蒙脱石分散体系中用Zeta电位修正静电作用能的计算

发布时间：2018-05-08 16:56

本文选题：Zeta电位 + 扩展的DLVO理论　；参考：《煤炭学报》2017年06期

【摘要】：针对扩展DLVO理论的静电作用能计算中表面电位难以测定,讨论以Zeta电位代替表面电位进行静电作用能计算的可行性。计算了蒙脱石表面电位,运用扩展的DLVO理论分别用Zeta电位和表面电位计算蒙脱石悬浮液的临界硬度,并通过蒙脱石悬浮液的临界硬度试验进行验证。试验结果表明:(1)悬浮液中蒙脱石颗粒表面与滑动面之间的水和电解质离子起到屏蔽表面电位的作用,表面电位计算的静电势能并不能反映颗粒间的静电作用;用Zeta电位代替表面电位计算颗粒间静电作用能,与实验结果更相符;(2)颗粒间滑动层开始接触时,水化作用能开始增大,电解质离子不仅减小了颗粒间的静电斥力,还减小了滑动层厚度,使水化作用距离缩短,颗粒更容易接近从而发生凝聚;(3)随电解质浓度的增加,蒙脱石颗粒Zeta电位和表面电位的绝对值均表现为减小的趋势,且表面电位的变动幅度要远高于Zeta电位的变动;双电层与滑动层厚度均呈指数减小。
[Abstract]:In view of the difficulty of measuring the surface potential in the calculation of the electrostatic action energy of the extended DLVO theory, the feasibility of calculating the electrostatic action energy by using the Zeta potential instead of the surface potential is discussed. The surface potential of montmorillonite was calculated. The critical hardness of montmorillonite suspension was calculated by Zeta potential and surface potential using extended DLVO theory, and verified by the critical hardness test of montmorillonite suspension. The experimental results show that the water and electrolyte ions between the surface of montmorillonite particles and the sliding surface in the suspension play the role of shielding surface potential, and the electrostatic potential energy calculated by the surface potential does not reflect the electrostatic action between the particles. The electrostatic interaction energy between particles is calculated by using Zeta potential instead of surface potential. When the sliding layer between particles is in contact with the experimental results, the hydration energy begins to increase, and electrolyte ions not only decrease the electrostatic repulsion force between particles. In addition, the thickness of the sliding layer is reduced, the hydration distance is shortened, the particles are more easily approached and condensed with the increase of electrolyte concentration, the absolute values of Zeta potential and surface potential of montmorillonite particles show a decreasing trend. The change of surface potential is much higher than that of Zeta potential, and the thickness of double layer and sliding layer decreases exponentially.
【作者单位】：中国矿业大学(北京)化学与环境工程学院;
【分类号】：TD94

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