Aoki K, Adachi Y
Graduate School of Life and Environmental Sciences, Tsukuba University, Tennodai 1-1-1, Tsukuba-shi, Ibaraki 305-8572, Japan.
J Colloid Interface Sci. 2006 Aug 1;300(1):69-77. doi: 10.1016/j.jcis.2006.03.027. Epub 2006 Mar 20.
The kinetics of the adsorption of a cationic polymer flocculant onto negatively charged polystyrene latex (PSL) particles were measured by means of electrophoresis as a function of the molecular weight of the polyelectrolyte and the ionic strength of the solution. In the experiment, the dispersion of bare PSL particles was mixed with a polyelectrolyte solution by means of end-over-end rotation in which the mixing intensity was evaluated in terms of the collision frequency between the colloidal particles. The rate of electrophoretic mobility of a PSL particle, which remained as a singlet, was measured against the mixing steps, which was equivalent to the time elapsed after the onset of flocculation. The shape of the kinetic curves is typical: a linear increase for a short period followed by a plateau, implying the saturation of the colloidal surface by the adsorbed polyelectrolyte. In the case of low ionic strength, the plateau value was dependent on the molecular weight of the polyelectrolyte. That is, a lower plateau value was detected when the molecular weight of the polyelectrolyte was smaller and its concentration was lower. However, the amount of adsorption was kinetically controlled only for the case of higher molecular weight. In the case of high ionic strength, the plateau value of electrophoresis was constant, regardless of the polyelectrolyte concentration and molecular weight. These data will ultimately be useful in further analysis of the flocculation behavior of colloidal particles with a polyelectrolyte.
通过电泳测量阳离子聚合物絮凝剂在带负电荷的聚苯乙烯胶乳（PSL）颗粒上的吸附动力学，该动力学是聚电解质分子量和溶液离子强度的函数。在实验中，通过端对端旋转将裸露的PSL颗粒分散体与聚电解质溶液混合，其中混合强度根据胶体颗粒之间的碰撞频率进行评估。针对混合步骤测量作为单颗粒保留的PSL颗粒的电泳迁移率，混合步骤相当于絮凝开始后经过的时间。动力学曲线的形状很典型：短时间内呈线性增加，随后达到平稳期，这意味着吸附的聚电解质使胶体表面达到饱和。在低离子强度的情况下，平稳期值取决于聚电解质的分子量。也就是说，当聚电解质的分子量较小且其浓度较低时，检测到的平稳期值较低。然而，仅在高分子量的情况下吸附量受动力学控制。在高离子强度的情况下，电泳的平稳期值是恒定的，与聚电解质浓度和分子量无关。这些数据最终将有助于进一步分析胶体颗粒与聚电解质的絮凝行为。
