Capillary viscosimetry on ferrofluids
Capillary viscosimetry on ferrofluids
复制标题
铁磁流体的毛细管粘度测定法
DOI：
10.1088/0953-8984/20/20/204139
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
S. Odenbach
中科院分区：
文献类型：
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作者：
L. Pop;S. Odenbach
在剪切流动下对不同的铁磁流体进行的实验已经表明，施加到样品的磁场强度的增加产生流体的粘度的增加，即所谓的磁粘效应。它已被证明，效果的大小是强烈相关的铁磁流体的微观结构的修改，并可以通过改变粒子之间的偶极-偶极相互作用和流体内的大颗粒的浓度的影响。这一结果已被进一步用于合成新的铁磁流体，一方面，这是更兼容的技术应用，但另一方面，导致在磁场存在下的粘性行为的实验人员的困难。为了克服这个问题，一个专门设计的铁磁流体兼容的毛细管粘度计已经开发出来。在本文中，实验装置以及实验结果的调查，在稀释和浓缩的钴基铁磁流体的磁粘效应。
Experiments performed for different ferrofluids under shear flow have shown that an increase of the magnetic field strength applied to the sample yields an increase of the fluid’s viscosity, the so called magnetoviscous effect. It has been shown that the magnitude of the effect is strongly related to the modification of the microstructure of ferrofluids and can be influenced by varying both the dipole–dipole interaction between the particles and the concentration of large particles within the fluid. This result has been further used to synthesize new ferrofluids which, on one hand, are more compatible for technical applications but, on the other hand, led to difficulties for the experimenters in measuring the viscous behavior in the presence of a magnetic field. To overcome this problem, a specially designed ferrofluid-compatible capillary viscometer has been developed. Within this paper, the experimental setup as well as experimental results concerning the investigation of the magnetoviscous effect in both diluted and concentrated cobalt-based ferrofluids are presented.