Magnetic assembly of colloidal superstructures with multipole symmetry
Magnetic assembly of colloidal superstructures with multipole symmetry
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DOI：
10.1038/nature07766
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发表时间：
2009-02-19
期刊：
影响因子：
64.8
通讯作者：
Yellen, Benjamin B.
中科院分区：
文献类型：
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作者：
Erb, Randall M.;Son, Hui S.;Yellen, Benjamin B.
从简单的胶体构建块组装复杂结构对于构建具有独特光学性质的材料（例如光子晶体（1）和DNA生物传感器（2））具有实际意义，并且对于提高我们对发生在分子到宏观长度尺度上的自组装过程的理解具有根本重要性（3-5）。在这里，我们展示了一种自组装原理，该原理能够将一组不同的胶体颗粒组织成高度可重复的、旋转对称的排列。这些结构是利用磁化铁磁流体中有效的反磁性和顺磁性粒子之间的静磁相互作用组装的。由此产生的多极几何形状类似于静电荷配置，例如轴向四极（“土星环”），轴向八极（“花”），线性四极（极）和混合多极排列（“双音”），这些只是可以使用这种技术构建的结构类型的几个例子。
The assembly of complex structures out of simple colloidal building blocks is of practical interest for building materials with unique optical properties ( for example photonic crystals(1) and DNA biosensors(2)) and is of fundamental importance in improving our understanding of self- assembly processes occurring on molecular to macroscopic length scales(3-5). Here we demonstrate a self-assembly principle that is capable of organizing a diverse set of colloidal particles into highly reproducible, rotationally symmetric arrangements. The structures are assembled using the magneto-static interaction between effectively diamagnetic and paramagnetic particles within a magnetized ferrofluid. The resulting multipolar geometries resemble electrostatic charge configurations such as axial quadrupoles ('Saturn rings'), axial octupoles ('flowers'), linear quadrupoles (poles) and mixed multipole arrangements ('two tone'), which represent just a few examples of the type of structure that can be built using this technique.