MOTIONS OF DROPLETS ON SOLID-SURFACES INDUCED BY CHEMICAL OR THERMAL-GRADIENTS
MOTIONS OF DROPLETS ON SOLID-SURFACES INDUCED BY CHEMICAL OR THERMAL-GRADIENTS
复制标题
DOI：
10.1021/la00086a025
复制
发表时间：
1989-03-01
期刊：
影响因子：
3.9
通讯作者：
BROCHARD, F
中科院分区：
文献类型：
--
作者：
BROCHARD, F
液滴在水平固体表面上的平衡形状由铺展系数S控制。对于部分润湿（S< 0），小于拉普拉斯长度k-1的液滴形成球形帽，而远大于k-1的液滴形成厚的“煎饼”。为了完全润湿，液体扩散成非常薄的煎饼。如果S是不均匀的，所有这些结构都开始运动。我们在小梯度极限（VS-*0）中讨论这个问题。对于两种情况：（I）VS是通过固体表面的化学处理获得的;在这里，我们预测液滴或煎饼在较低表面能的方向上移动。(II)VS是温度梯度VT的结果。马兰戈尼效应起着重要作用。如果液体的表面张力y是温度依赖性的，而所有其他的界面张力不是，我们预测运动向区域ofhigher表面能。
The equilibrium shape of a liquid droplet, lying on a horizontal solidsurface, is controlled by the spreading coefficient S. For partial wetting (S< 0), a drop smaller than the Laplace length k" 1 forms a spherical cap, while a drop much larger than~ forms a thick “pancake”. For complete wetting, the liquid spreads as a very thin pancake. If S is nonuniform, all these structures are set into motion. We discuss this in the limit of small gradients (VS-*0). for two cases:(I) VS is obtained via a chemical treatment of the solid surface; here we predict that the droplets, or pancakes, move in the direction of lower surface energies.(II) VS is the consequence of a temperature gradient VT. The Marangoni effect plays an important role. If the surface tension y of the liquid is temperature dependent, while all other interfacial tensions are not, we predict motions toward the regions ofhigher surface energies.