Video microscopy of dynamically aggregated paramagnetic particle chains in an applied rotating magnetic field
Video microscopy of dynamically aggregated paramagnetic particle chains in an applied rotating magnetic field
复制标题
DOI：
10.1021/la034195a
复制
发表时间：
2003-08
期刊：
影响因子：
3.9
通讯作者：
A. Vuppu;Antonio A. Garcia;M. Hayes
中科院分区：
文献类型：
--
作者：
A. Vuppu;Antonio A. Garcia;M. Hayes
由安装在电机上的永磁体产生的旋转单向磁场用于从悬浮液中动态聚集顺磁性颗粒以形成链。视频显微镜和图像处理被用来分析数据。在链和高达8 Hz频率的场之间观察到良好的同步性。链的增长是促进在非常低的旋转频率最初从静态条件下开始后，在此之后的平均链长减少响应于增加粘性阻力。随着频率从低值增加，平均链长最初快速减小，随后在较高频率下减小得更慢，从而导致两种状态：快速减小状态和缓慢减小状态。观察到典型的结构，如线性链和S形链，以及不寻常的U形结构。动态S形结构的形成可以根据链的柔性和角动量守恒原理来预测。F...
A rotating unidirectional magnetic field generated by a motor-mounted permanent magnet was used to dynamically aggregate paramagnetic particles from suspension to form chains. Video microscopy and image processing were used to analyze the data. Good synchronicity was observed between the chains and the field up to 8 Hz frequency. Chain growth is facilitated at very low rotational frequencies initially after starting from static conditions, after which the mean chain length decreases in response to increasing viscous drag forces. As the frequency is increased from low values, the mean chain length decreases initially rapidly and later more slowly at higher frequencies, thus resulting in two regimes: the fast and the slow decrease regimes. Typical structures such as linear chains and S-shaped chains are observed as well as unusual U-shaped structures. The formation of dynamic S-shaped structures can be predicted based on the flexibility of the chains and the principle of conservation of angular momentum. F...