论文标题
在存在两个不混溶液体的情况下倾斜流量
Dip-coating flow in the presence of two immiscible liquids
论文作者
论文摘要
浸入涂层是一种通用技术，用于用薄液膜覆盖固体表面，其厚度是由Landau＆Levich和Derjaguin在1940年代开发的理论成功预测的。在这项工作中，我们将其理论扩展到浸入浴室中包含两个不混溶液体的情况下，一种液体比另一个轻质液体轻，从而夹带了两个薄膜在基板上。我们报告了涂层膜的厚度如何取决于毛细血管数，两种液体的性质和浴缸上流体层的相对厚度的比率。我们还表明，液体/液体和液体/气体界面彼此独立演变，好像只有一种液体被涂覆，除了一个很小的区域，在一个很小的区域中，它们的分离迅速降至其渐近值，而在两个接口峰处的剪切应力也是如此。有趣的是，我们发现最终涂层厚度取决于这些最大剪切应力的值。
Dip-coating is a common technique used to cover a solid surface with a thin liquid film, the thickness of which was successfully predicted by the theory developed by Landau & Levich and Derjaguin in the 1940's. In this work, we present an extension of their theory to the case where the dipping bath contains two immiscible liquids, one lighter than the other, resulting in the entrainment of two thin films on the substrate. We report how the thicknesses of the coated films depend on the capillary number, on the ratios of the properties of the two liquids and on the relative thickness of the upper fluid layer in the bath. We also show that the liquid/liquid and liquid/gas interfaces evolve independently from each other as if only one liquid was coated, except for a very small region where their separation falls quickly to its asymptotic value and the shear stresses at the two interfaces peak. Interestingly, we find that the final coated thicknesses are determined by the values of these maximum shear stresses.
