Université Montpellier 2, Laboratoire Charles Coulomb UMR 5221, F-34095 Montpellier, France and CNRS, Laboratoire Charles Coulomb UMR 5221, F-34095 Montpellier, France.
Phys Rev Lett. 2014 Mar 28;112(12):128303. doi: 10.1103/PhysRevLett.112.128303. Epub 2014 Mar 24.
We study the fingering instability of the interface between two miscible fluids, a colloidal suspension and its own solvent. The temporal evolution of the interface in a Hele-Shaw cell is found to be governed by the competition between the nonlinear viscosity of the suspension and an off-equilibrium, effective surface tension Γe. By studying suspensions in a wide range of volume fractions, ΦC, we show that Γe∼ΦC2, in agreement with Korteweg's theory for miscible fluids. The surface tension exhibits an anomalous increase with particle size, which we account for using entropy arguments.
我们研究了两种可混溶流体（胶体悬浮液及其自身溶剂）界面的指涉不稳定性。在亥姆霍兹细胞中，界面的时间演化由悬浮液的非线性粘度和非平衡有效表面张力 Γe 之间的竞争决定。通过研究各种体积分数 ΦC 的悬浮液，我们发现 Γe∼ΦC2，这与可混溶流体的科特威格理论一致。表面张力随颗粒尺寸表现出异常增加，我们用熵参数来解释这一现象。
