Mejía Andrés, Vega Lourdes F
Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Consejo Superior de Investigaciones Científicas, Campus de la Universitat Autónoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
J Chem Phys. 2006 Jun 28;124(24):244505. doi: 10.1063/1.2206772.
Wetting behavior along a three-phase equilibrium has been obtained by density gradient theory (DGT) and molecular dynamics simulations for a type-II equal size Lennard-Jones mixture. In order to perform a consistent comparison between both methodologies, the molecular parameters of this type of mixture were defined from the global phase diagram of equal size Lennard-Jones mixtures. We have found excellent agreement between predictions from the DGT (coupled to a Lennard-Jones equation for the bulk phases) and simulations results for both the phase and interface behavior, in the whole temperature, pressure, and concentration ranges. For all conditions explored in this work, this type-II mixture shows a three-phase equilibrium composed by a bulk immiscible liquid phase (L1) and a bulk gas phase (G) separated by a second immiscible liquid phase (L2). A similar phase distribution is obtained from the interfacial concentration profile in the whole range of conditions used in this work. This type of structure is a clear evidence that L2 completely wets the GL1 interface. The wetting behavior is also confirmed by the values and evolution of the interfacial tensions. In summary, this kind of type-II mixture does not show wetting transitions and exhibits a permanent perfect wetting in all the thermodynamic conditions explored here.
通过密度梯度理论（DGT）和分子动力学模拟，获得了II型等尺寸 Lennard-Jones 混合物沿三相平衡的润湿行为。为了在两种方法之间进行一致的比较，这种混合物的分子参数是根据等尺寸 Lennard-Jones 混合物的全局相图定义的。我们发现，在整个温度、压力和浓度范围内，DGT 的预测结果（与体相的 Lennard-Jones 方程相结合）与相行为和界面行为的模拟结果之间具有极好的一致性。对于本工作中探索的所有条件，这种II型混合物显示出由大量不混溶液相（L1）和大量气相（G）组成的三相平衡，它们由第二种不混溶液相（L2）分隔。在本工作使用的整个条件范围内，从界面浓度分布也获得了类似的相分布。这种结构类型清楚地证明 L2 完全润湿了 GL1 界面。润湿行为也通过界面张力的值和演变得到证实。总之，这种II型混合物在此处探索的所有热力学条件下均未显示出润湿转变，而是表现出永久的完全润湿。
