Self-Assembling Process of Colloidal Particles into Two-Dimensional Arrays Induced by Capillary Immersion Force: A Simulation Study With Discrete Element Method
Self-Assembling Process of Colloidal Particles into Two-Dimensional Arrays Induced by Capillary Immersion Force: A Simulation Study With Discrete Element Method
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DOI：
10.1023/a:1024489832472
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发表时间：
2003-04
影响因子：
2.5
通讯作者：
H. Nishikawa;S. Maenosono;Y. Yamaguchi;T. Okubo
中科院分区：
文献类型：
--
作者：
H. Nishikawa;S. Maenosono;Y. Yamaguchi;T. Okubo
本文对毛细管浸没力作用下胶体粒子自组装成二维阵列的过程进行了模拟研究。采用离散元法模拟了被困在液体薄膜中的胶体颗粒的动力学过程。对模型进行了改进，修正了毛细浸没力的筛选作用，引入了周期边界条件。模拟所提供的快照与原子力显微镜所拍摄的实验图像吻合较好。用对相关函数和配位数对自组装过程进行了量化。在较低的覆盖率下，胶体颗粒在早期阶段迅速形成由几个颗粒组成的小簇。随后主要生成带有分支的链状结构。另一方面，在较高的覆盖范围内，逐渐形成大的六边形密排结构域。HCP结构域的生长速度远低于小簇和链状结构的生长速度。
This paper presents a simulation study for self-assembling process of colloidal particles into two-dimensional arrays due to capillary immersion force. Discrete element method is used to simulate the dynamics of colloidal particles trapped in a thin liquid film. The previous model is improved in the following two points: a modification of the screening effect of capillary immersion force and introduction of periodic boundary condition. Snapshots provided by the simulations agree well with experimental images taken by atomic force microscopy. The self-assembling process is quantified with pair correlation function and coordination number. At lower coverage, colloidal particles rapidly form small clusters that consist of several particles in the early stage. Subsequently, chain-like structures with some branches are mainly generated. On the other hand, at higher coverage, large domains of hexagonal close-packed (HCP) structures are gradually generated. The rate of the growth of HCP domains is much slower than that of the generation of the small clusters and the chain-like structures.