Micromixing with linked chains of paramagnetic particles
Micromixing with linked chains of paramagnetic particles
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DOI：
10.1021/ac0494580
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发表时间：
2004-11-01
影响因子：
7.4
通讯作者：
Gast, AP
中科院分区：
文献类型：
--
作者：
Biswal, SL;Gast, AP
顺磁性胶体粒子在外加磁场下聚集成线性链。这些粒子可以通过化学方式连接起来，形成可以被磁力驱动的链，以操纵微观流体流动。链的柔性可以通过改变连接分子的长度来调节。在本文中，我们描述了使用的链接顺磁链悬浮在旋转磁场中进行微尺度混合。通过观察酸和碱在微通道中的混合，研究了链旋转和柔性对分子扩散的影响。我们发现，随着链旋转频率的增加，有显着增加的有效混合之间的流体流，但是，存在一个最大的频率，并在此频率以上的链不再有效的混合。更灵活的链在更大的频率范围内混合时更有效。
Paramagnetic colloidal particles aggregate into linear chains under an applied external magnetic field. These particles can be chemically linked to create chains that can be magnetically actuated to manipulate microscopic fluid flow. The flexibility of the chain can be adjusted by varying the length of the linker molecule. In this paper, we describe the use of a suspension of linked paramagnetic chains in a rotating magnetic field to perform microscale mixing. The effect of chain rotation and flexibility on the diffusion of molecules is studied by observing the mixing of an acid and base in a microchannel. We show that, as the chain rotation frequency increases, there is marked increase in the effective mixing between fluid streams; however, a maximum frequency exists and above this frequency the chains are no longer effective in mixing. More flexible chains are more effective at mixing over a larger range of frequencies.