Abyzov Alexander S, Schmelzer Jürn W P
National Science Center, Kharkov Institute of Physics and Technology, 61108 Kharkov, Ukraine.
Institut für Physik der Universität Rostock, Wismarsche Strasse 43-45, 18057 Rostock, Germany.
J Chem Phys. 2014 Jun 28;140(24):244706. doi: 10.1063/1.4884395.
Heterogeneous nucleation in solutions on planar solid surfaces is modeled taking into account changes of the state parameters of the critical clusters in dependence on supersaturation. The account of the variation of the state parameters of the cluster phase on nucleation is performed in the framework of the generalized Gibbs' approach. A regular solution is chosen as a model for the analysis of the basic qualitative characteristics of the process. It is shown that, employing the generalized Gibbs approach, contact angle and catalytic activity factor for heterogeneous nucleation become dependent on the degree of metastability (supersaturation) of the solution. For the case of formation of a cluster in supersaturated solutions on a surface of low wettability (the macroscopic equilibrium contact angles being larger than 90°), the solid surface has only a minor influence on nucleation. In the alternative case of high wettability (for macroscopic equilibrium contact angles being less than 90°), nucleation is significantly enhanced by the solid surface. Effectively, the existence of the solid surface results in a significant shift of the spinodal to lower supersaturations as compared with homogeneous nucleation. Qualitatively, the same behavior is observed now near the new (solid surface induced) limits of instability of the solution as compared with the behavior near to the spinodal curve in the case of homogeneous nucleation.
考虑到临界团簇的状态参数随过饱和度的变化，对平面固体表面溶液中的非均相成核进行了建模。在广义吉布斯方法的框架内，考虑了成核过程中团簇相状态参数的变化。选择正则溶液作为分析该过程基本定性特征的模型。结果表明，采用广义吉布斯方法，非均相成核的接触角和催化活性因子取决于溶液的亚稳程度（过饱和度）。对于在低润湿性表面（宏观平衡接触角大于90°）的过饱和溶液中形成团簇的情况，固体表面对成核的影响较小。在高润湿性的另一种情况下（宏观平衡接触角小于90°），固体表面显著增强了成核作用。实际上，与均相成核相比，固体表面的存在导致旋节线明显向较低过饱和度移动。定性地说，与均相成核情况下旋节线曲线附近的行为相比，现在在溶液新的（由固体表面引起的）不稳定极限附近观察到相同的行为。
