Aoshima Masayuki, Satoh Akira
Department of Machine Intelligence and System Engineering, Faculty of System Science and Technology, Akita Prefectural University, 84-4 Ebinokuchi, Tsuchiya-aza, Honjyo, Akita 015-0055, Japan.
J Colloid Interface Sci. 2005 Aug 15;288(2):475-88. doi: 10.1016/j.jcis.2005.02.093.
We have investigated aggregation phenomena in a polydisperse colloidal dispersion of ferromagnetic particles simulated by employing the cluster-moving Monte Carlo method in an applied magnetic field. The influence of both particle-particle and particle-field interactions on the aggregate structures is analyzed in terms of a pair correlation function. The results obtained in this study are summarized as follows: Under a strong magnetic field, chainlike clusters are formed along the magnetic field direction, and they become thickly clustered with an increase in the strength of the external magnetic field. Moreover, the thickly clustered chains are formed for a polydisperse system that has a large standard deviation of particle diameters. In contrast, for a very weak magnetic field, the strong interaction between the larger particles gives rise to the formation of various shapes in the chainlike clusters, including bending, looping, and branching. With an increase in the external magnetic field, these structures reorganize to form straight chainlike clusters. Furthermore, the thickness of the chainlike clusters for the polydisperse system is found to depend on the standard deviation of the particle-size distribution but is found to be independent of the magnetic field strength.
我们采用团簇移动蒙特卡罗方法，在施加磁场的情况下，对铁磁颗粒的多分散胶体分散体系中的聚集现象进行了研究。通过对关联函数分析了颗粒间相互作用和颗粒与场相互作用对聚集体结构的影响。本研究所得结果总结如下：在强磁场下，沿磁场方向形成链状团簇，且随着外磁场强度的增加，它们会密集聚集。此外，对于粒径标准差较大的多分散体系，会形成密集聚集的链。相反，在非常弱的磁场下，较大颗粒之间的强相互作用导致链状团簇中形成各种形状，包括弯曲、成环和分支。随着外磁场的增加，这些结构会重新组织形成直的链状团簇。此外，发现多分散体系中链状团簇的厚度取决于粒径分布的标准差，但与磁场强度无关。
