STRUCTURE EVOLUTION IN A PARAMAGNETIC LATEX SUSPENSION
STRUCTURE EVOLUTION IN A PARAMAGNETIC LATEX SUSPENSION
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DOI：
10.1016/0304-8853(93)91036-7
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发表时间：
1993-04-01
影响因子：
2.7
通讯作者：
GAST, AP
中科院分区：
文献类型：
--
作者：
FERMIGIER, M;GAST, AP
我们提出了超顺磁性乳胶粒子模型系统的聚集。我们测量的非平衡聚集过程的动力学。在低浓度下，当施加均匀且恒定的磁场时，颗粒经历吸引性偶极相互作用并通过平行于所施加的场的尖端到尖端聚集而形成线性链。我们发现，聚集是运输限制和平均集群大小随时间的平方根。在较高浓度下，横向相互作用改变聚集机制;观察到类似于“拉链”运动的链侧向聚结。这种现象导致链的增稠以产生颗粒的纤维，并最终导致链的交联。在旋转磁场中，在低浓度下，观察到线性聚集体。它们的大小随着旋转速率的增加而减小。在较高浓度下，形成圆形聚集体。
We present the aggregation of a model system of superparamagnetic latex particles. We measure the kinetics of the nonequilibrium aggregation process. At low concentration, when a uniform and constant magnetic field is applied, particles experience an attractive dipolar interaction and form linear chains by aggregating tip to tip parallel to the applied field. We find that the aggregation is transport limited and the mean cluster size increases with the square root of time. At higher concentrations, lateral interactions alter the aggregation mechanism; a sideways coalescence of the chains similar to a ''zippering'' motion is observed. This phenomenon results in a thickening of the chains to create fibers of particles and is eventually responsible for the crosslinking of chains. In a rotating magnetic field, at low concentrations, linear aggregates are observed. Their size decreases with an increasing rotation rate. At higher concentrations, circular aggregates are formed.