团聚-分散行为对悬浮液Zeta电位的影响

Effect of Aggregation and Dispersion on Zeta Potential of Suspensions

试验研究了NaCl和CaCl22种电解质加入量对不同粒径玻璃微珠(S1,S2,S3)和蒙脱石(M0)悬浮液Zeta电位的影响,以考察颗粒性质、颗粒粒径和电解质对Zeta电位和悬浮液稳定性(分散或团聚)的影响。试验结果表明,粒径较大的玻璃微珠S1和S2悬浮液Zeta电位随电解质的增加而逐渐增加,与文献中的描述基本一致;但粒径较小的玻璃微珠S3和蒙脱石M0悬浮液的Zeta电位随电解质的增加呈现出一些异常的变化,特别是在零电点附近发生了剧烈波动。分析S3和M0悬浮液Zeta电位出现异常变化的原因,可能是微细颗粒在零电点附近发生了较为明显的分散-团聚-再分散过程,团聚或分散过程又反过来影响到悬浮液的Zeta电位和粒度分布。

Effect of electrolyte, particle property and size distribution on particles aggregation of suspensions were investigated with two electrolytes of NaCl and CaCl2, three silica micro-ball samples of S1, S2, S3, and a montmorillonite sample of M0. The results of the experiments showed that the Zeta potential of S1 and S2 suspensions increased gradually with the amount of electrolyte added, which was almost the same as described in the literatures; but the Zeta potential of S3 and M0 suspensions showed some unusual variation, the Zeta potential curves did not increase with the amount of electrolyte added, but oscillated violently near the point of zero charge. This abnormal variation of Zeta potential for S3 and M0 suspensions might be induced from the processes of dispersion-aggregation-dispersion again around the point of zero charge, and the processes, in turn, affected the Zeta potential and size distribution of suspensions.