Max-Planck-Institut für Kolloid- und Grenzflächenforschung, Potsdam-Golm, Germany.
Phys Rev Lett. 2012 Aug 10;109(6):066103. doi: 10.1103/PhysRevLett.109.066103.
Capillarity always favors drop fusion. Nevertheless, sessile drops from different but completely miscible liquids often do not fuse instantaneously upon contact. Rather, intermediate noncoalescence is observed. Two separate drop bodies, connected by a thin liquid neck, move over the substrate. Supported by new experimental data, a thin film hydrodynamic analysis of this state is presented. Presumably advective and diffusive volume fluxes in the neck region establish a localized and temporarily stable surface tension gradient. This induces a local surface (Marangoni) flow that stabilizes a traveling wave, i.e., the observed moving twin drop configuration. The theoretical predictions are in excellent agreement with the experimental findings.
毛细现象总是有利于液滴融合。然而，来自不同但完全可混溶的液体的固着液滴在接触时通常不会立即融合。相反，会观察到中间不聚结的情况。两个单独的液滴体通过一个细液颈相连，在基底上移动。本研究基于新的实验数据，对该状态进行了薄膜流体动力学分析。颈区中的对流和扩散体积通量可能会在局部建立一个暂时稳定的表面张力梯度。这会引起局部表面（马兰戈尼）流，从而稳定行波，即观察到的移动双液滴构型。理论预测与实验结果非常吻合。
