Berim Gersh O, Ruckenstein Eli
Department of Chemical and Biological Engineering, State University of New York at Buffalo, Buffalo, New York 14260, USA.
J Chem Phys. 2008 Sep 21;129(11):114709. doi: 10.1063/1.2978238.
A two-dimensional nanodrop on a vertical rough solid surface is examined using a nonlocal density functional theory in the presence of gravity. The roughness is modeled either as a chemical inhomogeneity of the solid or as a result of the decoration with pillars of a smooth homogeneous surface. From the obtained fluid density distribution, the sticking force, which opposes the drop motion along an inclined surface, and the contact angles on the lower and upper leading edges of the drop are calculated. On the basis of these results, it is shown that the macroscopically derived equation for a drop in equilibrium on an inclined surface is also applicable to nanodrops. The liquid-vapor surface tension involved in this equation was calculated for various specific cases, and the values obtained are of the same order of magnitude as those obtained in macroscopic experiments.
利用非局部密度泛函理论，在考虑重力的情况下，对垂直粗糙固体表面上的二维纳米液滴进行了研究。粗糙度被建模为固体的化学不均匀性，或者是光滑均匀表面用柱状物修饰的结果。根据得到的流体密度分布，计算了阻止液滴沿倾斜表面运动的附着力以及液滴上下前缘的接触角。基于这些结果，表明宏观推导的倾斜表面上平衡液滴的方程也适用于纳米液滴。针对各种具体情况计算了该方程中涉及的液 - 气表面张力，得到的值与宏观实验中获得的值具有相同的数量级。
