Dynamics of initial stage flocculation of polystyrene latex spheres with polyelectrolytes
Dynamics of initial stage flocculation of polystyrene latex spheres with polyelectrolytes
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DOI：
10.1016/0927-7757(96)03649-7
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发表时间：
1996-08-10
影响因子：
5.2
通讯作者：
Matsumoto, T
中科院分区：
文献类型：
--
作者：
Adachi, Y;Matsumoto, T
建立了一种端对端旋转装置，以获得适用于絮凝动力学研究的可再现混合。通过用库尔特计数器测定单分散聚苯乙烯胶乳粒子与简单电解质的凝聚速率，验证了该方法的有效性。该方法被应用于分析的初始行为的絮凝诱导的过量添加的絮凝剂与标称分子量为450万。与简单电解质的混凝相比，絮凝的初始阶段的速率显著提高，然后在一定的混合步骤后突然下降。增强的初始阶段的程度和此阶段的持续时间被发现依赖于浓度的三聚氰胺。由于附着的聚合物层，将增强归因于胶体颗粒的有效碰撞半径的增加，计算该层的厚度，delta（He）。分析表明，Δ（He）随着聚合物浓度增加而增加，直到500 nm的层厚度，这与溶液中聚合物的尺寸相关。然而，颗粒和聚电解质之间的碰撞过程的分析暗示，在初始阶段的聚合物吸附动力学的限制，直到接近饱和的运输。考虑到电泳迁移率的数据，我们的结论是，我们的结果是一致的动力学控制的聚合物吸附的图片提出的De Witt和货车de Ven [J.A.德威特和T.G.M.货车de Ven，Langmuir，8（1992）788]。
An end-over-end rotation apparatus was created in order to obtain reproducible mixing suitable for the study of the kinetics of flocculation. The validity was verified by measuring the rate of coagulation of monodispersed polystyrene latex particles with simple electrolytes by means of a Coulter Counter. The method was applied to the analysis of the initial behavior of flocculation induced by the addition of excess polyelectrolyte flocculant with a nominal molecular weight of 4.5 million. In contrast to coagulation with a simple electrolyte, the rate of flocculation in the initial stage was remarkably enhanced and then decreased abruptly after certain mixing steps. The degree of the initial stage of enhancement and the duration of this stage were found to be dependent on the concentration of the polyelectrolyte. Ascribing the enhancement to the increase in the effective collision radius of the colloidal particles due to the attached polymer layer, the thickness of this layer, delta(He), was calculated. Analyses showed that delta(He) increases as polymer concentration increases up to a layer thickness of 500 nm, which correlates with the size of the polymer in the solution. However, an analysis of the collision process between particles and polyelectrolytes implied that the kinetics of polymer adsorption in the initial stage are limited by transportation until near saturation. Taking into account the data on electrophoretic mobility, we concluded that our results are consistent with the picture of kinetically-controlled polymer adsorption proposed by De Witt and van de Ven [J.A. De Witt and T.G.M. van de Ven, Langmuir, 8 (1992) 788].