Disorder-induced hysteresis and nonlocality of contact line motion in chemically heterogeneous microchannels
Disorder-induced hysteresis and nonlocality of contact line motion in chemically heterogeneous microchannels
复制标题
化学异质微通道中无序引起的滞后和接触线运动的非定域性
DOI：
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
S. Kalliadasis
中科院分区：
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作者：
Christophe Wylock;M. Pradas;B. Haut;P. Colinet;S. Kalliadasis
我们研究了液体-空气半月板进入具有化学异质壁的微通道的运动。我们考虑了施加恒定流速，使得界面的平均速度保持不变的情况，并研究了无序性质对每个微通道表面表观接触角的影响。这里我们关注的是一个大的扩散系数区域，其中没有考虑任何可能的平流效应。为此，我们利用相场模型，通过扩散的界面通量实现接触线的运动，并考虑了壁面的润湿特性。结果表明，在足够低的速度范围内，接触角具有滞后行为，这种滞后行为随着无序强度的增强而增强。我们还发现，当不同的润湿性质施加在每个壁面上时，微通道每个表面的接触线动力学可能会变得很大程度上相互耦合，反映了界面的动力学是由非局域效应主导的。
We examine the motion of a liquid-airmeniscus advancing into a microchannel with chemically heterogeneous walls. We consider the case where a constant flow rate is imposed, so that the mean velocity of the interface is kept constant, and study the effects of the disorder properties on the apparent contact angle for each microchannel surface. We focus here on a large diffusivity regime, where any possible advection effect is not taken into account. To this end, we make use of a phase-field model that enables contact line motion by diffusive interfacial fluxes and takes into account the wetting properties of the walls. We show that in a regime of sufficiently low velocities, the contact angle suffers a hysteresis behavior which is enhanced by the disorder strength. We also show that the contact line dynamics at each surface of the microchannel may become largely coupled with each other when different wetting properties are applied at each wall, reflecting that the dynamics of the interface is dominated by nonlocal effects.