We study the dynamics of moving contact lines and film deposition on a chemically heterogeneous plate withdrawn from a liquid bath. The plate is patterned with vertical stripes characterized by alternating wettabilities. It is assumed that the interfacial slope with respect to the plate is small such that lubrication theory can be employed. The finite element method is used to solve the two-dimensional unsteady lubrication equation, which is coupled with the precursor film model and disjoining pressure to realize moving contact lines with finite contact angles. At low withdrawal velocity, a three-dimensional stable meniscus is formed. If the velocity exceeds a threshold, liquid films and droplets are produced on the more wettable stripes. When the width of the more wettable stripes is small, the contact line always loses its stability at the center of these stripes. For a sufficiently large width of the more wettable stripes, a trapezoidal film can be observed, in analogy to the wetting transition on a homogeneous plate of finite width; however, the onset of meniscus instability is found to occur at a location whose distance to the stripe boundary is independent of the stripe width, corresponding to a three-dimensional mechanism of wetting transition. Furthermore, the dynamic evolution of the liquid film is also analyzed.

中文翻译：

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化学条纹斜面上的动态润湿转变

我们研究了从液体浴中取出的化学异质板上移动接触线和薄膜沉积的动力学。印版上刻有垂直条纹，其特征是交替具有润湿性。假设相对于板的界面斜率小，使得可以采用润滑理论。利用有限元法求解二维非稳态润滑方程，并与前驱体膜模型和分离压力相结合，实现了有限接触角的移动接触线。在低抽出速度下，形成了三维稳定的弯月面。如果速度超过阈值，则会在更易润湿的条纹上产生液膜和液滴。当较易润湿的条纹的宽度较小时，接触线总是在这些条纹的中心失去稳定性。对于足够大的可润湿条纹的宽度，可以观察到梯形薄膜，类似于在有限宽度的均质板上的润湿转变；然而，发现弯液面不稳定发生在距条纹边界的距离与条纹宽度无关的位置，这对应于润湿转变的三维机制。此外，还分析了液膜的动态演变。发现弯液面不稳定发生在距条纹边界的距离与条纹宽度无关的位置，这对应于湿润转变的三维机制。此外，还分析了液膜的动态演变。发现弯液面不稳定发生在距条纹边界的距离与条纹宽度无关的位置，这对应于湿润转变的三维机制。此外，还分析了液膜的动态演变。