency in clay–water system at low ionic strength is almost determined by the relaxation of the double layer for both kaolinite and montmorillonite. For volume fractions larger than 0.5% for montmorillonite, we find that the zeta potential measured by electroacoustic methods starts to depend strongly on volume fraction. It is expected that for these high volume fractions, the dipole coefficients will also become volume-fraction dependent.