Chair of Magnetofluiddynamics, Measuring and Automation Technology, TU Dresden, 01069, Germany.
Soft Matter. 2018 Oct 31;14(42):8537-8544. doi: 10.1039/c8sm01456f.
We present results of a study of internal structures, which can appear in magnetic suspensions and gels filling a flat gap under the influence of a magnetic field applied perpendicular to the gap walls. The considered system consists of magnetizable microparticles with a mean diameter of ∼35 μm. Experimental observation demonstrates that the particles can form stable tube shaped structures elongated along the field direction. These structures have internal cavities. The theoretical analysis, performed in this study, shows that the tubes do not correspond to a thermodynamic equilibrium state of the system and rather present transitive non-ergodic structures. These structures are stacked in a state of local energetic minima because of the relatively large size of the particles and negligible Brownian effects. Our theoretical model is suggested to explain the physical reason of the appearance of tube-like structures.
我们呈现了一项研究的结果，该研究涉及在垂直于间隙壁施加磁场的情况下填充扁平间隙的磁悬浮液和凝胶中可能出现的内部结构。所考虑的系统由平均直径约为 35μm 的可磁化微粒子组成。实验观察表明，粒子可以形成沿场方向拉长的稳定管状结构。这些结构具有内部空腔。本研究进行的理论分析表明，这些管状结构与系统的热力学平衡状态不对应，而是呈现过渡的非遍历结构。由于粒子的尺寸相对较大且布朗运动的影响可以忽略不计，这些结构以局部能量最小的状态堆积。我们的理论模型被建议用来解释管状结构出现的物理原因。
