磁场下磁性液滴拉伸、移动和分裂现象及分析  

Phenomena and Analyses of Stretching,Moving and Splitting of the Magnetic Droplet Under the Magnetic Field

作　　者：陈芳[1] 楚明华 李晓琦[1] 李玉彬[1] 李学慧[1] 

机构地区：[1]大连大学物理科学与技术学院纳米磁性液体研发工作室,辽宁大连116622

出　　处：《微纳电子技术》2014年第9期571-575,共5页Micronanoelectronic Technology

基　　金：国家自然科学基金资助项目(51077006)

摘　　要：将油基磁性液体逐渐加入到甘油溶液中，在永磁铁作用下得到直径分别为2.0，2.5，3.0，3.5和4．0mm的磁性液滴。移除永磁铁后，观察分析不施加磁场或磁场换向频率为0～100Hz内磁性液滴的不稳定性现象，并用CCD摄像机记录实验过程中的瞬间变化。结果表明：磁性液体漂浮于甘油表层，永磁铁作用下汇聚成椭球型，移除永磁铁后较长时间（48h）内保持不变；磁场换向频率为0Hz时，磁性液滴沿磁场方向迅速移动；磁场换向频率大于0Hz小于等于100HZ时，磁性液滴随磁场换向频率的变化产生拉伸、移动和分裂现象。磁性液滴移动前其拉伸长度随时间逐渐变化；磁性液滴能够移动的最大换向频率随液滴初始直径的增大而增大；磁性液滴在拉伸移动过程中出现分裂现象。了解和掌握磁性液滴在换向磁场下的变化规律，将进一步拓展磁性液体在检测方面的应用。The oil-based magnetic fluid was gradually added to the glycerol, and magnetic droplets with diameters of 2.0, 2.5, 3.0, 3.5 and 4.0 mm were obtained under the effect of the permanent magnet. After the permanent magnet was removed, the instability phenomena of magnetic droplets without the magnet field or under the commutation frequency of the magnetic field at 0- 100 Hz were observed and analyzed, and the instantaneous changes during the experimental process were recorded by a CCD camera. The results show that the magnetic liquid floats on the surface of the glycerol and converges to the ellipsoid under the effect of the permanent magnet, maintaining for a longer time （48 h） after the permanent magnet is removed. When the commutation frequency of the magnetic field is 0 Hz, the magnetic droplet quickly moves along the direction of the magnetic field. The magnetic droplet stretches, moves and splits with the change of the commutation frequency of the magnetic field when the commutation frequency is greater than 0 Hz and less than or equal 100 Hz. Before the magnetic droplet moves, its stretched length graduallychanges with the time. The maximum commutation frequency at which magnetic droplets can move increases with the increase of the initial diameter of droplets, and the splitting phenomenon occurs for the magnetic droplet in the process of stretching and moving. Understanding the change rule of the magnetic droplet under the commutation magnetic will further expand the application of the magnetic liquid in the detection.

关 键 词：磁性液滴 磁场 拉伸 移动 分裂 换向频率 

分 类 号：TB383[一般工业技术—材料科学与工程] O482.54[理学—固体物理]