Magnetic-field-driven crack formation in an evaporated anisotropic colloidal assembly.
Magnetic-field-driven crack formation in an evaporated anisotropic colloidal assembly.
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DOI：
10.1103/physreve.94.012618
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发表时间：
2016-07
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影响因子：
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通讯作者：
Hisay Lama;Venkateshwar Rao Dugyala;M. Basavaraj;D. Satapathy
中科院分区：
文献类型：
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作者：
Hisay Lama;Venkateshwar Rao Dugyala;M. Basavaraj;D. Satapathy
我们报告的效果施加磁场的形状各向异性的椭球粒子组成的胶体悬浮液在玻璃基板上蒸发后形成的裂纹形态。蒸发实验是在固着液滴结构中进行的，这通常导致颗粒在液滴边界处积聚，通常称为“咖啡环效应”。“伴随裂纹的咖啡环状沉积物是在磁场存在和不存在的情况下形成的。然而，在这两种情况下形成的裂纹图案被发现显着不同。在磁场的存在下的裂纹的方向被发现是由粒子的取向，而不仅仅是由磁场方向。实验结果表明，在裂纹附近，颗粒是有序的，其长轴平行于裂纹方向。此外，我们观察到，裂纹间距一般随颗粒膜的高度而增加。
We report the effect of applied magnetic field on the morphology of cracks formed after evaporation of a colloidal suspension consisting of shape-anisotropic ellipsoidal particles on a glass substrate. The evaporation experiments are performed in sessile drop configuration, which usually leads to accumulation of particles at the drop boundaries, commonly known as the "coffee-ring effect." The coffee-ring-like deposits that accompany cracks are formed in the presence as well as in the absence of magnetic field. However, the crack patterns formed in both cases are found to differ markedly. The direction of cracks in the presence of the magnetic field is found to be governed by the orientation of particles and not solely by the magnetic field direction. Our experimental results show that at the vicinity of cracks the particles are ordered and oriented with their long-axis parallel to crack direction. In addition, we observe that the crack spacing in general increases with the height of the particulate film.